reventing collisions:
1. Between aircraft; and
2. On the maneuvering area between aircraft
and obstructions.
b. Expediting and maintaining an orderly flow of
air traffic.
AIR TRAFFIC CONTROL SPECIALIST- A person
authorized to provide air traffic control service.
(See AIR TRAFFIC CONTROL.)
(See FLIGHT SERVICE STATION.)
(See ICAO term CONTROLLER.)
AIR TRAFFIC CONTROL SYSTEM COMMAND
CENTER (ATCSCC) - An Air Traffic Tactical
Operations facility responsible for monitoring and
managing the flow of air traffic throughout the NAS,
producing a safe, orderly, and expeditious flow of
traffic while minimizing delays. The following
functions are located at the ATCSCC:
a. Central Altitude Reservation Function
(CARF). Responsible for coordinating, planning,
and approving special user requirements under the
Altitude Reservation (ALTRV) concept.
(See ALTITUDE RESERVATION.)
b. Airport Reservation Office (ARO).
Responsible for approving IFR flights at designated
high density traffic airports (John F. Kennedy,
LaGuardia, and Ronald Reagan Washington
National) during specified hours.
(Refer to 14 CFR Part 93.)
(Refer to AIRPORT/FACILITY DIRECTORY.)
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c. U.S. Notice to Airmen (NOTAM) Office.
Responsible for collecting, maintaining, and distrib©\
uting NOTAMs for the U.S. civilian and military, as
well as international aviation communities.
(See NOTICE TO AIRMEN.)
d. Weather Unit. Monitor all aspects of weather
for the U.S. that might affect aviation including cloud
cover, visibility, winds, precipitation, thunderstorms,
icing, turbulence, and more. Provide forecasts based
on observations and on discussions with meteorolo©\
gists from various National Weather Service offices,
FAA facilities, airlines, and private weather services.
AIR TRAFFIC SERVICE- A generic term meaning:
a. Flight Information Service.
b. Alerting Service.
c. Air Traffic Advisory Service.
d. Air Traffic Control Service:
1. Area Control Service,
2. Approach Control Service, or
3. Airport Control Service.
AIR TRAFFIC SERVICE (ATS) ROUTES - The
term ¡°ATS Route¡± is a generic term that includes
¡°VOR Federal airways,¡± ¡°colored Federal airways,¡±
¡°jet routes,¡± and ¡°RNAV routes.¡± The term ¡°ATS
route¡± does not replace these more familiar route
names, but serves only as an overall title when listing
the types of routes that comprise the United States
route structure.
AIRBORNE DELAY- Amount of delay to be
encountered in airborne holding.
AIRCRAFT- Device(s) that are used or intended to
be used for flight in the air, and when used in air traffic
control terminology, may include the flight crew.
(See ICAO term AIRCRAFT.)
AIRCRAFT [ICAO]- Any machine that can derive
support in the atmosphere from the reactions of the air
other than the reactions of the air against the earth's
surface.
AIRCRAFT APPROACH CATEGORY- A
grouping of aircraft based on a speed of 1.3 times the
stall speed in the landing configuration at maximum
gross landing weight. An aircraft must fit in only one
category. If it is necessary to maneuver at speeds in
excess of the upper limit of a speed range for a
category, the minimums for the category for that
speed must be used. For example, an aircraft which
falls in Category A, but is circling to land at a speed
in excess of 91 knots, must use the approach
CategoryB minimums when circling to land. The
categories are as follows:
a. Category A- Speed less than 91 knots.
b. Category B- Speed 91 knots or more but less
than 121 knots.
c. Category C- Speed 121 knots or more but less
than 141 knots.
d. Category D- Speed 141 knots or more but less
than 166 knots.
e. Category E- Speed 166 knots or more.
(Refer to 14 CFR Part 97.)
AIRCRAFT CLASSES- For the purposes of Wake
Turbulence Separation Minima, ATC classifies
aircraft as Heavy, Large, and Small as follows:
a. Heavy- Aircraft capable of takeoff weights of
more than 255,000 pounds whether or not they are
operating at this weight during a particular phase of
flight.
b. Large- Aircraft of more than 41,000 pounds,
maximum certificated takeoff weight, up to 255,000
pounds.
c. Small- Aircraft of 41,000 pounds or less
maximum certificated takeoff weight.
(Refer to AIM.)
AIRCRAFT CONFLICT- Predicted conflict, within
URET, of two aircraft, or between aircraft and
airspace. A Red alert is used for conflicts when the
predicted minimum separation is 5 nautical miles or
less. A Yellow alert is used when the predicted
minimum separation is between 5 and approximately
12 nautical miles. A Blue alert is used for conflicts
between an aircraft and predefined airspace.
(See USER REQUEST EVALUATION TOOL.)
AIRCRAFT LIST (ACL)- A view available with
URET that lists aircraft currently in or predicted to be
in a particular sector's airspace. The view contains
textual flight data information in line format and may
be sorted into various orders based on the specific
needs of the sector team.
(See USER REQUEST EVALUATION TOOL.)
AIRCRAFT SURGE LAUNCH AND
RECOVERY- Procedures used at USAF bases to
provide increased launch and recovery rates in
instrument flight rules conditions. ASLAR is based
on:
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a. Reduced separation between aircraft which is
based on time or distance. Standard arrival separation
applies between participants including multiple
flights until the DRAG point. The DRAG point is a
published location on an ASLAR approach where
aircraft landing second in a formation slows to a
predetermined airspeed. The DRAG point is the
reference point at which MARSA applies as
expanding elements effect separation within a flight
or between subsequent participating flights.
b. ASLAR procedures shall be covered in a Letter
of Agreement between the responsible USAF
military ATC facility and the concerned Federal
Aviation Administration facility. Initial Approach
Fix spacing requirements are normally addressed as
a minimum.
AIRMEN'S METEOROLOGICAL
INFORMATION(See AIRMET.)
AIRMET- In©\flight weather advisories issued only
to amend the area forecast concerning weather
phenomena which are of operational interest to all
aircraft and potentially hazardous to aircraft having
limited capability because of lack of equipment,
instrumentation, or pilot qualifications. AIRMETs
concern weather of less severity than that covered by
SIGMETs or Convective SIGMETs. AIRMETs
cover moderate icing, moderate turbulence, sustained
winds of 30 knots or more at the surface, widespread
areas of ceilings less than 1,000 feet and/or visibility
less than 3 miles, and extensive mountain
obscurement.
(See AWW.)
(See CONVECTIVE SIGMET.)
(See CWA.)
(See SIGMET.)
(Refer to AIM.)
AIRPORT- An area on land or water that is used or
intended to be used for the landing and takeoff of
aircraft and includes its buildings and facilities, if
any.
AIRPORT ADVISORY AREA- The area within ten
miles of an airport without a control tower or where
the tower is not in operation, and on which a Flight
Service Station is located.
(See LOCAL AIRPORT ADVISORY.)
(Refer to AIM.)
AIRPORT ARRIVAL RATE (AAR)- A dynamic
input parameter specifying the number of arriving
aircraft which an airport or airspace can accept from
the ARTCC per hour. The AAR is used to calculate
the desired interval between successive arrival
aircraft.
AIRPORT DEPARTURE RATE (ADR)- A dynamic
parameter specifying the number of aircraft which
can depart an airport and the airspace can accept per
hour.
AIRPORT ELEVATION- The highest point of an
airport's usable runways measured in feet from mean
sea level.
(See TOUCHDOWN ZONE ELEVATION.)
(See ICAO term AERODROME ELEVATION.)
AIRPORT/FACILITY DIRECTORY- A publication
designed primarily as a pilot's operational manual
containing all airports, seaplane bases, and heliports
open to the public including communications data,
navigational facilities, and certain special notices and
procedures. This publication is issued in seven
volumes according to geographical area.
AIRPORT LIGHTING- Various lighting aids that
may be installed on an airport. Types of airport
lighting include:
a. Approach Light System (ALS)- An airport
lighting facility which provides visual guidance to
landing aircraft by radiating light beam s in a
directional pattern by which the pilot aligns the
aircraft with the extended centerline of the runway on
his/her final approach for landing. Condenser©\
Discharge Sequential Flashing Lights/Sequenced
Flashing Lights may be installed in conjunction with
the ALS at some airports. Types of Approach Light
Systems are:
1. ALSF©\1- Approach Light System with
Sequenced Flashing Lights in ILS Cat©\I configura©\
tion.
2. ALSF©\2- Approach Light System with
Sequenced Flashing Lights in ILS Cat©\II configura©\
tion. The ALSF©\2 may operate as an SSALR when
weather conditions permit.
3. SSALF- Simplified Short Approach Light
System with Sequenced Flashing Lights.
4. SSALR- Simplified Short Approach Light
System with Runway Alignment Indicator Lights.
5. MALSF- Medium Intensity Approach Light
System with Sequenced Flashing Lights.
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6. MALSR- Medium Intensity Approach Light
System with Runway Alignment Indicator Lights.
7. LDIN- Lead©\in©\light system- Consists of
one or more series of flashing lights installed at or
near ground level that provides positive visual
guidance along an approach path, either curving or
straight, where special problems exist with hazardous
terrain, obstructions, or noise abatement procedures.
8. RAIL- Runway Alignment Indicator Lights-
Sequenced Flashing Lights which are installed only
in combination with other light systems.
9. ODALS- Omnidirectional Approach Light©\
ing System consists of seven omnidirectional
flashing lights located in the approach area of a
nonprecision runway. Five lights are located on the
runway centerline extended with the first light
located 300 feet from the threshold and extending at
equal intervals up to 1,500 feet from the threshold.
The other two lights are located, one on each side of
the runway threshold, at a lateral distance of 40 feet
from the runway edge, or 75 feet from the runway
edge when installed on a runway equipped with a
VASI.
(Refer to FAAO JO 6850.2, VISUAL GUIDANCE
LIGHTING SYSTEMS.)
b. Runway Lights/Runway Edge Lights- Lights
having a prescribed angle of emission used to define
the lateral limits of a runway. Runway lights are
uniformly spaced at intervals of approximately 200
feet, and the intensity may be controlled or preset.
c. Touchdown Zone Lighting- Two rows of
transverse light bars located symmetrically about the
runway centerline normally at 100 foot intervals. The
basic system extends 3,000 feet along the runway.
d. Runway Centerline Lighting- Flush centerline
lights spaced at 50©\foot intervals beginning 75 feet
from the landing threshold and extending to within 75
feet of the opposite end of the runway.
e. Threshold Lights- Fixed green lights arranged
symmetrically left and right of the runway centerline,
identifying the runway threshold.
f. Runway End Identifier Lights (REIL)- Two
synchronized flashing lights, one on each side of the
runway threshold, which provide rapid and positive
identification of the approach end of a particular
runway.
g. Visual Approach Slope Indicator (VASI)- An
airport lighting facility providing vertical visual
approach slope guidance to aircraft during approach
to landing by radiating a directional pattern of high
intensity red and white focused light beams which
indicate to the pilot that he/she is ¡°on path¡± if he/she
sees red/white, ¡°above path¡± if white/white, and
¡°below path¡± if red/red. Some airports serving large
aircraft have three©\bar VASIs which provide two
visual glide paths to the same runway.
h. recision Approach Path Indicator (PAPI)- An
airport lighting facility, similar to VASI, providing
vertical approach slope guidance to aircraft during
approach to landing. PAPIs consist of a single row of
either two or four lights, normally installed on the left
side of the runway, and have an effective visual range
of about 5 miles during the day and up to 20 miles at
night. PAPIs radiate a directional pattern of high
intensity red and white focused light beams which
indicate that the pilot is ¡°on path¡± if the pilot sees an
equal number of white lights and red lights, with
white to the left of the red; ¡°above path¡± if the pilot
sees more white than red lights; and ¡°below path¡± if
the pilot sees more red than white lights.
i. Boundary Lights- Lights defining the perimeter
of an airport or landing area.
(Refer to AIM.)
AIRPORT MARKING AIDS- Markings used on
runway and taxiway surfaces to identify a specific
runway, a runway threshold, a centerline, a hold line,
etc. A runway should be marked in accordance with
its present usage such as:
a. Visual.
b. Nonprecision instrument.
c. recision instrument.
(Refer to AIM.)
AIR PORT REFERENCE POINT (ARP)- The
approximate geometric center of all usable runway
surfaces.
AIRPORT RESERVATION OFFICE- Office re©\
sponsible for monitoring the operation of the high
density rule. Receives and processes requests for
IFR-operations at high density traffic airports.
AIRPORT ROTATING BEACON- A visual
NAVAID operated at many airports. At civil airports,
alternating white and green flashes indicate the
location of the airport. At military airports, the
beacons flash alternately white and green, but are
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differentiated from civil beacons by dualpeaked (two
quick) white flashes between the green flashes.
(See INSTRUMENT FLIGHT RULES.)
(See SPECIAL VFR OPERATIONS.)
(See ICAO term AERODROME BEACON.)
(Refer to AIM.)
AIRPORT STREAM FILTER (ASF)- An on/off
filter that allows the conflict notification function to
be inhibited for arrival streams into single or multiple
airports to prevent nuisance alerts.
AIRPORT SURFACE DETECTION EQUIPMENT
(ASDE)- Surveillance equipment specifically de©\
signed to detect aircraft, vehicular traffic, and other
objects, on the surface of an airport, and to present the
image on a tower display. Used to augment visual
observation by tower personnel of aircraft and/or
vehicular movements on runways and taxiways.
There are three ASDE systems deployed in the NAS:
a. ASDE-3- a Surface Movement Radar.
b. ASDE-X- a system that uses a X-band Surface
Movement Radar and multilateration. Data from
these two sources are fused and presented on a digital
display.
c. ASDE-3X- an ASDE-X system that uses the
ASDE-3 Surface Movement Radar.
AIRPORT SURVEILLANCE RADAR- Approach
control radar used to detect and display an aircraft's
position in the terminal area. ASR provides range and
azimuth information but does not provide elevation
data. Coverage of the ASR can extend up to 60 miles.
AIRPORT TAXI CHARTS(See AERONAUTICAL CHART.)
AIRPORT TRAFFIC CONTROL SERVICE- A
service provided by a control tower for aircraft
operating on the movement area and in the vicinity of
an airport.
(See MOVEMENT AREA.)
(See TOWER.)
(See ICAO term AERODROME CONTROL
SERVICE.)
AIRPORT TRAFFIC CONTROL TOWER(See TOWER.)
AIRSPACE CONFLICT- Predicted conflict of an
aircraft and active Special Activity Airspace (SAA).
AIRSPACE FLOW PROGRAM (AFP)- AFP is a
Traffic Management (TM) process administered by
the Air Traffic Control System Command Center
(ATCSCC) where aircraft are assigned an Expect
Departure Clearance Time (EDCT) in order to
manage capacity and demand for a specific area of the
National Airspace System (NAS). The purpose of the
program is to mitigate the effects of en route
constraints. It is a flexible program and may be
implemented in various forms depending upon the
needs of the air traffic system.
AIRSPACE HIERARCHY- Within the airspace
classes, there is a hierarchy and, in the event of an
overlap of airspace: Class A preempts Class B, Class
B preempts Class C, Class C preempts Class D, Class
D preempts Class E, and Class E preempts Class G.
AIRSPEED- The speed of an aircraft relative to its
surrounding air mass. The unqualified term
¡°airspeed¡± means one of the following:
a. Indicated Airspeed- The speed shown on the
aircraft airspeed indicator. This is the speed used in
pilot/controller communications under the general
term ¡°airspeed.¡±
(Refer to 14 CFR Part 1.)
b. True Airspeed- The airspeed of an aircraft
relative to undisturbed air. Used primarily in flight
planning and en route portion of flight. When used in
pilot/controller communications, it is referred to as
¡°true airspeed¡± and not shortened to ¡°airspeed.¡±
AIRSTART- The starting of an aircraft engine while
the aircraft is airborne, preceded by engine shutdown
during training flights or by actual engine failure.
AIRWAY- A Class E airspace area established in the
form of a corridor, the centerline of which is defined
by radio navigational aids.
(See FEDERAL AIRWAYS.)
(See ICAO term AIRWAY.)
(Refer to 14 CFR Part 71.)
(Refer to AIM.)
AIRWAY [ICAO]- A control area or portion thereof
established in the form of corridor equipped with
radio navigational aids.
AIRWAY BEACON- Used to mark airway segments
in remote mountain areas. The light flashes Morse
Code to identify the beacon site.
(Refer to AIM.)
AIT(See AUTOMATED INFORMATION
TRANSFER.)
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ALERFA (Alert Phase) [ICAO]- A situation wherein
apprehension exists as to the safety of an aircraft and
its occupants.
ALERT- A notification to a position that there
is an aircraft©\to©\aircraft or aircraft©\to©\airspace
conflict, as detected by Automated Problem
Detection (APD).
ALERT AREA(See SPECIAL USE AIRSPACE.)
ALERT NOTICE- A request originated by a flight
service station (FSS) or an air route traffic control
center (ARTCC) for an extensive communication
search for overdue, unreported, or missing aircraft.
ALERTING SERVICE- A service provided to notify
appropriate organizations regarding aircraft in need
of search and rescue aid and assist such organizations
as required.
ALNOT(See ALERT NOTICE.)
ALONG-TRACK DISTANCE (ATD)- The distance
measured from a point©\in©\space by systems using
area navigation reference capabilities that are not
subject to slant range errors.
ALPHANUMERIC DISPLAY- Letters and numer©\
als used to show identification, altitude, beacon code,
and other information concerning a target on a radar
display.
(See AUTOMATED RADAR TERMINAL
SYSTEMS.)
ALTERNATE AERODROME [ICAO]- An aero©\
drome to which an aircraft may proceed when it
becomes either impossible or inadvisable to proceed
to or to land at the aerodrome of intended landing.
Note:The aerodrome from which a flight departs
may also be an en©\route or a destination alternate
aerodrome for the flight.
ALTERNATE AIRPORT- An airport at which an
aircraft may land if a landing at the intended airport
becomes inadvisable.
(See ICAO term ALTERNATE AERODROME.)
ALTIMETER SETTING- The barometric pressure
reading used to adjust a pressure altimeter for
variations in existing atmospheric pressure or to the
standard altimeter setting (29.92).
(Refer to 14 CFR Part 91.)
(Refer to AIM.)
ALTITUDE- The height of a level, point, or object
measured in feet Above Ground Level (AGL) or from
Mean Sea Level (MSL).
(See FLIGHT LEVEL.)
a. MSL Altitude- Altitude expressed in feet
measured from mean sea level.
b. AGL Altitude- Altitude expressed in feet
measured above ground level.
c. Indicated Altitude- The altitude as shown by an
altimeter. On a pressure or barometric altimeter it is
altitude as shown uncorrected for instrument error
and uncompensated for variation from standard
atmospheric conditions.
(See ICAO term ALTITUDE.)
ALTITUDE [ICAO]- The vertical distance of a level,
a point or an object considered as a point, measured
from mean sea level (MSL).
ALTITUDE READOUT- An aircraft's altitude,
transmitted via the Mode C transponder feature, that
is visually displayed in 100©\foot increments on a
radar scope having readout capability.
(See ALPHANUMERIC DISPLAY.)
(See AUTOMATED RADAR TERMINAL
SYSTEMS.)
(Refer to AIM.)
ALTITUDE RESERVATION- Airspace utilization
under prescribed conditions normally employed for
the mass movement of aircraft or other special user
requirem ents which cannot otherwise be
accomplished. ALTRVs are approved by the
appropriate FAA facility.
(See AIR TRAFFIC CONTROL SYSTEM
COMMAND CENTER.)
ALTITUDE RESTRICTION- An altitude or alti©\
tudes, stated in the order flown, which are to be
maintained until reaching a specific point or time.
Altitude restrictions may be issued by ATC due to
traffic, terrain, or other airspace considerations.
ALTITUDE RESTRICTIONS ARE CANCELED-
Adherence to previously imposed altitude restric©\
tions is no longer required during a climb or descent.
ALTRV(See ALTITUDE RESERVATION.)
AMVER(See AUTOMATED MUTUAL©\ASSISTANCE
VESSEL RESCUE SYSTEM.)
APB(See AUTOMATED PROBLEM DETECTION
BOUNDARY.)
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PCG A-11
APD(See AUTOMATED PROBLEM DETECTION.)
APDIA(See AUTOMATED PROBLEM DETECTION
INHIBITED AREA.)
APPROACH CLEARANCE- Authorization by
ATC for a pilot to conduct an instrument approach.
The type of instrument approach for which a
clearance and other pertinent information is provided
in the approach clearance when required.
(See CLEARED APPROACH.)
(See INSTRUMENT APPROACH
PROCEDURE.)
(Refer to AIM.)
(Refer to 14 CFR Part 91.)
APPROACH CONTROL FACILITY- A terminal
ATC facility that provides approach control service in
a terminal area.
(See APPROACH CONTROL SERVICE.)
(See RADAR APPROACH CONTROL
FACILITY.)
APPROACH CONTROL SERVICE- Air traffic
control service provided by an approach control
facility for arriving and departing VFR/IFR aircraft
and, on occasion, en route aircraft. At some airports
not served by an approach control facility, the
ARTCC provides limited approach control service.
(See ICAO term APPROACH CONTROL
SERVICE.)
(Refer to AIM.)
APPROACH CONTROL SERVICE [ICAO]- Air
traffic control service for arriving or departing
controlled flights.
APPROACH GATE- An imaginary point used
within ATC as a basis for vectoring aircraft to the
final approach course. The gate will be established
along the final approach course 1 mile from the final
approach fix on the side away from the airport and
will be no closer than 5 miles from the landing
threshold.
APPROACH LIGHT SYSTEM(See AIRPORT LIGHTING.)
APPROACH SEQUENCE- The order in which
aircraft are positioned while on approach or awaiting
approach clearance.
(See LANDING SEQUENCE.)
(See ICAO term APPROACH SEQUENCE.)
APPROACH SEQUENCE [ICAO]- The order in
which two or more aircraft are cleared to approach to
land at the aerodrome.
APPROACH SPEED- The recommended speed
contained in aircraft manuals used by pilots when
making an approach to landing. This speed will vary
for different segments of an approach as well as for
aircraft weight and configuration.
APPROPRIATE ATS AUTHORITY [ICAO]- The
relevant authority designated by the State responsible
for providing air traffic services in the airspace
concerned. In the United States, the ¡°appropriate ATS
authority¡± is the Program Director for Air Traffic
Planning and Procedures, ATP©\1.
APPROPRIATE AUTHORITYa. Regarding flight over the high seas: the relevant
authority is the State of Registry.
b. Regarding flight over other than the high seas:
the relevant authority is the State having sovereignty
over the territory being overflown.
APPROPRIATE OBSTACLE CLEARANCE
MINIMUM ALTITUDE- Any of the following:
(See MINIMUM EN ROUTE IFR ALTITUDE.)
(See MINIMUM IFR ALTITUDE.)
(See MINIMUM OBSTRUCTION CLEARANCE
ALTITUDE.)
(See MINIMUM VECTORING ALTITUDE.)
APPROPRIATE TERRAIN CLEARANCE
MINIMUM ALTITUDE- Any of the following:
(See MINIMUM EN ROUTE IFR ALTITUDE.)
(See MINIMUM IFR ALTITUDE.)
(See MINIMUM OBSTRUCTION CLEARANCE
ALTITUDE.)
(See MINIMUM VECTORING ALTITUDE.)
APRON- A defined area on an airport or heliport
intended to accommodate aircraft for purposes of
loading or unloading passengers or cargo, refueling,
parking, or maintenance. With regard to seaplanes, a
ramp is used for access to the apron from the water.
(See ICAO term APRON.)
APRON [IC AO]- A defined area, on a land
aerodrome, intended to accommodate aircraft for
purposes of loading or unloading passengers, mail or
cargo, refueling, parking or maintenance.
ARC- The track over the ground of an aircraft flying
at a constant distance from a navigational aid by
reference to distance measuring equipment (DME).
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AREA CONTROL CENTER [ICAO]- An air traffic
control facility primarily responsible for ATC
services being provided IFR aircraft during the en
route phase of flight. The U.S. equivalent facility is
an air route traffic control center (ARTCC).
AREA NAVIGATION- Area Navigation (RNAV)
provides enhanced navigational capability to the
pilot. RNAV equipment can compute the airplane
position, actual track and ground speed and then
provide meaningful information relative to a route of
flight selected by the pilot. Typical equipment will
provide the pilot with distance, time, bearing and
crosstrack error relative to the selected ¡°TO¡± or
¡°active¡± waypoint and the selected route. Several
distinctly different navigational systems with
different navigational performance characteristics
are capable of providing area navigational functions.
Present day RNAV includes INS, LORAN, VOR/
DME, and GPS systems. Modern multi©\sensor
systems can integrate one or more of the above
systems to provide a more accurate and reliable
navigational system. Due to the different levels of
performance, area navigational capabilities can
satisfy different levels of required navigational
performance (RNP). The major types of equipment
are:
a. VORTAC referenced or Course Line Computer
(CLC) systems, which account for the greatest
number of RNAV units in use. To function, the CLC
must be within the service range of a VORTAC.
b. OMEGA/VLF, although two separate systems,
can be considered as one operationally. A long©\range
navigation system based upon Very Low Frequency
radio signals transmitted from a total of 17 stations
worldwide.
c. Inertial (INS) systems, which are totally
self©\contained and require no information from
external references. They provide aircraft position
and navigation information in response to signals
resulting from inertial effects on components within
the system.
d. MLS Area Navigation (MLS/RNAV), which
provides area navigation with reference to an MLS
ground facility.
e. LORAN©\C is a long©\range radio navigation
system that uses ground waves transmitted at low
frequency to provide user position information at
ranges of up to 600 to 1,200 nautical miles at both en
route and approach altitudes. The usable signal
coverage areas are determined by the signal©\to©\noise
ratio, the envelope©\to©\cycle difference, and the
geometric relationship between the positions of the
user and the transmitting stations.
f. GPS is a space©\base radio positioning,
navigation, and time©\transfer system. The system
provides highly accurate position and velocity
information, and precise time, on a continuous global
basis, to an unlimited number of properly equipped
users. The system is unaffected by weather, and
provides a worldwide common grid reference
system.
(See ICAO term AREA NAVIGATION.)
AREA NAVIGATION [IC AO]- A method of
navigation which permits aircraft operation on any
desired flight path within the coverage of station©\
referenced navigation aids or within the limits of the
capability of self©\contained aids, or a combination of
these.
AREA NAVIGATION (RNAV) APPROACH
CONFIGURATION:
a. STANDARD T- An RNAV approach whose
design allows direct flight to any one of three initial
approach fixes (IAF) and eliminates the need for
procedure turns. The standard design is to align the
procedure on the extended centerline with the missed
approach point (MAP) at the runway threshold, the
final approach fix (FAF), and the initial approach/
intermediate fix (IAF/IF). The other two IAFs will be
established perpendicular to the IF.
b. MODIFIED T- An RNAV approach design for
single or multiple runways where terrain or
operational constraints do not allow for the standard
T. The ¡°T¡± may be modified by increasing or
decreasing the angle from the corner IAF(s) to the IF
or by eliminating one or both corner IAFs.
c. STANDARD I- An RNAV approach design for
a single runway with both corner IAFs eliminated.
Course reversal or radar vectoring may be required at
busy terminals with multiple runways.
d. TERMINAL ARRIVAL AREA (TAA)- The
TAA is controlled airspace established in conjunction
with the Standard or Modified T and I RNAV
approach configurations. In the standard TAA, there
are three areas: straight©\in, left base, and right base.
The arc boundaries of the three areas of the TAA are
published portions of the approach and allow aircraft
to transition from the en route structure direct to the
nearest IAF. TAAs will also eliminate or reduce
Pilot/Controller Glossary 7/31/08
Pilot/Controller Glossary 2/14/08
PCG A-13
feeder routes, departure extensions, and procedure
turns or course reversal.
1. STRAIGHT©\IN AREA- A 30NM arc
centered on the IF bounded by a straight line
extending through the IF perpendicular to the
intermediate course.
2. LEFT BASE AREA- A 30NM arc centered
on the right corner IAF. The area shares a boundary
with the straight©\in area except that it extends out for
30NM from the IAF and is bounded on the other side
by a line extending from the IF through the FAF to the
arc.
3. RIGHT BASE AREA- A 30NM arc centered
on the left corner IAF. The area shares a boundary
with the straight©\in area except that it extends out for
30NM from the IAF and is bounded on the other side
by a line extending from the IF through the FAF to the
arc.
ARINC- An acronym for Aeronautical Radio, Inc.,
a corporation largely owned by a group of airlines.
ARINC is licensed by the FCC as an aeronautical
station and contracted by the FAA to provide
communications support for air traffic control and
meteorological services in portions of international
airspace.
ARMY AVIATION FLIGHT INFORMATION
BULLETIN- A bulletin that provides air operation
data covering Army, National Guard, and Army
Reserve aviation activities.
ARO(See AIRPORT RESERVATION OFFICE.)
ARRESTING SYSTEM- A safety device consisting
of two major components, namely, engaging or
catching devices and energy absorption devices for
the purpose of arresting both tailhook and/or
nontailhook©\equipped aircraft. It is used to prevent
aircraft from overrunning runways when the aircraft
cannot be stopped after landing or during aborted
takeoff. Arresting systems have various names; e.g.,
arresting gear, hook device, wire barrier cable.
(See ABORT.)
(Refer to AIM.)
ARRIVAL AIRCRAFT INTERVAL- An internally
generated program in hundredths of minutes based
upon the AAR. AAI is the desired optimum interval
between successive arrival aircraft over the vertex.
ARRIVAL CENTER- The ARTCC having jurisdic©\
tion for the impacted airport.
ARRIVAL DELAY- A parameter which specifies a
period of time in which no aircraft will be metered for
arrival at the specified airport.
ARRIVAL SECTOR- An operational control sector
containing one or more meter fixes.
ARRIVAL SECTOR ADVIS ORY LIS T- An
ordered list of data on arrivals displayed at the
PVD/MDM of the sector which controls the meter
fix.
ARRIVAL SEQUENCING PROGRAM- The auto©\
mated program designed to assist in sequencing
aircraft destined for the same airport.
ARRIVAL TIME- The time an aircraft touches down
on arrival.
ARSR(See AIR ROUTE SURVEILLANCE RADAR.)
ARTCC(See AIR ROUTE TRAFFIC CONTROL
CENTER.)
ARTS(See AUTOMATED RADAR TERMINAL
SYSTEMS.)
ASDA(See ACCELERATE©\STOP DISTANCE
AVAILABLE.)
ASDA [ICAO]-
(See ICAO Term ACCELERATE©\STOP
DISTANCE AVAILABLE.)
ASDE(See AIRPORT SURFACE DETECTION
EQUIPMENT.)
ASF(See AIRPORT STREAM FILTER.)
ASLAR(See AIRCRAFT SURGE LAUNCH AND
RECOVERY.)
ASP(See ARRIVAL SEQUENCING PROGRAM.)
ASR(See AIRPORT SURVEILLANCE RADAR.)
ASR APPROACH(See SURVEILLANCE APPROACH.)
7/31/08 Pilot/Controller Glossary
2/14/08
PCG A-14
ASSOCIATED- A radar target displaying a data
block with flight identification and altitude
information.
(See UNASSOCIATED.)
ATC(See AIR TRAFFIC CONTROL.)
ATC ADVISES- Used to prefix a message of
noncontrol information when it is relayed to an
aircraft by other than an air traffic controller.
(See ADVISORY.)
ATC ASSIGNED AIRSPACE- Airspace of defined
vertical/lateral limits, assigned by ATC, for the
purpose of providing air traffic segregation between
the specified activities being conducted within the
assigned airspace and other IFR air traffic.
(See SPECIAL USE AIRSPACE.)
ATC CLEARANCE(See AIR TRAFFIC CLEARANCE.)
ATC CLEARS- Used to prefix an ATC clearance
when it is relayed to an aircraft by other than an air
traffic controller.
ATC INSTRUCTIONS- Directives issued by air
traffic control for the purpose of requiring a pilot to
take specific actions; e.g., ¡°Turn left heading two five
zero,¡± ¡°Go around,¡± ¡°Clear the runway.¡±
(Refer to 14 CFR Part 91.)
ATC PREFERRED ROUTE NOTIFICATION-
URET notification to the appropriate controller of the
need to determine if an ATC preferred route needs to
be applied, based on destination airport.
(See ROUTE ACTION NOTIFICATION.)
(See USER REQUEST EVALUATION TOOL.)
ATC PREFERRED ROUTES- Preferred routes that
are not automatically applied by Host.
ATC REQUESTS- Used to prefix an ATC request
when it is relayed to an aircraft by other than an air
traffic controller.
ATCAA(See ATC ASSIGNED AIRSPACE.)
ATCRBS(See RADAR.)
ATCSCC(See AIR TRAFFIC CONTROL SYSTEM
COMMAND CENTER.)
ATCT(See TOWER.)
ATD(See ALONG-TRACK DISTANCE.)
ATIS(See AUTOMATIC TERMINAL INFORMATION
SERVICE.)
ATIS [ICAO]-
(See ICAO Term AUTOMATIC TERMINAL
INFORMATION SERVICE.)
ATS ROUTE [ICAO]- A specified route designed for
channelling the flow of traffic as necessary for the
provision of air traffic services.
Note:The term ¡°ATS Route¡± is used to mean vari©\
ously, airway, advisory route, controlled or
uncontrolled route, arrival or departure, etc.
AUTOLAND APPROACH- An autoland approach
is a precision instrument approach to touchdown and,
in some cases, through the landing rollout. An
autoland approach is performed by the aircraft
autopilot which is receiving position information
and/or steering commands from onboard navigation
equipment.
Note:Autoland and coupled approaches are flown
in VFR and IFR. It is common for carriers to require
their crews to fly coupled approaches and autoland
approaches (if certified) when the weather condi©\
tions are less than approximately 4,000 RVR.
(See COUPLED APPROACH.)
AUTOMATED INFORMATION TRANSFER- A
precoordinated process, specifically defined in
facility directives, during which a transfer of altitude
control and/or radar identification is accomplished
without verbal coordination between controllers
using information communicated in a full data block.
AUTOMATED MUTUAL©\ASSISTANCE VESSEL
RESCUE SYSTEM- A facility which can deliver, in
a matter of minutes, a surface picture (SURPIC) of
vessels in the area of a potential or actual search and
rescue incident, including their predicted positions
and their characteristics.
(See FAAO JO 7110.65, Para 10-6-4, INFLIGHT
CONTINGENCIES.)
AUTOMATED PROBLEM DETECTION (APD)-
An Automation Processing capability that compares
trajectories in order to predict conflicts.
Pilot/Controller Glossary 7/31/08
Pilot/Controller Glossary 2/14/08
PCG A-15
AUTOMATED PROBLEM DETECTION
BOUNDARY (APB)- The adapted distance beyond
a facilities boundary defining the airspace within
which URET performs conflict detection.
(See USER REQUEST EVALUATION TOOL.)
AUTOMATED PROBLEM DETECTION IN©\
HIBITED AREA (APDIA)- Airspace surrounding a
terminal area within which APD is inhibited for all
flights within that airspace.
AUTOMATED RADAR TERMINAL SYSTEMS
(ARTS)- A generic term for several tracking systems
included in the Terminal Automation Systems (TAS).
ARTS plus a suffix roman numeral denotes a major
modification to that system.
a. ARTS IIIA. The Radar Tracking and Beacon
Tracking Level (RT&BTL) of the modular,
programmable automated radar terminal system.
ARTS IIIA detects, tracks, and predicts primary as
well as secondary radar©\derived aircraft targets. This
more sophisticated computer©\driven system up©\
grades the existing ARTS III system by providing
improved tracking, continuous data recording, and
fail©\soft capabilities.
b. Common ARTS. Includes ARTS IIE, ARTS
IIIE; and ARTS IIIE with ACD (see DTAS) which
combines functionalities of the previous ARTS
systems.
c. rogram mable Indicator Data Processor
(P IDP). The PIDP is a modification to the
AN/TPX-42 interrogator system currently installed
in fixed RAPCONs. The PIDP detects, tracks, and
predicts secondary radar aircraft targets. These are
displayed by means of computer-generated symbols
and alphanumeric characters depicting flight identifi©\
cation, aircraft altitude, ground speed, and flight plan
data. Although primary radar targets are not tracked,
they are displayed coincident with the secondary
radar targets as well as with the other symbols and
alphanumerics. The system has the capability of
interfacing with ARTCCs.
AUTOMATED WEATHER SYSTEM- Any of the
automated weather sensor platforms that collect
weather data at airports and disseminate the weather
information via radio and/or landline. The systems
currently consist of the Automated Surface Observ©\
ing System (ASOS), Automated Weather Sensor
System (AWSS) and Automated Weather Observa©\
tion System (AWOS).
AUTOMATED UNICOM- Provides completely
automated weather, radio check capability and airport
advisory information on an Automated UNICOM
system. These systems offer a variety of features,
typically selectable by microphone clicks, on the
UNICOM frequency. Availability will be published
in the Airport/Facility Directory and approach charts.
AUTOMATIC ALTITUDE REPORT(See ALTITUDE READOUT.)
AUTOMATIC ALTITUDE REPORTING- That
function of a transponder which responds to Mode C
interrogations by transmitting the aircraft's altitude
in 100©\foot increments.
AUTOMATIC CARRIER LANDING SYSTEM-
U.S. Navy final approach equipment consisting of
precision tracking radar coupled to a computer data
link to provide continuous information to the aircraft,
monitoring capability to the pilot, and a backup
approach system.
AUTOMATIC DEPENDENT SURVEILLANCE
(ADS) [ICAO]- A surveillance technique in which
aircraft automatically provide, via a data link, data
derived from on-board navigation and position
fixing systems, including aircraft identification, four
dimensional position and additional data as
appropriate.
AUTOMATIC DEPENDENT SURVEILLANCE-
BROADCAST (ADS©\B)- A surveillance system in
which an aircraft or vehicle to be detected is fitted
with cooperative equipment in the form of a data link
transmitter. The aircraft or vehicle periodically
broadcasts its GPS-derived position and other
information such as velocity over the data link, which
is received by a ground-based transmitter/receiver
(transceiver) for processing and display at an air
traffic control facility.
(See GLOBAL POSITIONING SYSTEM.)
(See GROUND-BASED TRANSCEIVER.)
AUTOMATIC DEPENDENT SURVEILLANCE-
CONTRACT (ADS-C)- A data link position
reporting system, controlled by a ground station, that
establishes contracts with an aircraft's avionics that
occur automatically whenever specific events occur,
or specific time intervals are reached.
AUTOMATIC DIRECTION FINDER- An aircraft
radio navigation system which senses and indicates
the direction to a L/MF nondirectional radio beacon
(NDB) ground transmitter. Direction is indicated to
7/31/08 Pilot/Controller Glossary
2/14/08
PCG A-16
the pilot as a magnetic bearing or as a relative bearing
to the longitudinal axis of the aircraft depending on
the type of indicator installed in the aircraft. In certain
applications, such as military, ADF operations may
be based on airborne and ground transmitters in the
VHF/UHF frequency spectrum.
(See BEARING.)
(See NONDIRECTIONAL BEACON.)
AUTOMATIC FLIGHT INFORMATION
SERVICE (AFIS) - ALASKA FSSs ONLY- The
continuous broadcast of recorded non-control
information at airports in Alaska where a FSS
provides local airport advisory service. The AFIS
broadcast automates the repetitive transmission of
essential but routine information such as weather,
wind, altimeter, favored runway, breaking action,
airport NOTAMs, and other applicable information.
The information is continuously broadcast over a
discrete VHF radio frequency (usually the ASOS
frequency.)
AUTOMATIC TERMINAL INFORMATION
SERVICE- The continuous broadcast of recorded
noncontrol information in selected terminal areas. Its
purpose is to improve controller effectiveness and to
relieve frequency congestion by automating the
repetitive transmission of essential but routine
information; e.g., ¡°Los Angeles information Alfa.
One three zero zero Coordinated Universal Time.
Weather, measured ceiling two thousand overcast,
visibility three, haze, smoke, temperature seven one,
dew point five seven, wind two five zero at five,
altimeter two niner niner six. I©\L©\S Runway Two Five
Left approach in use, Runway Two Five Right closed,
advise you have Alfa.¡±
(See ICAO term AUTOMATIC TERMINAL
INFORMATION SERVICE.)
(Refer to AIM.)
AUTOMATIC TERMINAL INFORMATION
SERVICE [ICAO]- The provision of current, routine
information to arriving and departing aircraft by
means of continuous and repetitive broadcasts
throughout the day or a specified portion of the day.
AUTOROTATION- A rotorcraft flight condition in
which the lifting rotor is driven entirely by action of
the air when the rotorcraft is in motion.
a. Autorotative Landing/Touchdown Autorota©\
tion. Used by a pilot to indicate that the landing will
be made without applying power to the rotor.
b. Low Level Autorotation. Commences at an
altitude well below the traffic pattern, usually below
100 feet AGL and is used primarily for tactical
military training.
c. 180 degrees Autorotation. Initiated from a
downwind heading and is commenced well inside the
normal traffic pattern. ¡°Go around¡± may not be
possible during the latter part of this maneuver.
AVAILABLE LANDING DISTANCE (ALD)- The
portion of a runway available for landing and roll©\out
for aircraft cleared for LAHSO. This distance is
measured from the landing threshold to the
hold©\short point.
AVIATION WEATHER SERVIC E- A service
provided by the National Weather Service (NWS) and
FAA which collects and disseminates pertinent
weather information for pilots, aircraft operators, and
ATC. Available aviation weather reports and
forecasts are displayed at each NWS office and FAA
FSS.
(See EN ROUTE FLIGHT ADVISORY
SERVICE.)
(See TRANSCRIBED WEATHER BROADCAST.)
(See WEATHER ADVISORY.)
(Refer to AIM.)
AWW(See SEVERE WEATHER FORECAST
ALERTS.)
AZIMUTH (MLS)- A magnetic bearing extending
from an MLS navigation facility.
Note:Azimuth bearings are described as magnetic
and are referred to as ¡°azimuth¡± in radio telephone
communications.
Pilot/Controller Glossary 7/31/08
Pilot/Controller Glossary 2/14/08
PCG B-1
B
BACK©\TAXI- A term used by air traffic controllers
to taxi an aircraft on the runway opposite to the traffic
flow. The aircraft may be instructed to back©\taxi to
the beginning of the runway or at some point before
reaching the runway end for the purpose of departure
or to exit the runway.
BASE LEG(See TRAFFIC PATTERN.)
BEACON(See AERONAUTICAL BEACON.)
(See AIRPORT ROTATING BEACON.)
(See AIRWAY BEACON.)
(See MARKER BEACON.)
(See NONDIRECTIONAL BEACON.)
(See RADAR.)
BEARING- The horizontal direction to or from any
point, usually measured clockwise from true north,
magnetic north, or some other reference point
through 360 degrees.
(See NONDIRECTIONAL BEACON.)
BELOW MINIMUMS- Weather conditions below
the minimums prescribed by regulation for the
particular action involved; e.g., landing minimums,
takeoff minimums.
BLAST FENCE- A barrier that is used to divert or
dissipate jet or propeller blast.
BLIND SPEED- The rate of departure or closing of
a target relative to the radar antenna at which
cancellation of the primary radar target by moving
target indicator (MTI) circuits in the radar equipment
causes a reduction or complete loss of signal.
(See ICAO term BLIND VELOCITY.)
BLIND SPOT- An area from which radio
transmissions and/or radar echoes cannot be
received. The term is also used to describe portions
of the airport not visible from the control tower.
BLIND TRANSMISSION(See TRANSMITTING IN THE BLIND.)
BLIND VELOCITY [ICAO]- The radial velocity of
a moving target such that the target is not seen on
primary radars fitted with certain forms of fixed echo
suppression.
BLIND ZONE(See BLIND SPOT.)
BLOCKED- Phraseology used to indicate that a
radio transmission has been distorted or interrupted
due to multiple simultaneous radio transmissions.
BOUNDARY LIGHTS(See AIRPORT LIGHTING.)
BRAKING ACTION (GOOD, FAIR, POOR, OR
NIL)- A report of conditions on the airport
movement area providing a pilot with a degree/
quality of braking that he/she might expect. Braking
action is reported in terms of good, fair, poor, or nil.
(See RUNWAY CONDITION READING.)
BRAKING ACTION ADVISORIES- When tower
controllers have received runway braking action
reports which include the terms ¡°poor¡± or ¡°nil,¡± or
whenever weather conditions are conducive to
deteriorating or rapidly changing runway braking
conditions, the tower will include on the ATIS
broadcast the statement, ¡°BRAKING ACTION
ADVISORIES ARE IN EFFECT.¡± During the time
Braking Action Advisories are in effect, ATC will
issue the latest braking action report for the runway
in use to each arriving and departing aircraft. Pilots
should be prepared for deteriorating braking
conditions and should request current runway
condition inform ation if not volunteered by
controllers. Pilots should also be prepared to provide
a descriptive runway condition report to controllers
after landing.
BREAKOUT- A technique to direct aircraft out of
the approach stream. In the context of close parallel
operations, a breakout is used to direct threatened
aircraft away from a deviating aircraft.
BROADCAST- Transmission of information for
which an acknowledgement is not expected.
(See ICAO term BROADCAST.)
BROADCAST [ICAO]- A transmission of informa©\
tion relating to air navigation that is not addressed to
a specific station or stations.
Pilot/Controller Glossary 2/14/08
PCG C-1
C
CALCULATED LANDING TIME- A term that may
be used in place of tentative or actual calculated
landing time, whichever applies.
CALL FOR RELEASE- Wherein the overlying
ARTCC requires a terminal facility to initiate verbal
coordination to secure ARTCC approval for release
of a departure into the en route environment.
CALL UP- Initial voice contact between a facility
and an aircraft, using the identification of the unit
being called and the unit initiating the call.
(Refer to AIM.)
CANADIAN MINIMUM NAVIGATION PERFOR©\
MANCE SPECIFICATION AIRSPACE- That
portion of Canadian domestic airspace within which
MNPS separation may be applied.
CARDINAL ALTITUDES - ¡°Odd¡± or ¡°Even¡±
thousand©\foot altitudes or flight levels; e.g., 5,000,
6,000, 7,000, FL 250, FL 260, FL 270.
(See ALTITUDE.)
(See FLIGHT LEVEL.)
CARDINAL FLIGHT LEVELS(See CARDINAL ALTITUDES.)
CAT(See CLEAR©\AIR TURBULENCE.)
CATCH POINT- A fix/waypoint that serves as a
transition point from the high altitude waypoint
navigation structure to an arrival procedure (STAR)
or the low altitude ground-based navigation
structure.
CEILING- The heights above the earth's surface of
the lowest layer of clouds or obscuring phenomena
that is reported as ¡°broken, ¡± ¡°overcast,¡± or
¡°obscuration,¡± and not classified as ¡°thin¡± or
¡°partial.¡±
(See ICAO term CEILING.)
CEILING [ICAO]- The height above the ground or
water of the base of the lowest layer of cloud below
6,000 meters (20,000 feet) covering more than half
the sky.
CENRAP(See CENTER RADAR ARTS
PRESENTATION/PROCESSING.)
CENRAP©\PLUS(See CENTER RADAR ARTS
PRESENTATION/PROCESSING©\PLUS.)
CENTER(See AIR ROUTE TRAFFIC CONTROL
CENTER.)
CENTER'S AREA- The specified airspace within
which an air route traffic control center (ARTCC)
provides air traffic control and advisory service.
(See AIR ROUTE TRAFFIC CONTROL
CENTER.)
(Refer to AIM.)
CENTER RADAR ARTS PRESENTATION/
PROCESSING- A computer program developed to
provide a back©\up system for airport surveillance
radar in the event of a failure or malfunction. The
program uses air route traffic control center radar for
the processing and presentation of data on the ARTS
IIA or IIIA displays.
CENTER RADAR ARTS PRESENTATION/
PROCESSING©\PLUS- A computer program
developed to provide a back©\up system for airport
surveillance radar in the event of a terminal secondary
radar system failure. The program uses a combination
of Air Route Traffic Control Center Radar and
terminal airport surveillance radar primary targets
displayed simultaneously for the processing and
presentation of data on the ARTS IIA or IIIA
displays.
CENTER TRACON AUTOMATION SYSTEM
(CTAS)- A computerized set of programs designed
to aid Air Route Traffic Control Centers and
TRACONs in the management and control of air
traffic.
CENTER WEATHER ADVISORY- An unsched©\
uled weather advisory issued by Center Weather
Service Unit meteorologists for ATC use to alert
pilots of existing or anticipated adverse weather
conditions within the next 2 hours. A CWA may
modify or redefine a SIGMET.
(See AWW.)
(See AIRMET.)
(See CONVECTIVE SIGMET.)
(See SIGMET.)
(Refer to AIM.)
Pilot/Controller Glossary 2/14/08
PCG C-2
CENTRAL EAST PACIFIC- An organized route
system between the U.S. West Coast and Hawaii.
CEP(See CENTRAL EAST PACIFIC.)
CERAP(See COMBINED CENTER©\RAPCON.)
CERTIFIED TOWER RADAR DISPLAY (CTRD)-
A FAA radar display certified for use in the NAS.
CFR(See CALL FOR RELEASE.)
CHAFF- Thin, narrow metallic reflectors of various
lengths and frequency responses, used to reflect radar
energy. These reflectors when dropped from aircraft
and allowed to drift downward result in large targets
on the radar display.
CHARTED VFR FLYWAYS- Charted VFR Fly©\
ways are flight paths recommended for use to bypass
areas heavily traversed by large turbine©\powered
aircraft. Pilot compliance with recommended
flyways and associated altitudes is strictly voluntary.
VFR Flyway Planning charts are published on the
back of existing VFR Terminal Area charts.
CHARTED VISUAL FLIGHT PROCEDURE
APPROACH- An approach conducted while
operating on an instrument flight rules (IFR) flight
plan which authorizes the pilot of an aircraft to
proceed visually and clear of clouds to the airport via
visual landmarks and other information depicted on
a charted visual flight procedure. This approach must
be authorized and under the control of the appropriate
air traffic control facility. Weather minimums
required are depicted on the chart.
CHASE- An aircraft flown in proximity to another
aircraft normally to observe its performance during
training or testing.
CHASE AIRCRAFT(See CHASE.)
CIRCLE©\TO©\LAND MANEUVER- A maneuver
initiated by the pilot to align the aircraft with a
runway for landing when a straight©\in landing from
an instrument approach is not possible or is not
desirable. At tower controlled airports, this maneuver
is made only after ATC authorization has been
obtained and the pilot has established required visual
reference to the airport.
(See CIRCLE TO RUNWAY.)
(See LANDING MINIMUMS.)
(Refer to AIM.)
CIRCLE TO RUNWAY (RUNWAY NUMBER)-
Used by ATC to inform the pilot that he/she must
circle to land because the runway in use is other than
the runway aligned with the instrument approach
procedure. When the direction of the circling
maneuver in relation to the airport/runway is
required, the controller will state the direction (eight
cardinal compass points) and specify a left or right
downwind or base leg as appropriate; e.g., ¡°Cleared
VOR Runway Three Six Approach circle to Runway
Two Two,¡± or ¡°Circle northwest of the airport for a
right downwind to Runway Two Two.¡±
(See CIRCLE©\TO©\LAND MANEUVER.)
(See LANDING MINIMUMS.)
(Refer to AIM.)
CIRCLING APPROACH(See CIRCLE©\TO©\LAND MANEUVER.)
CIRCLING MANEUVER(See CIRCLE©\TO©\LAND MANEUVER.)
CIRCLING MINIMA(See LANDING MINIMUMS.)
CLASS A AIRSPACE(See CONTROLLED AIRSPACE.)
CLASS B AIRSPACE(See CONTROLLED AIRSPACE.)
CLASS C AIRSPACE(See CONTROLLED AIRSPACE.)
CLASS D AIRSPACE(See CONTROLLED AIRSPACE.)
CLASS E AIRSPACE(See CONTROLLED AIRSPACE.)
CLASS G AIRSPACE- That airspace not designated
as Class A, B, C, D or E.
CLEAR AIR TURBULENCE (CAT)- Turbulence
encountered in air where no clouds are present. This
term is commonly applied to high©\level turbulence
associated with wind shear. CAT is often encountered
in the vicinity of the jet stream.
(See WIND SHEAR.)
(See JET STREAM.)
CLEAR OF THE RUNWAYa. Taxiing aircraft, which is approaching a
runway, is clear of the runway when all parts of the
Pilot/Controller Glossary 2/14/08
PCG C-3
aircraft are held short of the applicable runway
holding position marking.
b. A pilot or controller may consider an aircraft,
which is exiting or crossing a runway, to be clear of
the runway when all parts of the aircraft are beyond
the runway edge and there are no restrictions to its
continued movement beyond the applicable runway
holding position marking.
c. ilots and controllers shall exercise good
judgement to ensure that adequate separation exists
between all aircraft on runways and taxiways at
airports with inadequate runway edge lines or
holding position markings.
CLEARANCE(See AIR TRAFFIC CLEARANCE.)
CLEARANCE LIMIT- The fix, point, or location to
which an aircraft is cleared when issued an air traffic
clearance.
(See ICAO term CLEARANCE LIMIT.)
CLEARANCE LIMIT [ICAO]- The point of which
an aircraft is granted an air traffic control clearance.
CLEARANCE VOID IF NOT OFF BY (TIME)-
Used by ATC to advise an aircraft that the departure
clearance is automatically canceled if takeoff is not
made prior to a specified time. The pilot must obtain
a new clearance or cancel his/her IFR flight plan if not
off by the specified time.
(See ICAO term CLEARANCE VOID TIME.)
CLEARANCE VOID TIME [IC AO]- A time
specified by an air traffic control unit at which a
clearance ceases to be valid unless the aircraft
concerned has already taken action to comply
therewith.
CLEARED APPROACH- ATC authorization for an
aircraft to execute any standard or special instrument
approach procedure for that airport. Normally, an
aircraft will be cleared for a specific instrument
approach procedure.
(See CLEARED (Type of) APPROACH.)
(See INSTRUMENT APPROACH
PROCEDURE.)
(Refer to 14 CFR Part 91.)
(Refer to AIM.)
CLEARED (Type of) APPROACH- ATC authoriza©\
tion for an aircraft to execute a specific instrument
approach procedure to an airport; e.g., ¡°Cleared ILS
Runway Three Six Approach.¡±
(See APPROACH CLEARANCE.)
(See INSTRUMENT APPROACH
PROCEDURE.)
(Refer to 14 CFR Part 91.)
(Refer to AIM.)
CLEARED AS FILED- Means the aircraft is cleared
to proceed in accordance with the route of flight filed
in the flight plan. This clearance does not include the
altitude, DP, or DP Transition.
(See REQUEST FULL ROUTE CLEARANCE.)
(Refer to AIM.)
CLEARED FOR TAKEOFF- ATC authorization
for an aircraft to depart. It is predicated on known
traffic and known physical airport conditions.
CLEARED FOR THE OPTION- ATC authoriza©\
tion for an aircraft to make a touch©\and©\go, low
approach, missed approach, stop and go, or full stop
landing at the discretion of the pilot. It is normally
used in training so that an instructor can evaluate a
student's performance under changing situations.
(See OPTION APPROACH.)
(Refer to AIM.)
CLEARED THROUGH- ATC authorization for an
aircraft to make intermediate stops at specified
airports without refiling a flight plan while en route
to the clearance limit.
CLEARED TO LAND- ATC authorization for an
aircraft to land. It is predicated on known traffic and
known physical airport conditions.
CLEARWAY- An area beyond the takeoff runway
under the control of airport authorities within which
terrain or fixed obstacles may not extend above
specified limits. These areas may be required for
certain turbine©\powered operations and the size and
upward slope of the clearway will differ depending on
when the aircraft was certificated.
(Refer to 14 CFR Part 1.)
CLIMB TO VFR- ATC authorization for an aircraft
to climb to VFR conditions within Class B, C, D, and
E surface areas when the only weather limitation is
restricted visibility. The aircraft must remain clear of
clouds while climbing to VFR.
(See SPECIAL VFR CONDITIONS.)
(Refer to AIM.)
CLIMBOUT- That portion of flight operation
between takeoff and the initial cruising altitude.
Pilot/Controller Glossary 2/14/08
PCG C-4
CLOSE PARALLEL RUNWAYS- Two parallel
runways whose extended centerlines are separated by
less than 4,300 feet, having a Precision Runway
Monitoring (PRM) system that permits simultaneous
independent ILS approaches.
CLOSED RUNWAY- A runway that is unusable for
aircraft operations. Only the airport management/
military operations office can close a runway.
CLOSED TRAFFIC- Successive operations involv©\
ing takeoffs and landings or low approaches where
the aircraft does not exit the traffic pattern.
CLOUD- A cloud is a visible accumulation of
minute water droplets and/or ice particles in the
atmosphere above the Earth's surface. Cloud differs
from ground fog, fog, or ice fog only in that the latter
are, by definition, in contact with the Earth's surface.
CLT(See CALCULATED LANDING TIME.)
CLUTTER- In radar operations, clutter refers to the
reception and visual display of radar returns caused
by precipitation, chaff, terrain, numerous aircraft
targets, or other phenomena. Such returns may limit
or preclude ATC from providing services based on
radar.
(See CHAFF.)
(See GROUND CLUTTER.)
(See PRECIPITATION.)
(See TARGET.)
(See ICAO term RADAR CLUTTER.)
CMNPS(See CANADIAN MINIMUM NAVIGATION
PERFORMANCE SPECIFICATION AIRSPACE.)
COASTAL FIX- A navigation aid or intersection
where an aircraft transitions between the domestic
route structure and the oceanic route structure.
CODES- The number assigned to a particular
multiple pulse reply signal transmitted by a
transponder.
(See DISCRETE CODE.)
COMBINED CENTER©\RAPCON- An air traffic
facility which combines the functions of an ARTCC
and a radar approach control facility.
(See AIR ROUTE TRAFFIC CONTROL
CENTER.)
(See RADAR APPROACH CONTROL
FACILITY.)
COMMON POINT- A significant point over which
two or more aircraft will report passing or have
reported passing before proceeding on the same or
diverging tracks. To establish/maintain longitudinal
separation, a controller may determine a common
point not originally in the aircraft's flight plan and
then clear the aircraft to fly over the point.
(See SIGNIFICANT POINT.)
COMMON PORTION(See COMMON ROUTE.)
COMMON ROUTE- That segment of a North
American Route between the inland navigation
facility and the coastal fix.
OR
COMMON ROUTE- Typically the portion of a
RNAV STAR between the en route transition end
point and the runway transition start point; however,
the common route may only consist of a single point
that joins the en route and runway transitions.
COMMON TRAFFIC ADVISORY FREQUENCY
(CTAF)- A frequency designed for the purpose of
carrying out airport advisory practices while
operating to or from an airport without an operating
control tower. The CTAF may be a UNICOM,
Multicom, FSS, or tower frequency and is identified
in appropriate aeronautical publications.
(Refer to AC 90©\42, Traffic Advisory Practices at
Airports Without Operating Control Towers.)
COMPASS LOCATOR- A low power, low or
medium frequency (L/MF) radio beacon installed at
the site of the outer or middle marker of an instrument
landing system (ILS). It can be used for navigation at
distances of approximately 15 miles or as authorized
in the approach procedure.
a. Outer Compass Locator (LOM)- A compass
locator installed at the site of the outer marker of an
instrument landing system.
(See OUTER MARKER.)
b. Middle Compass Locator (LMM)- A compass
locator installed at the site of the middle marker of an
instrument landing system.
(See MIDDLE MARKER.)
(See ICAO term LOCATOR.)
COMPASS ROSE- A circle, graduated in degrees,
printed on some charts or marked on the ground at an
airport. It is used as a reference to either true or
magnetic direction.
COMPLY WITH RESTRIC TIONS - An ATC
instruction that requires an aircraft being vectored
Pilot/Controller Glossary 2/14/08
PCG C-5
back onto an arrival or departure procedure to comply
with all altitude and/or speed restrictions depicted on
the procedure. This term may be used in lieu of
repeating each remaining restriction that appears on
the procedure.
COMPOSITE FLIGHT PLAN- A flight plan which
specifies VFR operation for one portion of flight and
IFR for another portion. It is used primarily in
military operations.
(Refer to AIM.)
COMPOSITE ROUTE SYSTEM- An organized
oceanic route structure, incorporating reduced lateral
spacing between routes, in which composite
separation is authorized.
COMPOSITE SEPARATION- A method of separat©\
ing aircraft in a composite route system where, by
management of route and altitude assignments, a
combination of half the lateral minimum specified for
the area concerned and half the vertical minimum is
applied.
COMPULSORY REPORTING POINTS- Reporting
points which must be reported to ATC. They are
designated on aeronautical charts by solid triangles or
filed in a flight plan as fixes selected to define direct
routes. These points are geographical locations
which are defined by navigation aids/fixes. Pilots
should discontinue position reporting over compul©\
sory reporting points when informed by ATC that
their aircraft is in ¡°radar contact.¡±
CONFLICT ALERT- A function of certain air traffic
control automated systems designed to alert radar
controllers to existing or pending situations between
tracked targets (known IFR or VFR aircraft) that
require his/her immediate attention/action.
(See MODE C INTRUDER ALERT.)
CONFLICT RESOLUTION- The resolution of
potential conflictions between aircraft that are radar
identified and in communication with ATC by
ensuring that radar targets do not touch. Pertinent
traffic advisories shall be issued when this procedure
is applied.
Note:This procedure shall not be provided utilizing
mosaic radar systems.
CONFORMANCE- The condition established when
an aircraft's actual position is within the conformance
region constructed around that aircraft at its position,
according to the trajectory associated with the
aircraft's Current Plan.
CONFORMANCE REGION- A volume, bounded
laterally, vertically, and longitudinally, within which
an aircraft must be at a given time in order to be in
conformance with the Current Plan Trajectory for that
aircraft. At a given time, the conformance region is
determined by the simultaneous application of the
lateral, vertical, and longitudinal conformance
bounds for the aircraft at the position defined by time
and aircraft's trajectory.
CONSOLAN- A low frequency, long©\distance
NAVAID used principally for transoceanic naviga©\
tions.
CONTACTa. Establish communication with (followed by the
name of the facility and, if appropriate, the frequency
to be used).
b. A flight condition wherein the pilot ascertains
the attitude of his/her aircraft and navigates by visual
reference to the surface.
(See CONTACT APPROACH.)
(See RADAR CONTACT.)
CONTACT APPROACH- An approach wherein an
aircraft on an IFR flight plan, having an air traffic
control authorization, operating clear of clouds with
at least 1 mile flight visibility and a reasonable
expectation of continuing to the destination airport in
those conditions, may deviate from the instrument
approach procedure and proceed to the destination
airport by visual reference to the surface. This
approach will only be authorized when requested by
the pilot and the reported ground visibility at the
destination airport is at least 1 statute mile.
(Refer to AIM.)
CONTAMINATED RUNWAY- A runway is
considered contaminated whenever standing water,
ice, snow, slush, frost in any form, heavy rubber, or
other substances are present. A runway is contami©\
nated with respect to rubber deposits or other
friction©\degrading substances when the average
friction value for any 500©\foot segment of the runway
within the ALD fails below the recommended
minimum friction level and the average friction value
in the adjacent 500©\foot segments falls below the
maintenance planning friction level.
CONTERMINOUS U.S.- The 48 adjoining States
and the District of Columbia.
Pilot/Controller Glossary 2/14/08
PCG C-6
CONTINENTAL UNITED STATES- The 49 States
located on the continent of North America and the
District of Columbia.
CONTINUE- When used as a control instruction
should be followed by another word or words
clarifying what is expected of the pilot. Example:
¡°continue taxi,¡± ¡°continue descent,¡± ¡°continue
inbound,¡± etc.
CONTROL AREA [ICAO]- A controlled airspace
extending upwards from a specified limit above the
earth.
CONTROL SECTOR- An airspace area of defined
horizontal and vertical dimensions for which a
controller or group of controllers has air traffic
control responsibility, normally within an air route
traffic control center or an approach control facility.
Sectors are established based on predominant traffic
flows, altitude strata, and controller workload.
Pilot©\communications during operations within a
sector are normally maintained on discrete frequen©\
cies assigned to the sector.
(See DISCRETE FREQUENCY.)
CONTROL SLASH- A radar beacon slash repre©\
senting the actual position of the associated aircraft.
Normally, the control slash is the one closest to the
interrogating radar beacon site. When ARTCC radar
is operating in narrowband (digitized) mode, the
control slash is converted to a target symbol.
CONTROLLED AIR SPACE- An airspace of
defined dimensions within which air traffic control
service is provided to IFR flights and to VFR flights
in accordance with the airspace classification.
a. Controlled airspace is a generic term that covers
Class A, Class B, Class C, Class D, and Class E
airspace.
b. Controlled airspace is also that airspace within
which all aircraft operators are subject to certain pilot
qualifications, operating rules, and equipment
requirem ents in 14 CFR Part 91 (for specific
operating requirements, please refer to 14 CFR
Part 91). For IFR operations in any class of controlled
airspace, a pilot must file an IFR flight plan and
receive an appropriate ATC clearance. Each Class B,
Class C, and Class D airspace area designated for an
airport contains at least one primary airport around
which the airspace is designated (for specific
designations and descriptions of the airspace classes,
please refer to 14 CFR Part 71).
c. Controlled airspace in the United States is
designated as follows:
1. CLASS A- Generally, that airspace from
18,000 feet MSL up to and including FL 600,
including the airspace overlying the waters within 12
nautical miles of the coast of the 48 contiguous States
and Alaska. Unless otherwise authorized, all persons
must operate their aircraft under IFR.
2. CLASS B- Generally, that airspace from the
surface to 10,000 feet MSL surrounding the nation's
busiest airports in terms of airport operations or
passenger enplanements. The configuration of each
Class B airspace area is individually tailored and
consists of a surface area and two or more layers
(some Class B airspaces areas resemble upside©\down
wedding cakes), and is designed to contain all
published instrument procedures once an aircraft
enters the airspace. An ATC clearance is required for
all aircraft to operate in the area, and all aircraft that
are so cleared receive separation services within the
airspace. The cloud clearance requirement for VFR
operations is ¡°clear of clouds.¡±
3. CLASS C- Generally, that airspace from the
surface to 4,000 feet above the airport elevation
(charted in MSL) surrounding those airports that
have an operational control tower, are serviced by a
radar approach control, and that have a certain
number of IFR operations or passenger enplane©\
ments. Although the configuration of each Class C
area is individually tailored, the airspace usually
consists of a surface area with a 5 nautical mile (NM)
radius, a circle with a 10NM radius that extends no
lower than 1,200 feet up to 4,000 feet above the
airport elevation and an outer area that is not charted.
Each person must establish two©\way radio commu©\
nications with the ATC facility providing air traffic
services prior to entering the airspace and thereafter
maintain those communications while within the
airspace. VFR aircraft are only separated from IFR
aircraft within the airspace.
(See OUTER AREA.)
4. CLASS D- Generally, that airspace from the
surface to 2,500 feet above the airport elevation
(charted in MSL) surrounding those airports that
have an operational control tower. The configuration
of each Class D airspace area is individually tailored
and when instrument procedures are published, the
airspace will normally be designed to contain the
procedures. Arrival extensions for instrument
approach procedures may be Class D or Class E
Pilot/Controller Glossary 2/14/08
PCG C-7
airspace. Unless otherwise authorized, each person
must establish two©\way radio communications with
the ATC facility providing air traffic services prior to
entering the airspace and thereafter maintain those
communications while in the airspace. No separation
services are provided to VFR aircraft.
5. CLASS E- Generally, if the airspace is not
Class A, Class B, Class C, or Class D, and it is
controlled airspace, it is Class E airspace. Class E
airspace extends upward from either the surface or a
designated altitude to the overlying or adjacent
controlled airspace. When designated as a surface
area, the airspace will be configured to contain all
instrument procedures. Also in this class are Federal
airways, airspace beginning at either 700 or 1,200
feet AGL used to transition to/from the terminal or en
route environment, en route domestic, and offshore
airspace areas designated below 18,000 feet MSL.
Unless designated at a lower altitude, Class E
airspace begins at 14,500 MSL over the United
States, including that airspace overlying the waters
within 12 nautical miles of the coast of the 48
contiguous States and Alaska, up to, but not
including 18,000 feet MSL, and the airspace above
FL 600.
CONTROLLED AIRSPACE [ICAO]- An airspace
of defined dimensions within which air traffic control
service is provided to IFR flights and to VFR flights
in accordance with the airspace classification.
Note:Controlled airspace is a generic term which
covers ATS airspace Classes A, B, C, D, and E.
CONTROLLED TIME OF ARRIVAL- Arrival time
assigned during a Traffic Management Program. This
time may be modified due to adjustments or user
options.
CONTROLLER(See AIR TRAFFIC CONTROL SPECIALIST.)
CONTROLLER [ICAO]- A person authorized to
provide air traffic control services.
CONTROLLER PILOT DATA LINK COMMU©\
NICATIONS (CPDLC)- A two-way digital very
high frequency (VHF) air/ground communications
system that conveys textual air traffic control
messages between controllers and pilots.
CONVECTIVE SIGMET- A weather advisory
concerning convective weather significant to the
safety of all aircraft. Convective SIGMETs are issued
for tornadoes, lines of thunderstorms, embedded
thunderstorms of any intensity level, areas of
thunderstorms greater than or equal to VIP level 4
with an area coverage of 4
/10 (40%) or more, and hail
3
/4 inch or greater.
(See AIRMET.)
(See AWW.)
(See CWA.)
(See SIGMET.)
(Refer to AIM.)
CONVECTIVE SIGNIFICANT METEOROLOG©\
ICAL INFORMATION(See CONVECTIVE SIGMET.)
COORDINATES- The intersection of lines of
reference, usually expressed in degrees/minutes/
seconds of latitude and longitude, used to determine
position or location.
COORDINATION FIX- The fix in relation to which
facilities will handoff, transfer control of an aircraft,
or coordinate flight progress data. For terminal
facilities, it may also serve as a clearance for arriving
aircraft.
COPTER(See HELICOPTER.)
CORRECTION- An error has been made in the
transmission and the correct version follows.
COUPLED APPROACH- A coupled approach is an
instrument approach performed by the aircraft
autopilot which is receiving position information
and/or steering commands from onboard navigation
equipment. In general, coupled nonprecision ap©\
proaches must be discontinued and flown manually
at altitudes lower than 50 feet below the minimum
descent altitude, and coupled precision approaches
must be flown manually below 50 feet AGL.
Note:Coupled and autoland approaches are flown
in VFR and IFR. It is common for carriers to require
their crews to fly coupled approaches and autoland
approaches (if certified) when the weather
conditions are less than approximately 4,000 RVR.
(See AUTOLAND APPROACH.)
COURSEa. The intended direction of flight in the horizontal
plane measured in degrees from north.
b. The ILS localizer signal pattern usually
specified as the front course or the back course.
Pilot/Controller Glossary 2/14/08
PCG C-8
c. The intended track along a straight, curved, or
segmented MLS path.
(See BEARING.)
(See INSTRUMENT LANDING SYSTEM.)
(See MICROWAVE LANDING SYSTEM.)
(See RADIAL.)
CPDLC(See CONTROLLER PILOT DATA LINK
COMMUNICATIONS.)
CPL [ICAO]-
(See ICAO term CURRENT FLIGHT PLAN.)
CRITICAL ENGINE- The engine which, upon
failure, would most adversely affect the performance
or handling qualities of an aircraft.
CROSS (FIX) AT (ALTITUDE)- Used by ATC
when a specific altitude restriction at a specified fix
is required.
CROSS (FIX) AT OR ABOVE (ALTITUDE)- Used
by ATC when an altitude restriction at a specified fix
is required. It does not prohibit the aircraft from
crossing the fix at a higher altitude than specified;
however, the higher altitude may not be one that will
violate a succeeding altitude restriction or altitude
assignment.
(See ALTITUDE RESTRICTION.)
(Refer to AIM.)
CROSS (FIX) AT OR BELOW (ALTITUDE)-
Used by ATC when a maximum crossing altitude at
a specific fix is required. It does not prohibit the
aircraft from crossing the fix at a lower altitude;
however, it must be at or above the minimum IFR
altitude.
(See ALTITUDE RESTRICTION.)
(See MINIMUM IFR ALTITUDES.)
(Refer to 14 CFR Part 91.)
CROSSWINDa. When used concerning the traffic pattern, the
word means ¡°crosswind leg.¡±
(See TRAFFIC PATTERN.)
b. When used concerning wind conditions, the
word means a wind not parallel to the runway or the
path of an aircraft.
(See CROSSWIND COMPONENT.)
CROSSWIND COMPONENT- The wind compo©\
nent measured in knots at 90 degrees to the
longitudinal axis of the runway.
CRUISE- Used in an ATC clearance to authorize a
pilot to conduct flight at any altitude from the
minimum IFR altitude up to and including the
altitude specified in the clearance. The pilot may
level off at any intermediate altitude within this block
of airspace. Climb/descent within the block is to be
made at the discretion of the pilot. However, once the
pilot starts descent and verbally reports leaving an
altitude in the block, he/she may not return to that
altitude without additional ATC clearance. Further, it
is approval for the pilot to proceed to and make an
approach at destination airport and can be used in
conjunction with:
a. An airport clearance limit at locations with a
standard/special instrument approach procedure. The
CFRs require that if an instrument letdown to an
airport is necessary, the pilot shall make the letdown
in accordance with a standard/special instrument
approach procedure for that airport, or
b. An airport clearance limit at locations that are
within/below/outside controlled airspace and with©\
out a standard/special instrument approach
procedure. Such a clearance is NOT AUTHORIZA©\
TION for the pilot to descend under IFR conditions
below the applicable minimum IFR altitude nor does
it imply that ATC is exercising control over aircraft
in Class G airspace; however, it provides a means for
the aircraft to proceed to destination airport, descend,
and land in accordance with applicable CFRs
governing VFR flight operations. Also, this provides
search and rescue protection until such time as the
IFR flight plan is closed.
(See INSTRUMENT APPROACH
PROCEDURE.)
CRUISE CLIMB- A climb technique employed by
aircraft, usually at a constant power setting, resulting
in an increase of altitude as the aircraft weight
decreases.
CRUISING ALTITUDE- An altitude or flight level
maintained during en route level flight. This is a
constant altitude and should not be confused with a
cruise clearance.
(See ALTITUDE.)
(See ICAO term CRUISING LEVEL.)
CRUISING LEVEL(See CRUISING ALTITUDE.)
CRUISING LEVEL [ICAO]- A level maintained
during a significant portion of a flight.
Pilot/Controller Glossary 2/14/08
PCG C-9
CT MESSAGE- An EDCT time generated by the
ATCSCC to regulate traffic at arrival airports.
Normally, a CT message is automatically transferred
from the Traffic Management System computer to the
NAS en route computer and appears as an EDCT. In
the event of a communication failure between the
TMS and the NAS, the CT message can be manually
entered by the TMC at the en route facility.
CTA(See CONTROLLED TIME OF ARRIVAL.)
(See ICAO term CONTROL AREA.)
CTAF(See COMMON TRAFFIC ADVISORY
FREQUENCY.)
CTAS(See CENTER TRACON AUTOMATION
SYSTEM.)
CTRD(See CERTIFIED TOWER RADAR DISPLAY.)
CURRENT FLIGHT PLAN [ICAO]- The flight
plan, including changes, if any, brought about by
subsequent clearances.
CURRENT PLAN- The ATC clearance the aircraft
has received and is expected to fly.
CVFP APPROACH(See CHARTED VISUAL FLIGHT PROCEDURE
APPROACH.)
CWA(See CENTER WEATHER ADVISORY and
WEATHER ADVISORY.)
Pilot/Controller Glossary 2/14/08
PCG D-1
D
D©\ATIS(See DIGITAL©\AUTOMATIC TERMINAL
INFORMATION SERVICE.)
DA [ICAO]-
(See ICAO Term DECISION
ALTITUDE/DECISION HEIGHT.)
DAIR(See DIRECT ALTITUDE AND IDENTITY
READOUT.)
DANGER AREA [ICAO]- An airspace of defined
dimensions within which activities dangerous to the
flight of aircraft may exist at specified times.
Note:The term ¡°Danger Area¡± is not used in
reference to areas within the United States or any
of its possessions or territories.
DAS(See DELAY ASSIGNMENT.)
DATA BLOCK(See ALPHANUMERIC DISPLAY.)
DEAD RECKONING- Dead reckoning, as applied
to flying, is the navigation of an airplane solely by
means of computations based on airspeed, course,
heading, wind direction, and speed, groundspeed,
and elapsed time.
DECIS ION ALTITUDE/DECIS ION HEIGHT
[ICAO]- A specified altitude or height (A/H) in the
precision approach at which a missed approach must
be initiated if the required visual reference to
continue the approach has not been established.
Note 1:Decision altitude [DA] is referenced to
mean sea level [MSL] and decision height [DH] is
referenced to the threshold elevation.
Note 2:The required visual reference means that
section of the visual aids or of the approach area
which should have been in view for sufficient time
for the pilot to have made an assessment of the
aircraft position and rate of change of position, in
relation to the desired flight path.
DECISION HEIGHT- With respect to the operation
of aircraft, means the height at which a decision must
be made during an ILS, MLS, or PAR instrument
approach to either continue the approach or to execute
a missed approach.
(See ICAO term DECISION
ALTITUDE/DECISION HEIGHT.)
DECODER- The device used to decipher signals
received from ATCRBS transponders to effect their
display as select codes.
(See CODES.)
(See RADAR.)
DEFENSE VIS UAL FLIGHT RULES- Rules
applicable to flights within an ADIZ conducted under
the visual flight rules in 14 CFR Part 91.
(See AIR DEFENSE IDENTIFICATION ZONE.)
(Refer to 14 CFR Part 91.)
(Refer to 14 CFR Part 99.)
DELAY ASSIGNMENT (DAS)- Delays are distrib©\
uted to aircraft based on the traffic management
program parameters. The delay assignment is
calculated in 15-minute increments and appears as a
table in Enhanced Traffic Management System
(ETMS).
DELAY INDEFINITE (REASON IF KNOWN)
EXPECT FURTHER CLEARANCE (TIME)- Used
by ATC to inform a pilot when an accurate estimate
of the delay time and the reason for the delay cannot
immediately be determined; e.g., a disabled aircraft
on the runway, terminal or center area saturation,
weather below landing minimums, etc.
(See EXPECT FURTHER CLEARANCE (TIME).)
DELAY TIME- The amount of time that the arrival
must lose to cross the meter fix at the assigned meter
fix time. This is the difference between ACLT and
VTA.
DEPARTURE CENTER- The ARTCC having
jurisdiction for the airspace that generates a flight to
the impacted airport.
DEPARTURE CONTROL- A function of an
approach control facility providing air traffic control
service for departing IFR and, under certain
conditions, VFR aircraft.
(See APPROACH CONTROL FACILITY.)
(Refer to AIM.)
DEPARTURE SEQUENCING PROGRAM- A
program designed to assist in achieving a specified
interval over a common point for departures.
Pilot/Controller Glossary 2/14/08
PCG D-2
DEPARTURE TIME- The time an aircraft becomes
airborne.
DESCENT SPEED ADJUSTMENTS- Speed decel©\
eration calculations made to determine an accurate
VTA. These calculations start at the transition point
and use arrival speed segments to the vertex.
DESIRED COURSEa. True- A predetermined desired course direction
to be followed (measured in degrees from true north).
b. Magnetic- A predetermined desired course
direction to be followed (measured in degrees from
local magnetic north).
DESIRED TRACK- The planned or intended track
between two waypoints. It is measured in degrees
from either magnetic or true north. The instantaneous
angle may change from point to point along the great
circle track between waypoints.
DETRESFA (DISTRESS PHASE) [ICAO]- The
code word used to designate an emergency phase
wherein there is reasonable certainty that an aircraft
and its occupants are threatened by grave and
imminent danger or require immediate assistance.
DEVIATIONSa. A departure from a current clearance, such as an
off course maneuver to avoid weather or turbulence.
b. Where specifically authorized in the CFRs and
requested by the pilot, ATC may permit pilots to
deviate from certain regulations.
(Refer to AIM.)
DF(See DIRECTION FINDER.)
DF APPROACH PROCEDURE- Used under
emergency conditions where another instrument
approach procedure cannot be executed. DF guidance
for an instrument approach is given by ATC facilities
with DF capability.
(See DF GUIDANCE.)
(See DIRECTION FINDER.)
(Refer to AIM.)
DF FIX- The geographical location of an aircraft
obtained by one or more direction finders.
(See DIRECTION FINDER.)
DF GUIDANCE- Headings provided to aircraft by
facilities equipped with direction finding equipment.
These headings, if followed, will lead the aircraft to
a predetermined point such as the DF station or an
airport. DF guidance is given to aircraft in distress or
to other aircraft which request the service. Practice
DF guidance is provided when workload permits.
(See DIRECTION FINDER.)
(See DF FIX.)
(Refer to AIM.)
DF STEER(See DF GUIDANCE.)
DH(See DECISION HEIGHT.)
DH [ICAO]-
(See ICAO Term DECISION ALTITUDE/
DECISION HEIGHT.)
DIGITAL©\AUTOMATIC TERMINAL INFORMA©\
TION SERVICE (D©\ATIS)- The service provides
text messages to aircraft, airlines, and other users
outside the standard reception range of conventional
ATIS via landline and data link communications to
the cockpit. Also, the service provides a computersynthesized voice message that can be transmitted to
all aircraft within range of existing transmitters. The
Term inal Data Link System (TDLS) D©\ATIS
application uses weather inputs from local automated
weather sources or manually entered meteorological
data together with preprogrammed menus to provide
standard information to users. Airports with D©\ATIS
capability are listed in the Airport/Facility Directory.
DIGITAL TARGET- A computer-generated symbol
representing an aircraft's position, based on a primary
return or radar beacon reply, shown on a digital
display.
DIGITAL TERMINAL AUTOMATION SYSTEM
(DTAS)- A system where digital radar and beacon
data is presented on digital displays and the
operational program monitors the system perfor©\
mance on a real-time basis.
DIGITIZED TARGET- A computer-generated
indication shown on an analog radar display resulting
from a primary radar return or a radar beacon reply.
DIRECT- Straight line flight between two naviga©\
tional aids, fixes, points, or any combination thereof.
When used by pilots in describing off©\airway routes,
points defining direct route segments become
compulsory reporting points unless the aircraft is
under radar contact.
DIRECT ALTITUDE AND IDENTITY READ©\
OUT- The DAIR System is a modification to the
Pilot/Controller Glossary 2/14/08
PCG D-3
AN/TPX©\42 Interrogator System. The Navy has two
adaptations of the DAIR System©\Carrier Air Traffic
Control Direct Altitude and Identification Readout
System for Aircraft Carriers and Radar Air Traffic
Control Facility Direct Altitude and Identity Readout
System for land©\based terminal operations. The
DAIR detects, tracks, and predicts secondary radar
aircraft targets. Targets are displayed by means of
computer©\generated symbols and alphanumeric
characters depicting flight identification, altitude,
ground speed, and flight plan data. The DAIR System
is capable of interfacing with ARTCCs.
DIRECTION FINDER- A radio receiver equipped
with a directional sensing antenna used to take
bearings on a radio transmitter. Specialized radio
direction finders are used in aircraft as air navigation
aids. Others are ground©\based, primarily to obtain a
¡°fix¡± on a pilot requesting orientation assistance or to
locate downed aircraft. A location ¡°fix¡± is established
by the intersection of two or more bearing lines
plotted on a navigational chart using either two
separately located Direction Finders to obtain a fix on
an aircraft or by a pilot plotting the bearing
indications of his/her DF on two separately located
ground©\based transmitters, both of which can be
identified on his/her chart. UDFs receive signals in
the ultra high frequency radio broadcast band; VDFs
in the very high frequency band; and UVDFs in both
bands. ATC provides DF service at those air traffic
control towers and flight service stations listed in the
Airport/Facility Directory and the DOD FLIP IFR En
Route Supplement.
(See DF FIX.)
(See DF GUIDANCE.)
DIRECTLY BEHIND- An aircraft is considered to
be operating directly behind when it is following the
actual flight path of the lead aircraft over the surface
of the earth except when applying wake turbulence
separation criteria.
DISCRETE BEACON CODE(See DISCRETE CODE.)
DISCRETE CODE- As used in the Air Traffic
Control Radar Beacon System (ATCRBS), any one
of the 4096 selectable Mode 3/A aircraft transponder
codes except those ending in zero zero; e.g., discrete
codes: 0010, 1201, 2317, 7777; nondiscrete codes:
0100, 1200, 7700. Nondiscrete codes are normally
reserved for radar facilities that are not equipped with
discrete decoding capability and for other purposes
such as emergencies (7700), VFR aircraft (1200), etc.
(See RADAR.)
(Refer to AIM.)
DIS CRETE FREQUENCY- A separate radio
frequency for use in direct pilot©\controller commu©\
nications in air traffic control which reduces
frequency congestion by controlling the number of
aircraft operating on a particular frequency at one
time. Discrete frequencies are normally designated
for each control sector in en route/terminal ATC
facilities. Discrete frequencies are listed in the
Airport/Facility Directory and the DOD FLIP IFR En
Route Supplement.
(See CONTROL SECTOR.)
DISPLACED THRESHOLD- A threshold that is
located at a point on the runway other than the
designated beginning of the runway.
(See THRESHOLD.)
(Refer to AIM.)
DISTANCE MEASURING EQUIPMENT- Equip©\
ment (airborne and ground) used to measure, in
nautical miles, the slant range distance of an aircraft
from the DME navigational aid.
(See MICROWAVE LANDING SYSTEM.)
(See TACAN.)
(See VORTAC.)
DISTRESS- A condition of being threatened by
serious and/or imminent danger and of requiring
immediate assistance.
DIVE BRAKES(See SPEED BRAKES.)
DIVERSE VECTOR AREA- In a radar environ©\
ment, that area in which a prescribed departure route
is not required as the only suitable route to avoid
obstacles. The area in which random radar vectors
below the MVA/MIA, established in accordance with
the TERPS criteria for diverse departures, obstacles
and terrain avoidance, may be issued to departing
aircraft.
DIVERSION (DVRSN)- Flights that are required to
land at other than their original destination for
reasons beyond the control of the pilot/company, e.g.
periods of significant weather.
DME(See DISTANCE MEASURING EQUIPMENT.)
Pilot/Controller Glossary 2/14/08
PCG D-4
DME FIX- A geographical position determined by
reference to a navigational aid which provides
distance and azimuth information. It is defined by a
specific distance in nautical miles and a radial,
azimuth, or course (i.e., localizer) in degrees
magnetic from that aid.
(See DISTANCE MEASURING EQUIPMENT.)
(See FIX.)
(See MICROWAVE LANDING SYSTEM.)
DME SEPARATION- Spacing of aircraft in terms of
distances (nautical miles) determined by reference to
distance measuring equipment (DME).
(See DISTANCE MEASURING EQUIPMENT.)
DOD FLIP- Department of Defense Flight Informa©\
tion Publications used for flight planning, en route,
and terminal operations. FLIP is produced by the
National Imagery and Mapping Agency (NIMA) for
world©\wide use. United States Government Flight
Information Publications (en route charts and
instrument approach procedure charts) are incorpo©\
rated in DOD FLIP for use in the National Airspace
System (NAS).
DOMESTIC AIRSPACE- Airspace which overlies
the continental land mass of the United States plus
Hawaii and U.S. possessions. Domestic airspace
extends to 12 miles offshore.
DOWNBURST- A strong downdraft which induces
an outburst of damaging winds on or near the ground.
Damaging winds, either straight or curved, are highly
divergent. The sizes of downbursts vary from 1/2
mile or less to more than 10 miles. An intense
downburst often causes widespread damage. Damag©\
ing winds, lasting 5 to 30 minutes, could reach speeds
as high as 120 knots.
DOWNWIND LEG(See TRAFFIC PATTERN.)
DP(See INSTRUMENT DEPARTURE PROCEDURE.)
DRAG CHUTE- A parachute device installed on
certain aircraft which is deployed on landing roll to
assist in deceleration of the aircraft.
DSP(See DEPARTURE SEQUENCING PROGRAM.)
DT(See DELAY TIME.)
DTAS(See DIGITAL TERMINAL AUTOMATION
SYSTEM.)
DUE REGARD- A phase of flight wherein an
aircraft commander of a State©\operated aircraft
assumes responsibility to separate his/her aircraft
from all other aircraft.
(See also FAAO JO 7110.65, Para 1-2-1, WORD
MEANINGS.)
DUTY RUNWAY(See RUNWAY IN USE/ACTIVE RUNWAY/DUTY
RUNWAY.)
DVA(See DIVERSE VECTOR AREA.)
DVFR(See DEFENSE VISUAL FLIGHT RULES.)
DVFR FLIGHT PLAN- A flight plan filed for a VFR
aircraft which intends to operate in airspace within
which the ready identification, location, and control
of aircraft are required in the interest of national
security.
DVRSN(See DIVERSION.)
DYNAMIC- Continuous review, evaluation, and
change to meet demands.
DYNAMIC RESTRICTIONS- Those restrictions
imposed by the local facility on an ¡°as needed¡± basis
to manage unpredictable fluctuations in traffic
demands.
Pilot/Controller Glossary 2/14/08
PCG E-1
E
EAS(See EN ROUTE AUTOMATION SYSTEM.)
EDCT(See EXPECT DEPARTURE CLEARANCE
TIME.)
EFC(See EXPECT FURTHER CLEARANCE (TIME).)
ELT(See EMERGENCY LOCATOR TRANSMITTER.)
EMERGENCY- A distress or an urgency condition.
EMERGENCY LOCATOR TRANSMITTER- A
radio transmitter attached to the aircraft structure
which operates from its own power source on
121.5 MHz and 243.0 MHz. It aids in locating
downed aircraft by radiating a downward sweeping
audio tone, 2©\4 times per second. It is designed to
function without human action after an accident.
(Refer to 14 CFR Part 91.)
(Refer to AIM.)
E©\MSAW(See EN ROUTE MINIMUM SAFE ALTITUDE
WARNING.)
EN ROUTE AIR TRAFFIC CONTROL SER©\
VICES- Air traffic control service provided aircraft
on IFR flight plans, generally by centers, when these
aircraft are operating between departure and
destination terminal areas. When equipment, capa©\
bilities, and controller workload permit, certain
advisory/assistance services may be provided to VFR
aircraft.
(See AIR ROUTE TRAFFIC CONTROL
CENTER.)
(Refer to AIM.)
EN ROUTE AUTOMATION SYSTEM (EAS)- The
complex integrated environment consisting of
situation display systems, surveillance systems and
flight data processing, remote devices, decision
support tools, and the related communications
equipment that form the heart of the automated IFR
air traffic control system. It interfaces with automated
terminal systems and is used in the control of en route
IFR aircraft.
(Refer to AIM.)
EN ROUTE CHARTS(See AERONAUTICAL CHART.)
EN ROUTE DESCENT- Descent from the en route
cruising altitude which takes place along the route of
flight.
EN ROUTE FLIGHT ADVISORY SERVICE- A
service specifically designed to provide, upon pilot
request, timely weather information pertinent to
his/her type of flight, intended route of flight, and
altitude. The FSSs providing this service are listed in
the Airport/Facility Directory.
(See FLIGHT WATCH.)
(Refer to AIM.)
EN ROUTE HIGH ALTITUDE CHARTS(See AERONAUTICAL CHART.)
EN ROUTE LOW ALTITUDE CHARTS(See AERONAUTICAL CHART.)
EN ROUTE MINIMUM SAFE ALTITUDE WARN©\
ING- A function of the EAS that aids the controller
by providing an alert when a tracked aircraft is below
or predicted by the computer to go below a
predetermined minimum IFR altitude (MIA).
EN ROUTE SPACING PROGRAM (ESP)- A
program designed to assist the exit sector in
achieving the required in©\trail spacing.
EN ROUTE TRANSITIONa. Conventional STARs/SIDs. The portion of a
SID/STAR that connects to one or more en route
airway/jet route.
b. RNAV STARs/SIDs. The portion of a STAR
preceding the common route or point, or for a SID the
portion following, that is coded for a specific en route
fix, airway or jet route.
ESP(See EN ROUTE SPACING PROGRAM.)
ESTABLISHED-To be stable or fixed on a route,
route segment, altitude, heading, etc.
ESTIMATED ELAPSED TIME [IC AO]- The
estimated time required to proceed from one
significant point to another.
(See ICAO Term TOTAL ESTIMATED ELAPSED
TIME.)
Pilot/Controller Glossary 2/14/08
PCG E-2
ESTIMATED OFF©\BLOCK TIME [ICAO]- The
estimated time at which the aircraft will commence
movement associated with departure.
ESTIMATED POSITION ERROR (EPE)-
(See Required Navigation Performance)
ESTIMATED TIME OF ARRIVAL- The time the
flight is estimated to arrive at the gate (scheduled
operators) or the actual runway on times for
nonscheduled operators.
ESTIMATED TIME EN ROUTE- The estimated
flying time from departure point to destination
(lift©\off to touchdown).
ETA(See ESTIMATED TIME OF ARRIVAL.)
ETE(See ESTIMATED TIME EN ROUTE.)
EXECUTE MISSED APPROACH- Instructions
issued to a pilot making an instrument approach
which means continue inbound to the missed
approach point and execute the missed approach
procedure as described on the Instrument Approach
Procedure Chart or as previously assigned by ATC.
The pilot may climb immediately to the altitude
specified in the missed approach procedure upon
making a missed approach. No turns should be
initiated prior to reaching the missed approach point.
When conducting an ASR or PAR approach, execute
the assigned missed approach procedure immediately
upon receiving instructions to ¡°execute missed
approach.¡±
(Refer to AIM.)
EXPECT (ALTITUDE) AT (TIME) or (FIX)- Used
under certain conditions to provide a pilot with an
altitude to be used in the event of two©\way
communications failure. It also provides altitude
information to assist the pilot in planning.
(Refer to AIM.)
EXPECT DEPARTURE CLEARANCE TIME
(EDCT)- The runway release time assigned to an
aircraft in a traffic management program and shown
on the flight progress strip as an EDCT.
(See GROUND DELAY PROGRAM.)
EXPECT FURTHER CLEARANCE (TIME)- The
time a pilot can expect to receive clearance beyond a
clearance limit.
EXPECT FURTHER CLEARANCE VIA (AIR©\
WAYS, ROUTES OR FIXES)- Used to inform a
pilot of the routing he/she can expect if any part of the
route beyond a short range clearance limit differs
from that filed.
EXPEDITE- Used by ATC when prompt com©\
pliance is required to avoid the development of an
imminent situation. Expedite climb/descent normal©\
ly indicates to a pilot that the approximate best rate
of climb/descent should be used without requiring an
exceptional change in aircraft handling characteris©\
tics.
Pilot/Controller Glossary 2/14/08
PCG F-1
F
FAF(See FINAL APPROACH FIX.)
FAST FILE- A system whereby a pilot files a flight
plan via telephone that is tape recorded and then
transcribed for transmission to the appropriate air
traffic facility. Locations having a fast file capability
are contained in the Airport/Facility Directory.
(Refer to AIM.)
FAWP- Final Approach Waypoint
FCLT(See FREEZE CALCULATED LANDING TIME.)
FEATHERED PROPELLER- A propeller whose
blades have been rotated so that the leading and
trailing edges are nearly parallel with the aircraft
flight path to stop or minimize drag and engine
rotation. Normally used to indicate shutdown of a
reciprocating or turboprop engine due to malfunc©\
tion.
FEDERAL AIRWAYS(See LOW ALTITUDE AIRWAY STRUCTURE.)
FEEDER FIX- The fix depicted on Instrument
Approach Procedure Charts which establishes the
starting point of the feeder route.
FEEDER ROUTE- A route depicted on instrument
approach procedure charts to designate routes for
aircraft to proceed from the en route structure to the
initial approach fix (IAF).
(See INSTRUMENT APPROACH
PROCEDURE.)
FERRY FLIGHT- A flight for the purpose of:
a. Returning an aircraft to base.
b. Delivering an aircraft from one location to
another.
c. Moving an aircraft to and from a maintenance
base.- Ferry flights, under certain conditions, may be
conducted under terms of a special flight permit.
FIELD ELEVATION(See AIRPORT ELEVATION.)
FILED- Normally used in conjunction with flight
plans, meaning a flight plan has been submitted to
ATC.
FILED EN ROUTE DELAY- Any of the following
preplanned delays at points/areas along the route of
flight which require special flight plan filing and
handling techniques.
a. Terminal Area Delay. A delay within a terminal
area for touch©\and©\go, low approach, or other
terminal area activity.
b. Special Use Airspace Delay. A delay within a
Military Operations Area, Restricted Area, Warning
Area, or ATC Assigned Airspace.
c. Aerial Refueling Delay. A delay within an
Aerial Refueling Track or Anchor.
FILED FLIGHT PLAN- The flight plan as filed with
an ATS unit by the pilot or his/her designated
representative without any subsequent changes or
clearances.
FINAL- Commonly used to mean that an aircraft is
on the final approach course or is aligned with a
landing area.
(See FINAL APPROACH COURSE.)
(See FINAL APPROACH©\IFR.)
(See SEGMENTS OF AN INSTRUMENT
APPROACH PROCEDURE.)
FINAL APPROACH [ICAO]- That part of an
instrument approach procedure which commences at
the specified final approach fix or point, or where
such a fix or point is not specified.
a. At the end of the last procedure turn, base turn
or inbound turn of a racetrack procedure, if specified;
or
b. At the point of interception of the last track
specified in the approach procedure; and ends at a
point in the vicinity of an aerodrome from which:
1. A landing can be made; or
2. A missed approach procedure is initiated.
FINAL APPROACH COURSE- A bearing/radial/
track of an instrument approach leading to a runway
or an extended runway centerline all without regard
to distance.
FINAL APPROACH FIX- The fix from which the
final approach (IFR) to an airport is executed and
which identifies the beginning of the final approach
segment. It is designated on Government charts by
the Maltese Cross symbol for nonprecision
Pilot/Controller Glossary 2/14/08
PCG F-2
approaches and the lightning bolt symbol for
precision approaches; or when ATC directs a
lower©\than©\published glideslope/path intercept alti©\
tude, it is the resultant actual point of the
glideslope/path intercept.
(See FINAL APPROACH POINT.)
(See GLIDESLOPE INTERCEPT ALTITUDE.)
(See SEGMENTS OF AN INSTRUMENT
APPROACH PROCEDURE.)
FINAL APPROACH©\IFR- The flight path of an
aircraft which is inbound to an airport on a final
instrument approach course, beginning at the final
approach fix or point and extending to the airport or
the point where a circle©\to©\land maneuver or a missed
approach is executed.
(See FINAL APPROACH COURSE.)
(See FINAL APPROACH FIX.)
(See FINAL APPROACH POINT.)
(See SEGMENTS OF AN INSTRUMENT
APPROACH PROCEDURE.)
(See ICAO term FINAL APPROACH.)
FINAL APPROACH POINT- The point, applicable
only to a nonprecision approach with no depicted
FAF (such as an on airport VOR), where the aircraft
is established inbound on the final approach course
from the procedure turn and where the final approach
descent may be commenced. The FAP serves as the
FAF and identifies the beginning of the final
approach segment.
(See FINAL APPROACH FIX.)
(See SEGMENTS OF AN INSTRUMENT
APPROACH PROCEDURE.)
FINAL APPROACH SEGMENT(See SEGMENTS OF AN INSTRUMENT
APPROACH PROCEDURE.)
FINAL APPROACH SEGMENT [ICAO]- That
segment of an instrument approach procedure in
which alignment and descent for landing are
accomplished.
FINAL CONTROLLER- The controller providing
information and final approach guidance during PAR
and ASR approaches utilizing radar equipment.
(See RADAR APPROACH.)
FINAL GUARD SERVICE- A value added service
provided in conjunction with LAA/RAA only during
periods of significant and fast changing weather
conditions that may affect landing and takeoff
operations.
FINAL MONITOR AID- A high resolution color
display that is equipped with the controller alert
system hardware/software which is used in the
precision runway monitor (PRM) system. The
display includes alert algorithms providing the target
predictors, a color change alert when a target
penetrates or is predicted to penetrate the no
transgression zone (NTZ), a color change alert if the
aircraft transponder becomes inoperative, synthe©\
sized voice alerts, digital mapping, and like features
contained in the PRM system.
(See RADAR APPROACH.)
FINAL MONITOR CONTROLLER- Air Traffic
Control Specialist assigned to radar monitor the
flight path of aircraft during simultaneous parallel
and simultaneous close parallel ILS approach
operations. Each runway is assigned a final monitor
controller during simultaneous parallel and simulta©\
neous close parallel ILS approaches. Final monitor
controllers shall utilize the Precision Runway
Monitor (PRM) system during simultaneous close
parallel ILS approaches.
FIR(See FLIGHT INFORMATION REGION.)
FIRST TIER CENTER- The ARTCC immediately
adjacent to the impacted center.
FIX- A geographical position determined by visual
reference to the surface, by reference to one or more
radio NAVAIDs, by celestial plotting, or by another
navigational device.
FIX BALANCING- A process whereby aircraft are
evenly distributed over several available arrival fixes
reducing delays and controller workload.
FLAG- A warning device incorporated in certain
airborne navigation and flight instruments indicating
that:
a. Instruments are inoperative or otherwise not
operating satisfactorily, or
b. Signal strength or quality of the received signal
falls below acceptable values.
FLAG ALARM(See FLAG.)
FLAMEOUT- An emergency condition caused by a
loss of engine power.
FLAMEOUT PATTERN- An approach normally
conducted by a single©\engine military aircraft
experiencing loss or anticipating loss of engine
Pilot/Controller Glossary 2/14/08
PCG F-3
power or control. The standard overhead approach
starts at a relatively high altitude over a runway
(¡°high key¡±) followed by a continuous 180 degree
turn to a high, wide position (¡°low key¡±) followed by
a continuous 180 degree turn final. The standard
straight©\in pattern starts at a point that results in a
straight©\in approach with a high rate of descent to the
runway. Flameout approaches terminate in the type
approach requested by the pilot (normally fullstop).
FLIGHT CHECK- A call©\sign prefix used by FAA
aircraft engaged in flight inspection/certification of
navigational aids and flight procedures. The word
¡°recorded¡± may be added as a suffix; e.g., ¡°Flight
Check 320 recorded¡± to indicate that an automated
flight inspection is in progress in terminal areas.
(See FLIGHT INSPECTION.)
(Refer to AIM.)
FLIGHT FOLLOWING(See TRAFFIC ADVISORIES.)
FLIGHT INFORMATION REGION- An airspace of
defined dimensions within which Flight Information
Service and Alerting Service are provided.
a. Flight Information Service. A service provided
for the purpose of giving advice and information
useful for the safe and efficient conduct of flights.
b. Alerting Service. A service provided to notify
appropriate organizations regarding aircraft in need
of search and rescue aid and to assist such
organizations as required.
FLIGHT INFORMATION SERVICE- A service
provided for the purpose of giving advice and
information useful for the safe and efficient conduct
of flights.
FLIGHT INSPECTION- Inflight investigation and
evaluation of a navigational aid to determine whether
it meets established tolerances.
(See FLIGHT CHECK.)
(See NAVIGATIONAL AID.)
FLIGHT LEVEL- A level of constant atmospheric
pressure related to a reference datum of 29.92 inches
of mercury. Each is stated in three digits that represent
hundreds of feet. For example, flight level (FL) 250
represents a barometric altimeter indication of
25,000 feet; FL 255, an indication of 25,500 feet.
(See ICAO term FLIGHT LEVEL.)
FLIGHT LEVEL [ICAO]- A surface of constant
atmospheric pressure which is related to a specific
pressure datum, 1013.2 hPa (1013.2 mb), and is
separated from other such surfaces by specific
pressure intervals.
Note 1:A pressure type altimeter calibrated in
accordance with the standard atmosphere:
a. When set to a QNH altimeter setting, will
indicate altitude;
b. When set to a QFE altimeter setting, will
indicate height above the QFE reference datum;
and
c. When set to a pressure of 1013.2 hPa
(1013.2 mb), may be used to indicate flight levels.
Note 2:The terms `height' and `altitude,' used in
Note 1 above, indicate altimetric rather than
geometric heights and altitudes.
FLIGHT LINE- A term used to describe the precise
movement of a civil photogrammetric aircraft along
a predetermined course(s) at a predetermined altitude
during the actual photographic run.
FLIGHT MANAGEMENT SYSTEMS- A comput©\
er system that uses a large data base to allow routes
to be preprogrammed and fed into the system by
means of a data loader. The system is constantly
updated with respect to position accuracy by
reference to conventional navigation aids. The
sophisticated program and its associated data base
insures that the most appropriate aids are automati©\
cally selected during the information update cycle.
FLIGHT MANAGEMENT SYSTEM PROCE©\
DURE- An arrival, departure, or approach procedure
developed for use by aircraft with a slant (/) E or slant
(/) F equipment suffix.
FLIGHT PATH- A line, course, or track along which
an aircraft is flying or intended to be flown.
(See COURSE.)
(See TRACK.)
FLIGHT PLAN- Specified information relating to
the intended flight of an aircraft that is filed orally or
in writing with an FSS or an ATC facility.
(See FAST FILE.)
(See FILED.)
(Refer to AIM.)
FLIGHT PLAN AREA- The geographical area
assigned by regional air traffic divisions to a flight
service station for the purpose of search and rescue
for VFR aircraft, issuance of NOTAMs, pilot
briefing, in©\flight services, broadcast, emergency
services, flight data processing, international opera©\
tions, and aviation weather services. Three letter
Pilot/Controller Glossary 2/14/08
PCG F-4
identifiers are assigned to every flight service station
and are annotated in AFDs and FAAO JO 7350.8,
LOCATION IDENTIFIERS, as tie©\in facilities.
(See FAST FILE.)
(See FILED.)
(Refer to AIM.)
FLIGHT RECORDER- A general term applied to
any instrument or device that records information
about the performance of an aircraft in flight or about
conditions encountered in flight. Flight recorders
may make records of airspeed, outside air
temperature, vertical acceleration, engine RPM,
manifold pressure, and other pertinent variables for a
given flight.
(See ICAO term FLIGHT RECORDER.)
FLIGHT RECORDER [ICAO]- Any type of
recorder installed in the aircraft for the purpose of
complementing accident/incident investigation.
Note:See Annex 6 Part I, for specifications relating
to flight recorders.
FLIGHT SERVICE STATION- Air traffic facilities
which provide pilot briefing, en route communica©\
tions and VFR search and rescue services, assist lost
aircraft and aircraft in emergency situations, relay
ATC clearances, originate Notices to Airmen,
broadcast aviation weather and NAS information,
and receive and process IFR flight plans. In addition,
at selected locations, FSSs provide En Route Flight
Advisory Service (Flight Watch), issue airport
advisories, and advise Customs and Immigration of
transborder flights. Selected Flight Service Stations
in Alaska also provide TWEB recordings and take
weather observations.
(Refer to AIM.)
FLIGHT STANDARDS DISTRICT OFFICE- An
FAA field office serving an assigned geographical
area and staffed with Flight Standards personnel who
serve the aviation industry and the general public on
matters relating to the certification and operation of
air carrier and general aviation aircraft. Activities
include general surveillance of operational safety,
certification of airmen and aircraft, accident
prevention, investigation, enforcement, etc.
FLIGHT TEST- A flight for the purpose of:
a. Investigating the operation/flight characteris©\
tics of an aircraft or aircraft component.
b. Evaluating an applicant for a pilot certificate or
rating.
FLIGHT VISIBILITY(See VISIBILITY.)
FLIGHT WATCH- A shortened term for use in
air©\ground contacts to identify the flight service
station providing En Route Flight Advisory Service;
e.g., ¡°Oakland Flight Watch.¡±
(See EN ROUTE FLIGHT ADVISORY
SERVICE.)
FLIP(See DOD FLIP.)
FLY HEADING (DEGREES)- Informs the pilot of
the heading he/she should fly. The pilot may have to
turn to, or continue on, a specific compass direction
in order to comply with the instructions. The pilot is
expected to turn in the shorter direction to the heading
unless otherwise instructed by ATC.
FLY©\BY WAYPOINT- A fly©\by waypoint requires
the use of turn anticipation to avoid overshoot of the
next flight segment.
FLY©\OVER WAYPOINT- A fly©\over waypoint
precludes any turn until the waypoint is overflown
and is followed by an intercept maneuver of the next
flight segment.
FMA(See FINAL MONITOR AID.)
FMS(See FLIGHT MANAGEMENT SYSTEM.)
FMSP(See FLIGHT MANAGEMENT SYSTEM
PROCEDURE.)
FORMATION FLIGHT- More than one aircraft
which, by prior arrangement between the pilots,
operate as a single aircraft with regard to navigation
and position reporting. Separation between aircraft
within the formation is the responsibility of the flight
leader and the pilots of the other aircraft in the flight.
This includes transition periods when aircraft within
the formation are maneuvering to attain separation
from each other to effect individual control and
during join©\up and breakaway.
a. A standard form ation is one in which a
proximity of no more than 1 mile laterally or
longitudinally and within 100 feet vertically from the
flight leader is maintained by each wingman.
b. Nonstandard formations are those operating
under any of the following conditions:
Pilot/Controller Glossary 2/14/08
PCG F-5
1. When the flight leader has requested and ATC
has approved other than standard form ation
dimensions.
2. When operating within an authorized altitude
reservation (ALTRV) or under the provisions of a
letter of agreement.
3. When the operations are conducted in
airspace specifically designed for a special activity.
(See ALTITUDE RESERVATION.)
(Refer to 14 CFR Part 91.)
FRC(See REQUEST FULL ROUTE CLEARANCE.)
FREEZE/FROZEN- Terms used in referring to
arrivals which have been assigned ACLTs and to the
lists in which they are displayed.
FREEZE CALCULATED LANDING TIME- A
dynamic parameter number of minutes prior to the
meter fix calculated time of arrival for each aircraft
when the TCLT is frozen and becomes an ACLT (i.e.,
the VTA is updated and consequently the TCLT is
modified as appropriate until FCLT minutes prior to
meter fix calculated time of arrival, at which time
updating is suspended and an ACLT and a frozen
meter fix crossing time (MFT) is assigned).
FREEZE HORIZON- The time or point at which an
aircraft's STA becomes fixed and no longer fluctuates
with each radar update. This setting insures a constant
time for each aircraft, necessary for the metering
controller to plan his/her delay technique. This
setting can be either in distance from the meter fix or
a prescribed flying time to the meter fix.
FREEZE SPEED PARAMETER- A speed adapted
for each aircraft to determine fast and slow aircraft.
Fast aircraft freeze on parameter FCLT and slow
aircraft freeze on parameter MLDI.
FRICTION MEASUREMENT- A measurement of
the friction characteristics of the runway pavement
surface using continuous self©\watering friction
measurement equipment in accordance with the
specifications, procedures and schedules contained
in AC 150/5320-12, Measurement, Construction,
and Maintenance of Skid Resistant Airport Pavement
Surfaces.
FSDO(See FLIGHT STANDARDS DISTRICT OFFICE.)
FSPD(See FREEZE SPEED PARAMETER.)
FSS(See FLIGHT SERVICE STATION.)
FUEL DUMPING- Airborne release of usable fuel.
This does not include the dropping of fuel tanks.
(See JETTISONING OF EXTERNAL STORES.)
FUEL REMAINING- A phrase used by either pilots
or controllers when relating to the fuel remaining on
board until actual fuel exhaustion. When transmitting
such information in response to either a controller
question or pilot initiated cautionary advisory to air
traffic control, pilots will state the APPROXIMATE
NUMBER OF MINUTES the flight can continue
with the fuel remaining. All reserve fuel SHOULD
BE INCLUDED in the time stated, as should an
allowance for established fuel gauge system error.
FUEL SIPHONING- Unintentional release of fuel
caused by overflow, puncture, loose cap, etc.
FUEL VENTING(See FUEL SIPHONING.)
Pilot/Controller Glossary 2/14/08
PCG G-1
G
GATE HOLD PROCEDURES- Procedures at
selected airports to hold aircraft at the gate or other
ground location whenever departure delays exceed or
are anticipated to exceed 15 minutes. The sequence
for departure will be maintained in accordance with
initial call©\up unless modified by flow control
restrictions. Pilots should monitor the ground
control/clearance delivery frequency for engine
start/taxi advisories or new proposed start/taxi time
if the delay changes.
GBT(See GROUND-BASED TRANSCEIVER.)
GCA(See GROUND CONTROLLED APPROACH.)
GDP(See GROUND DELAY PROGRAM.)
GENERAL AVIATION- That portion of civil
aviation which encompasses all facets of aviation
except air carriers holding a certificate of public
convenience and necessity from the Civil Aeronau©\
tics Board and large aircraft commercial operators.
(See ICAO term GENERAL AVIATION.)
GENERAL AVIATION [ICAO]- All civil aviation
operations other than scheduled air services and
nonscheduled air transport operations for remunera©\
tion or hire.
GEO MAP- The digitized map markings associated
with the ASR©\9 Radar System.
GLIDEPATH(See GLIDESLOPE.)
GLIDEPATH [ICAO]- A descent profile determined
for vertical guidance during a final approach.
GLIDEPATH INTERCEPT ALTITUDE(See GLIDESLOPE INTERCEPT ALTITUDE.)
GLIDESLOPE- Provides vertical guidance for
aircraft during approach and landing. The glideslope/
glidepath is based on the following:
a. Electronic components emitting signals which
provide vertical guidance by reference to airborne
instruments during instrument approaches such as
ILS/MLS, or
b. Visual ground aids, such as VASI, which
provide vertical guidance for a VFR approach or for
the visual portion of an instrument approach and
landing.
c. AR. Used by ATC to inform an aircraft making
a PAR approach of its vertical position (elevation)
relative to the descent profile.
(See ICAO term GLIDEPATH.)
GLIDESLOPE INTERCEPT ALTITUDE- The
minimum altitude to intercept the glideslope/path on
a precision approach. The intersection of the
published intercept altitude with the glideslope/path,
designated on Government charts by the lightning
bolt symbol, is the precision FAF; however, when the
approach chart shows an alternative lower glideslope
intercept altitude, and ATC directs a lower altitude,
the resultant lower intercept position is then the FAF.
(See FINAL APPROACH FIX.)
(See SEGMENTS OF AN INSTRUMENT
APPROACH PROCEDURE.)
GLOBAL POSITIONING SYSTEM (GPS)- A
space©\base radio positioning, navigation, and
time©\transfer system. The system provides highly
accurate position and velocity information, and
precise time, on a continuous global basis, to an
unlimited number of properly equipped users. The
system is unaffected by weather, and provides a
worldwide common grid reference system. The GPS
concept is predicated upon accurate and continuous
knowledge of the spatial position of each satellite in
the system with respect to time and distance from a
transmitting satellite to the user. The GPS receiver
automatically selects appropriate signals from the
satellites in view and translates these into three©\
dimensional position, velocity, and time. System
accuracy for civil users is normally 100 meters
horizontally.
GO AHEAD- Proceed with your message. Not to be
used for any other purpose.
GO AROUND- Instructions for a pilot to abandon
his/her approach to landing. Additional instructions
may follow. Unless otherwise advised by ATC, a
VFR aircraft or an aircraft conducting visual
approach should overfly the runway while climbing
to traffic pattern altitude and enter the traffic pattern
via the crosswind leg. A pilot on an IFR flight plan
Pilot/Controller Glossary 2/14/08
PCG G-2
making an instrument approach should execute the
published missed approach procedure or proceed as
instructed by ATC; e.g., ¡°Go around¡± (additional
instructions if required).
(See LOW APPROACH.)
(See MISSED APPROACH.)
GPD(See GRAPHIC PLAN DISPLAY.)
GPS(See GLOBAL POSITIONING SYSTEM.)
GRAPHIC PLAN DIS PLAY (GPD)- A view
available with URET that provides a graphic display
of aircraft, traffic, and notification of predicted
conflicts. Graphic routes for Current Plans and Trial
Plans are displayed upon controller request.
(See USER REQUEST EVALUATION TOOL.)
GROUND-BASED TRANSCEIVER (GBT)- The
ground-based transmitter/receiver (transceiver) re©\
ceives automatic dependent surveillance-broadcast
messages, which are forwarded to an air traffic
control facility for processing and display with other
radar targets on the plan position indicator (radar
display).
(See AUTOMATIC DEPENDENT
SURVEILLANCE©\BROADCAST.)
GROUND CLUTTER- A pattern produced on the
radar scope by ground returns which may degrade
other radar returns in the affected area. The effect of
ground clutter is minimized by the use of moving
target indicator (MTI) circuits in the radar equipment
resulting in a radar presentation which displays only
targets which are in motion.
(See CLUTTER.)
GROUND COMMUNICATION OUTLET (GCO)-
An unstaffed, remotely controlled, ground/ground
communications facility. Pilots at uncontrolled
airports may contact ATC and FSS via VHF to a
telephone connection to obtain an instrument
clearance or close a VFR or IFR flight plan. They may
also get an updated weather briefing prior to takeoff.
Pilots will use four ¡°key clicks¡± on the VHF radio to
contact the appropriate ATC facility or six ¡°key
clicks¡± to contact the FSS. The GCO system is
intended to be used only on the ground.
GROUND CONTROLLED APPROACH- A radar
approach system operated from the ground by air
traffic control personnel transmitting instructions to
the pilot by radio. The approach may be conducted
with surveillance radar (ASR) only or with both
surveillance and precision approach radar (PAR).
Usage of the term ¡°GCA¡± by pilots is discouraged
except when referring to a GCA facility. Pilots should
specifically request a ¡°PAR¡± approach when a
precision radar approach is desired or request an
¡°ASR¡± or ¡°surveillance¡± approach when a nonpreci©\
sion radar approach is desired.
(See RADAR APPROACH.)
GROUND DELAY PROGRAM (GDP)- A traffic
management process administered by the ATCSCC;
when aircraft are held on the ground. The purpose of
the program is to support the TM mission and limit
airborne holding. It is a flexible program and may be
implemented in various forms depending upon the
needs of the AT system. Ground delay programs
provide for equitable assignment of delays to all
system users.
GROUND SPEED- The speed of an aircraft relative
to the surface of the earth.
GROUND STOP (GS)- The GS is a process that
requires aircraft that meet a specific criteria to remain
on the ground. The criteria may be airport specific,
airspace specific, or equipment specific; for example,
all departures to San Francisco, or all departures
entering Yorktown sector, or all Category I and II
aircraft going to Charlotte. GSs normally occur with
little or no warning.
GROUND VISIBILITY(See VISIBILITY.)
GS(See GROUND STOP.)
Pilot/Controller Glossary 2/14/08
PCG H-1
H
HAA(See HEIGHT ABOVE AIRPORT.)
HAL(See HEIGHT ABOVE LANDING.)
HANDOFF- An action taken to transfer the radar
identification of an aircraft from one controller to
another if the aircraft will enter the receiving
controller's airspace and radio communications with
the aircraft will be transferred.
HAR(See HIGH ALTITUDE REDESIGN.)
HAT(See HEIGHT ABOVE TOUCHDOWN.)
HAVE NUMBERS- Used by pilots to inform ATC
that they have received runway, wind, and altimeter
information only.
HAZARDOUS INFLIGHT WEATHER ADVISO©\
RY SERVICE- Continuous recorded hazardous
inflight weather forecasts broadcasted to airborne
pilots over selected VOR outlets defined as an
HIWAS BROADCAST AREA.
HAZARDOUS WEATHER INFORMATION-
Summary of significant meteorological information
(SIGMET/WS), convective significant meteorologi©\
cal information (convective SIGMET/WST), urgent
pilot weather reports (urgent PIREP/UUA), center
weather advisories (CWA), airmen's meteorological
information (AIRMET/WA) and any other weather
such as isolated thunderstorms that are rapidly
developing and increasing in intensity, or low
ceilings and visibilities that are becoming wide©\
spread which is considered significant and are not
included in a current hazardous weather advisory.
HEAVY (AIRCRAFT)-
(See AIRCRAFT CLASSES.)
HEIGHT ABOVE AIRPORT- The height of the
Minimum Descent Altitude above the published
airport elevation. This is published in conjunction
with circling minimums.
(See MINIMUM DESCENT ALTITUDE.)
HEIGHT ABOVE LANDING- The height above a
designated helicopter landing area used for helicopter
instrument approach procedures.
(Refer to 14 CFR Part 97.)
HEIGHT ABOVE TOUCHDOWN- The height of
the Decision Height or Minimum Descent Altitude
above the highest runway elevation in the touchdown
zone (first 3,000 feet of the runway). HAT is
published on instrument approach charts in conjunc©\
tion with all straight©\in minimums.
(See DECISION HEIGHT.)
(See MINIMUM DESCENT ALTITUDE.)
HELICOPTER- Rotorcraft that, for its horizontal
motion, depends principally on its engine©\driven
rotors.
(See ICAO term HELICOPTER.)
HELICOPTER [ICAO]- A heavier©\than©\air aircraft
supported in flight chiefly by the reactions of the air
on one or more power©\driven rotors on substantially
vertical axes.
HELIPAD- A small, designated area, usually with a
prepared surface, on a heliport, airport, landing/take©\
off area, apron/ramp, or movement area used for
takeoff, landing, or parking of helicopters.
HELIPORT- An area of land, water, or structure used
or intended to be used for the landing and takeoff of
helicopters and includes its buildings and facilities if
any.
HELIPORT REFERENCE POINT (HRP)- The
geographic center of a heliport.
HERTZ- The standard radio equivalent of frequency
in cycles per second of an electromagnetic wave.
Kilohertz (kHz) is a frequency of one thousand cycles
per second. Megahertz (MHz) is a frequency of one
million cycles per second.
HF(See HIGH FREQUENCY.)
HF COMMUNICATIONS(See HIGH FREQUENCY COMMUNICATIONS.)
HIGH ALTITUDE REDESIGN (HAR)- A level of
non-restrictive routing (NRR) service for aircraft
that have all waypoints associated with the HAR
program in their flight management systems or
RNAV equipage.
Pilot/Controller Glossary 2/14/08
PCG H-2
HIGH FREQUENCY- The frequency band between
3 and 30 MHz.
(See HIGH FREQUENCY COMMUNICATIONS.)
HIGH FREQUENCY COMMUNICATIONS- High
radio frequencies (HF) between 3 and 30 MHz used
for air©\to©\ground voice communication in overseas
operations.
HIGH SPEED EXIT(See HIGH SPEED TAXIWAY.)
HIGH SPEED TAXIWAY- A long radius taxiway
designed and provided with lighting or marking to
define the path of aircraft, traveling at high speed (up
to 60 knots), from the runway center to a point on the
center of a taxiway. Also referred to as long radius
exit or turn©\off taxiway. The high speed taxiway is
designed to expedite aircraft turning off the runway
after landing, thus reducing runway occupancy time.
HIGH SPEED TURNOFF(See HIGH SPEED TAXIWAY.)
HIWAS(See HAZARDOUS INFLIGHT WEATHER
ADVISORY SERVICE.)
HIWAS AREA(See HAZARDOUS INFLIGHT WEATHER
ADVISORY SERVICE.)
HIWAS BROADCAST AREA- A geographical area
of responsibility including one or more HIWAS
outlet areas assigned to an AFSS/FSS for hazardous
weather advisory broadcasting.
HIWAS OUTLET AREA- An area defined as a 150
NM radius of a HIWAS outlet, expanded as necessary
to provide coverage.
HOLD FOR RELEASE- Used by ATC to delay an
aircraft for traffic management reasons; i.e., weather,
traffic volume, etc. Hold for release instructions
(including departure delay information) are used to
inform a pilot or a controller (either directly or
through an authorized relay) that an IFR departure
clearance is not valid until a release time or additional
instructions have been received.
(See ICAO term HOLDING POINT.)
HOLD IN LIEU OF PROCEDURE TURN- A hold
in lieu of procedure turn shall be established over a
final or intermediate fix when an approach can be
made from a properly aligned holding pattern. The
hold in lieu of procedure turn permits the pilot to
align with the final or intermediate segment of the
approach and/or descend in the holding pattern to an
altitude that will permit a normal descent to the final
approach fix altitude. The hold in lieu of procedure
turn is a required maneuver (the same as a procedure
turn) unless the aircraft is being radar vectored to the
final approach course, when ¡°NoPT¡± is shown on the
approach chart, or when the pilot requests or the
controller advises the pilot to make a ¡°straight-in¡±
approach.
HOLD PROCEDURE- A predetermined maneuver
which keeps aircraft within a specified airspace while
awaiting further clearance from air traffic control.
Also used during ground operations to keep aircraft
within a specified area or at a specified point while
awaiting further clearance from air traffic control.
(See HOLDING FIX.)
(Refer to AIM.)
HOLDING FIX- A specified fix identifiable to a
pilot by NAVAIDs or visual reference to the ground
used as a reference point in establishing and
maintaining the position of an aircraft while holding.
(See FIX.)
(See VISUAL HOLDING.)
(Refer to AIM.)
HOLDING POINT [ICAO]- A specified location,
identified by visual or other means, in the vicinity of
which the position of an aircraft in flight is
maintained in accordance with air traffic control
clearances.
HOLDING PROCEDURE(See HOLD PROCEDURE.)
HOLD©\SHORT POINT- A point on the runway
beyond which a landing aircraft with a LAHSO
clearance is not authorized to proceed. This point
may be located prior to an intersecting runway,
taxiway, predetermined point, or approach/departure
flight path.
HOLD©\SHORT POSITION LIGHTS- Flashing
in©\pavement white lights located at specified
hold©\short points.
HOLD©\SHORT POSITION MARKING- The
painted runway marking located at the hold©\short
point on all LAHSO runways.
HOLD©\SHORT POSITION SIGNS- Red and white
holding position signs located alongside the
hold©\short point.
Pilot/Controller Glossary 2/14/08
PCG H-3
HOMING- Flight toward a NAVAID, without
correcting for wind, by adjusting the aircraft heading
to maintain a relative bearing of zero degrees.
(See BEARING.)
(See ICAO term HOMING.)
HOMING [ICAO]- The procedure of using the
direction©\finding equipment of one radio station with
the emission of another radio station, where at least
one of the stations is mobile, and whereby the mobile
station proceeds continuously towards the other
station.
HOVER CHECK- Used to describe when a
helicopter/VTOL aircraft requires a stabilized hover
to conduct a performance/power check prior to hover
taxi, air taxi, or takeoff. Altitude of the hover will
vary based on the purpose of the check.
HOVER TAXI- Used to describe a helicopter/VTOL
aircraft movement conducted above the surface and
in ground effect at airspeeds less than approximately
20 knots. The actual height may vary, and some
helicopters may require hover taxi above 25 feet AGL
to reduce ground effect turbulence or provide
clearance for cargo slingloads.
(See AIR TAXI.)
(See HOVER CHECK.)
(Refer to AIM.)
HOW DO YOU HEAR ME?- A question relating to
the quality of the transmission or to determine how
well the transmission is being received.
HZ(See HERTZ.)
Pilot/Controller Glossary 2/14/08
PCG I-1
I
I SAY AGAIN- The message will be repeated.
IAF(See INITIAL APPROACH FIX.)
IAP(See INSTRUMENT APPROACH
PROCEDURE.)
IAWP- Initial Approach Waypoint
ICAO(See ICAO Term INTERNATIONAL CIVIL
AVIATION ORGANIZATION.)
ICING- The accumulation of airframe ice.
Types of icing are:
a. Rime Ice- Rough, milky, opaque ice formed by
the instantaneous freezing of small supercooled
water droplets.
b. Clear Ice- A glossy, clear, or translucent ice
formed by the relatively slow freezing or large
supercooled water droplets.
c. Mixed- A mixture of clear ice and rime ice.
Intensity of icing:
a. Trace- Ice becomes perceptible. Rate of
accumulation is slightly greater than the rate of
sublimation. Deicing/anti©\icing equipment is not
utilized unless encountered for an extended period of
time (over 1 hour).
b. Light- The rate of accumulation may create a
problem if flight is prolonged in this environment
(over 1 hour). Occasional use of deicing/anti©\icing
equipment removes/prevents accumulation. It does
not present a problem if the deicing/anti©\icing
equipment is used.
c. Moderate- The rate of accumulation is such that
even short encounters become potentially hazardous
and use of deicing/anti©\icing equipment or flight
diversion is necessary.
d. Severe- The rate of accumulation is such that
deicing/anti©\icing equipment fails to reduce or
control the hazard. Immediate flight diversion is
necessary.
IDENT- A request for a pilot to activate the aircraft
transponder identification feature. This will help the
controller to confirm an aircraft identity or to identify
an aircraft.
(Refer to AIM.)
IDENT FEATURE- The special feature in the Air
Traffic Control Radar Beacon System (ATCRBS)
equipment. It is used to immediately distinguish one
displayed beacon target from other beacon targets.
(See IDENT.)
IF(See INTERMEDIATE FIX.)
IFIM(See INTERNATIONAL FLIGHT INFORMATION
MANUAL.)
IF NO TRANSMISSION RECEIVED FOR
(TIME)- Used by ATC in radar approaches to prefix
procedures which should be followed by the pilot in
event of lost communications.
(See LOST COMMUNICATIONS.)
IFR(See INSTRUMENT FLIGHT RULES.)
IFR AIRCRAFT- An aircraft conducting flight in
accordance with instrument flight rules.
IFR CONDITIONS- Weather conditions below the
minimum for flight under visual flight rules.
(See INSTRUMENT METEOROLOGICAL
CONDITIONS.)
IFR DEPARTURE PROCEDURE(See IFR TAKEOFF MINIMUMS AND
DEPARTURE PROCEDURES.)
(Refer to AIM.)
IFR FLIGHT(See IFR AIRCRAFT.)
IFR LANDING MINIMUMS(See LANDING MINIMUMS.)
IFR MILITARY TRAINING ROUTES (IR)- Routes
used by the Department of Defense and associated
Reserve and Air Guard units for the purpose of
conducting low©\altitude navigation and tactical
training in both IFR and VFR weather conditions
below 10,000 feet MSL at airspeeds in excess of 250
knots IAS.
IFR TAKEOFF MINIMUMS AND DEPARTURE
PROCEDURES- Title 14 Code of Federal
Pilot/Controller Glossary 2/14/08
PCG I-2
Regulations Part 91, prescribes standard takeoff rules
for certain civil users. At some airports, obstructions
or other factors require the establishm ent of
nonstandard takeoff minimums, departure proce©\
dures, or both to assist pilots in avoiding obstacles
during climb to the minimum en route altitude. Those
airports are listed in FAA/DOD Instrument Approach
Procedures (IAPs) Charts under a section entitled
¡°IFR Takeoff Minimums and Departure Procedures.¡±
The FAA/DOD IAP chart legend illustrates the
symbol used to alert the pilot to nonstandard takeoff
minimums and departure procedures. When depart©\
ing IFR from such airports or from any airports where
there are no departure procedures, DPs, or ATC
facilities available, pilots should advise ATC of any
departure limitations. Controllers may query a pilot
to determine acceptable departure directions, turns,
or headings after takeoff. Pilots should be familiar
with the departure procedures and must assure that
their aircraft can meet or exceed any specified climb
gradients.
IF/IAWP- Intermediate Fix/Initial Approach Way©\
point. The waypoint where the final approach course
of a T approach meets the crossbar of the T. When
designated (in conjunction with a TAA) this
waypoint will be used as an IAWP when approaching
the airport from certain directions, and as an IFWP
when beginning the approach from another IAWP.
IFWP- Intermediate Fix Waypoint
ILS(See INSTRUMENT LANDING SYSTEM.)
ILS CATEGORIES- 1. ILS Category I. An ILS
approach procedure which provides for approach to
a height above touchdown of not less than 200 feet
and with runway visual range of not less than 1,800
feet.- 2. ILS Category II. An ILS approach procedure
which provides for approach to a height above
touchdown of not less than 100 feet and with runway
visual range of not less than 1,200 feet.- 3. ILS
Category III:
a. IIIA.-An ILS approach procedure which
provides for approach without a decision height
minimum and with runway visual range of not less
than 700 feet.
b. IIIB.-An ILS approach procedure which
provides for approach without a decision height
minimum and with runway visual range of not less
than 150 feet.
c. IIIC.-An ILS approach procedure which
provides for approach without a decision height
minimum and without runway visual range
minimum.
ILS PRM APPROACH- An instrument landing
system (ILS) approach conducted to parallel runways
whose extended centerlines are separated by less than
4,300 feet and the parallel runways have a Precision
Runway Monitoring (PRM) system that permits
simultaneous independent ILS approaches.
IM(See INNER MARKER.)
IMC(See INSTRUMENT METEOROLOGICAL
CONDITIONS.)
IMMEDIATELY- Used by ATC or pilots when such
action compliance is required to avoid an imminent
situation.
INCERFA (Uncertainty Phase) [ICAO]- A situation
wherein uncertainty exists as to the safety of an
aircraft and its occupants.
INCREASE SPEED TO (SPEED)-
(See SPEED ADJUSTMENT.)
INERTIAL NAVIGATION SYSTEM- An RNAV
system which is a form of self©\contained navigation.
(See Area Navigation/RNAV.)
INFLIGHT REFUELING(See AERIAL REFUELING.)
INFLIGHT WEATHER ADVISORY(See WEATHER ADVISORY.)
INFORMATION REQUEST- A request originated
by an FSS for information concerning an overdue
VFR aircraft.
INITIAL APPROACH FIX- The fixes depicted on
instrument approach procedure charts that identify
the beginning of the initial approach segment(s).
(See FIX.)
(See SEGMENTS OF AN INSTRUMENT
APPROACH PROCEDURE.)
INITIAL APPROACH SEGMENT(See SEGMENTS OF AN INSTRUMENT
APPROACH PROCEDURE.)
INITIAL APPROACH SEGMENT [ICAO]- That
segment of an instrument approach procedure
between the initial approach fix and the intermediate
approach fix or, where applicable, the final approach
fix or point.
Pilot/Controller Glossary 2/14/08
PCG I-3
INLAND NAVIGATION FACILITY- A navigation
aid on a North American Route at which the common
route and/or the noncommon route begins or ends.
INNER MARKER- A marker beacon used with an
ILS (CAT II) precision approach located between the
middle marker and the end of the ILS runway,
transmitting a radiation pattern keyed at six dots per
second and indicating to the pilot, both aurally and
visually, that he/she is at the designated decision
height (DH), normally 100 feet above the touchdown
zone elevation, on the ILS CAT II approach. It also
marks progress during a CAT III approach.
(See INSTRUMENT LANDING SYSTEM.)
(Refer to AIM.)
INNER MARKER BEACON(See INNER MARKER.)
INREQ(See INFORMATION REQUEST.)
INS(See INERTIAL NAVIGATION SYSTEM.)
INSTRUMENT APPROACH(See INSTRUMENT APPROACH
PROCEDURE.)
INSTRUMENT APPROACH PROCEDURE- A
series of predetermined maneuvers for the orderly
transfer of an aircraft under instrument flight
conditions from the beginning of the initial approach
to a landing or to a point from which a landing may
be made visually. It is prescribed and approved for a
specific airport by competent authority.
(See SEGMENTS OF AN INSTRUMENT
APPROACH PROCEDURE.)
(Refer to 14 CFR Part 91.)
(Refer to AIM.)
a. U.S. civil standard instrument approach
procedures are approved by the FAA as prescribed
under 14 CFR Part 97 and are available for public
use.
b. U.S. military standard instrument approach
procedures are approved and published by the
Department of Defense.
c. Special instrument approach procedures are
approved by the FAA for individual operators but are
not published in 14 CFR Part 97 for public use.
(See ICAO term INSTRUMENT APPROACH
PROCEDURE.)
INSTRUMENT APPROACH PROCEDURE
[ICAO]- A series of predetermined maneuvers by
reference to flight instruments with specified
protection from obstacles from the initial approach
fix, or where applicable, from the beginning of a
defined arrival route to a point from which a landing
can be completed and thereafter, if a landing is not
completed, to a position at which holding or en route
obstacle clearance criteria apply.
INSTRUMENT APPROACH PROCEDURES
CHARTS(See AERONAUTICAL CHART.)
INSTRUMENT DEPARTURE PROCEDURE
(DP)- A preplanned instrument flight rule (IFR)
departure procedure published for pilot use, in
graphic or textual format, that provides obstruction
clearance from the terminal area to the appropriate en
route structure. There are two types of DP, Obstacle
Departure Procedure (ODP), printed either textually
or graphically, and, Standard Instrument Departure
(SID), which is always printed graphically.
(See IFR TAKEOFF MINIMUMS AND
DEPARTURE PROCEDURES.)
(See OBSTACLE DEPARTURE PROCEDURES.)
(See STANDARD INSTRUMENT DEPARTURES.)
(Refer to AIM.)
INSTRUMENT DEPARTURE PROCEDURE (DP)
CHARTS(See AERONAUTICAL CHART.)
INSTRUMENT FLIGHT RULES- Rules governing
the procedures for conducting instrument flight. Also
a term used by pilots and controllers to indicate type
of flight plan.
(See INSTRUMENT METEOROLOGICAL
CONDITIONS.)
(See VISUAL FLIGHT RULES.)
(See VISUAL METEOROLOGICAL
CONDITIONS.)
(See ICAO term INSTRUMENT FLIGHT
RULES.)
(Refer to AIM.)
INSTRUMENT FLIGHT RULES [ICAO]- A set of
rules governing the conduct of flight under
instrument meteorological conditions.
INSTRUMENT LANDING SYSTEM- A precision
instrument approach system which normally consists
of the following electronic components and visual
aids:
Pilot/Controller Glossary 2/14/08
PCG I-4
a. Localizer.
(See LOCALIZER.)
b. Glideslope.
(See GLIDESLOPE.)
c. Outer Marker.
(See OUTER MARKER.)
d. Middle Marker.
(See MIDDLE MARKER.)
e. Approach Lights.
(See AIRPORT LIGHTING.)
(Refer to 14 CFR Part 91.)
(Refer to AIM.)
INSTRUMENT METEOROLOGICAL CONDI©\
TIONS- Meteorological conditions expressed in
terms of visibility, distance from cloud, and ceiling
less than the minima specified for visual meteorolog©\
ical conditions.
(See INSTRUMENT FLIGHT RULES.)
(See VISUAL FLIGHT RULES.)
(See VISUAL METEOROLOGICAL
CONDITIONS.)
INSTRUMENT RUNWAY- A runway equipped
with electronic and visual navigation aids for which
a precision or nonprecision approach procedure
having straight©\in landing minimums has been
approved.
(See ICAO term INSTRUMENT RUNWAY.)
INSTRUMENT RUNWAY [ICAO]- One of the
following types of runways intended for the
operation of aircraft using instrument approach
procedures:
a. Nonprecision Approach Runway-An instru©\
ment runway served by visual aids and a nonvisual
aid providing at least directional guidance adequate
for a straight©\in approach.
b. recision Approach Runway, Category I-An
instrument runway served by ILS and visual aids
intended for operations down to 60 m (200 feet)
decision height and down to an RVR of the order of
800 m.
c. recision Approach Runway, Category II-An
instrument runway served by ILS and visual aids
intended for operations down to 30 m (100 feet)
decision height and down to an RVR of the order of
400 m.
d. recision Approach Runway, Category III-An
instrument runway served by ILS to and along the
surface of the runway and:
1. Intended for operations down to an RVR of
the order of 200 m (no decision height being
applicable) using visual aids during the final phase of
landing;
2. Intended for operations down to an RVR of
the order of 50 m (no decision height being
applicable) using visual aids for taxiing;
3. Intended for operations without reliance on
visual reference for landing or taxiing.
Note 1:See Annex 10 Volume I, Part I, Chapter 3,
for related ILS specifications.
Note 2:Visual aids need not necessarily be
matched to the scale of nonvisual aids provided.
The criterion for the selection of visual aids is the
conditions in which operations are intended to be
conducted.
INTEGRITY- The ability of a system to provide
timely warnings to users when the system should not
be used for navigation.
INTERMEDIATE APPROACH SEGMENT(See SEGMENTS OF AN INSTRUMENT
APPROACH PROCEDURE.)
INTERMEDIATE APPROACH SEGMENT
[ICAO]- That segment of an instrument approach
procedure between either the intermediate approach
fix and the final approach fix or point, or between the
end of a reversal, race track or dead reckoning track
procedure and the final approach fix or point, as
appropriate.
INTERMEDIATE FIX- The fix that identifies the
beginning of the intermediate approach segment of an
instrument approach procedure. The fix is not
normally identified on the instrument approach chart
as an intermediate fix (IF).
(See SEGMENTS OF AN INSTRUMENT
APPROACH PROCEDURE.)
INTERMEDIATE LANDING- On the rare occasion
that this option is requested, it should be approved.
The departure center, however, must advise the
ATCSCC so that the appropriate delay is carried over
and assigned at the interm ediate airport. An
intermediate landing airport within the arrival center
will not be accepted without coordination with and
the approval of the ATCSCC.
INTERNATIONAL AIRPORT- Relating to interna©\
tional flight, it means:
Pilot/Controller Glossary 2/14/08
PCG I-5
a. An airport of entry which has been designated
by the Secretary of Treasury or Commissioner of
Customs as an international airport for customs
service.
b. A landing rights airport at which specific
permission to land must be obtained from customs
authorities in advance of contemplated use.
c. Airports designated under the Convention on
International Civil Aviation as an airport for use by
international commercial air transport and/or interna©\
tional general aviation.
(See ICAO term INTERNATIONAL AIRPORT.)
(Refer to AIRPORT/FACILITY DIRECTORY.)
(Refer to IFIM.)
INTERNATIONAL AIRPORT [ICAO]- Any airport
designated by the Contracting State in whose
territory it is situated as an airport of entry and
departure for international air traffic, where the
formalities incident to customs, immigration, public
health, animal and plant quarantine and similar
procedures are carried out.
INTERNATIONAL CIVIL AVIATION ORGA©\
NIZATION [ICAO]- A specialized agency of the
United Nations whose objective is to develop the
principles and techniques of international air
navigation and to foster planning and development of
international civil air transport.
a. Regions include:
1. African©\Indian Ocean Region
2. Caribbean Region
3. European Region
4. Middle East/Asia Region
5. North American Region
6. North Atlantic Region
7. acific Region
8. South American Region
INTERNATIONAL FLIGHT INFORMATION
MANUAL- A publication designed primarily as a
pilot's preflight planning guide for flights into
foreign airspace and for flights returning to the U.S.
from foreign locations.
INTERROGATOR- The ground©\based surveillance
radar beacon transmitter©\receiver, which normally
scans in synchronism with a prim ary radar,
transmitting discrete radio signals which repetitious©\
ly request all transponders on the mode being used to
reply. The replies received are mixed with the
primary radar returns and displayed on the same plan
position indicator (radar scope). Also, applied to the
airborne element of the TACAN/DME system.
(See TRANSPONDER.)
(Refer to AIM.)
INTERSECTING RUNWAYS- Two or more
runways which cross or meet within their lengths.
(See INTERSECTION.)
INTERSECTIONa. A point defined by any combination of courses,
radials, or bearings of two or more navigational aids.
b. Used to describe the point where two runways,
a runway and a taxiway, or two taxiways cross or
meet.
INTERSECTION DEPARTURE- A departure from
any runway intersection except the end of the runway.
(See INTERSECTION.)
INTERSECTION TAKEOFF(See INTERSECTION DEPARTURE.)
IR(See IFR MILITARY TRAINING ROUTES.)
Pilot/Controller Glossary 2/14/08
PCG J-1
J
JAMMING- Electronic or mechanical interference
which may disrupt the display of aircraft on radar or
the transmission/reception of radio communications/
navigation.
JET BLAST- Jet engine exhaust (thrust stream
turbulence).
(See WAKE TURBULENCE.)
JET ROUTE- A route designed to serve aircraft
operations from 18,000 feet MSL up to and including
flight level 450. The routes are referred to as ¡°J¡±
routes with numbering to identify the designated
route; e.g., J105.
(See Class A AIRSPACE.)
(Refer to 14 CFR Part 71.)
JET STREAM- A migrating stream of high©\speed
winds present at high altitudes.
JETTISONING OF EXTERNAL STORES- Air©\
borne release of external stores; e.g., tiptanks,
ordnance.
(See FUEL DUMPING.)
(Refer to 14 CFR Part 91.)
JOINT USE RESTRICTED AREA(See RESTRICTED AREA.)
Pilot/Controller Glossary 2/14/08
PCG K-1
K
KNOWN TRAFFIC- With respect to ATC clear©\
ances, means aircraft whose altitude, position, and
intentions are known to ATC.
Pilot/Controller Glossary 2/14/08
PCG L-1
L
LAA(See LOCAL AIRPORT ADVISORY.)
LAAS(See LOW ALTITUDE ALERT SYSTEM.)
LAHSO- An acronym for ¡°Land and Hold Short
Operation.¡± These operations include landing and
holding short of an intersecting runway, a taxiway, a
predetermined point, or an approach/departure
flightpath.
LAHSO©\DRY- Land and hold short operations on
runways that are dry.
LAHSO©\WET- Land and hold short operations on
runways that are wet (but not contaminated).
LAND AND HOLD SHORT OPERATIONS -
Operations which include simultaneous takeoffs and
landings and/or simultaneous landings when a
landing aircraft is able and is instructed by the
controller to hold©\short of the intersecting runway/
taxiway or designated hold©\short point. Pilots are
expected to promptly inform the controller if the hold
short clearance cannot be accepted.
(See PARALLEL RUNWAYS.)
(Refer to AIM.)
LANDING AREA- Any locality either on land,
water, or structures, including airports/heliports and
intermediate landing fields, which is used, or
intended to be used, for the landing and takeoff of
aircraft whether or not facilities are provided for the
shelter, servicing, or for receiving or discharging
passengers or cargo.
(See ICAO term LANDING AREA.)
LANDING AREA [ICAO]- That part of a movement
area intended for the landing or take©\off of aircraft.
LANDING DIRECTION INDICATOR- A device
which visually indicates the direction in which
landings and takeoffs should be made.
(See TETRAHEDRON.)
(Refer to AIM.)
LANDING DISTANCE AVAILABLE [ICAO]- The
length of runway which is declared available and
suitable for the ground run of an aeroplane landing.
LANDING MINIMUMS- The minimum visibility
prescribed for landing a civil aircraft while using an
instrument approach procedure. The minimum
applies with other limitations set forth in 14 CFR
Part 91 with respect to the Minimum Descent
Altitude (MDA) or Decision Height (DH) prescribed
in the instrument approach procedures as follows:
a. Straight©\in landing minimums. A statement of
MDA and visibility, or DH and visibility, required for
a straight©\in landing on a specified runway, or
b. Circling minimums. A statement of MDA and
visibility required for the circle©\to©\land maneuver.
Note:Descent below the established MDA or DH is
not authorized during an approach unless the
aircraft is in a position from which a normal
approach to the runway of intended landing can be
made and adequate visual reference to required
visual cues is maintained.
(See CIRCLE©\TO©\LAND MANEUVER.)
(See DECISION HEIGHT.)
(See INSTRUMENT APPROACH
PROCEDURE.)
(See MINIMUM DESCENT ALTITUDE.)
(See STRAIGHT©\IN LANDING.)
(See VISIBILITY.)
(Refer to 14 CFR Part 91.)
LANDING ROLL- The distance from the point of
touchdown to the point where the aircraft can be
brought to a stop or exit the runway.
LANDING SEQUENCE- The order in which
aircraft are positioned for landing.
(See APPROACH SEQUENCE.)
LAST ASSIGNED ALTITUDE- The last altitude/
flight level assigned by ATC and acknowledged by
the pilot.
(See MAINTAIN.)
(Refer to 14 CFR Part 91.)
LATERAL NAVIGATION (LNAV)¨C A function of
area navigation (RNAV) equipment which calculates,
displays, and provides lateral guidance to a profile or
path.
LATERAL SEPARATION- The lateral spacing of
aircraft at the same altitude by requiring operation on
different routes or in different geographical locations.
(See SEPARATION.)
Pilot/Controller Glossary 2/14/08
PCG L-2
LDA(See LOCALIZER TYPE DIRECTIONAL AID.)
(See ICAO Term LANDING DISTANCE
AVAILABLE.)
LF(See LOW FREQUENCY.)
LIGHTED AIRPORT- An airport where runway and
obstruction lighting is available.
(See AIRPORT LIGHTING.)
(Refer to AIM.)
LIGHT GUN- A handheld directional light signaling
device which emits a brilliant narrow beam of white,
green, or red light as selected by the tower controller.
The color and type of light transmitted can be used to
approve or disapprove anticipated pilot actions where
radio communication is not available. The light gun
is used for controlling traffic operating in the vicinity
of the airport and on the airport movement area.
(Refer to AIM.)
LOCAL AIRPORT ADVISORY (LAA)- A service
provided by facilities, which are located on the
landing airport, have a discrete ground-to-air
communication frequency or the tower frequency
when the tower is closed, automated weather
reporting with voice broadcasting, and a continuous
ASOS/AWOS data display, other continuous direct
reading instruments, or manual observations avail©\
able to the specialist.
(See AIRPORT ADVISORY AREA.)
LOCAL TRAFFIC- Aircraft operating in the traffic
pattern or within sight of the tower, or aircraft known
to be departing or arriving from flight in local practice
areas, or aircraft executing practice instrument
approaches at the airport.
(See TRAFFIC PATTERN.)
LOCALIZER- The component of an ILS which
provides course guidance to the runway.
(See INSTRUMENT LANDING SYSTEM.)
(See ICAO term LOCALIZER COURSE.)
(Refer to AIM.)
LOCALIZER COURSE [ICAO]- The locus of
points, in any given horizontal plane, at which the
DDM (difference in depth of modulation) is zero.
LOCALIZER OFFSET- An angular offset of the
localizer from the runway extended centerline in a
direction away from the no transgression zone (NTZ)
that increases the normal operating zone (NOZ)
width. An offset requires a 50 foot increase in DH and
is not authorized for CAT II and CAT III approaches.
LOCALIZER TYPE DIRECTIONAL AID- A
NAVAID used for nonprecision instrument ap©\
proaches with utility and accuracy comparable to a
localizer but which is not a part of a complete ILS and
is not aligned with the runway.
(Refer to AIM.)
LOCALIZER USABLE DISTANCE- The maxi©\
mum distance from the localizer transmitter at a
specified altitude, as verified by flight inspection, at
which reliable course information is continuously
received.
(Refer to AIM.)
LOCATOR [ICAO]- An LM/MF NDB used as an aid
to final approach.
Note:A locator usually has an average radius of
rated coverage of between 18.5 and 46.3 km (10
and 25 NM).
LONG RANGE NAVIGATION(See LORAN.)
LONGITUDINAL SEPARATION- The longitudi©\
nal spacing of aircraft at the same altitude by a
minimum distance expressed in units of time or
miles.
(See SEPARATION.)
(Refer to AIM.)
LORAN- An electronic navigational system by
which hyperbolic lines of position are determined by
measuring the difference in the time of reception of
synchronized pulse signals from two fixed transmit©\
ters. Loran A operates in the 1750©\1950 kHz
frequency band. Loran C and D operate in the
100©\110 kHz frequency band.
(Refer to AIM.)
LOST COMMUNICATIONS- Loss of the ability to
communicate by radio. Aircraft are sometimes
referred to as NORDO (No Radio). Standard pilot
procedures are specified in 14 CFR Part 91. Radar
controllers issue procedures for pilots to follow in the
event of lost communications during a radar approach
when weather reports indicate that an aircraft will
likely encounter IFR weather conditions during the
approach.
(Refer to 14 CFR Part 91.)
(Refer AIM.)
Pilot/Controller Glossary 2/14/08
PCG L-3
LOW ALTITUDE AIRWAY STRUCTURE- The
network of airways serving aircraft operations up to
but not including 18,000 feet MSL.
(See AIRWAY.)
(Refer to AIM.)
LOW ALTITUDE ALERT, CHECK YOUR ALTI©\
TUDE IMMEDIATELY(See SAFETY ALERT.)
LOW ALTITUDE ALERT SYSTEM- An auto©\
mated function of the TPX©\42 that alerts the
controller when a Mode C transponder equipped
aircraft on an IFR flight plan is below a
predetermined minimum safe altitude. If requested
by the pilot, Low Altitude Alert System monitoring
is also available to VFR Mode C transponder
equipped aircraft.
LOW APPROACH- An approach over an airport or
runway following an instrument approach or a VFR
approach including the go©\around maneuver where
the pilot intentionally does not make contact with the
runway.
(Refer to AIM.)
LOW FREQUENCY- The frequency band between
30 and 300 kHz.
(Refer to AIM.)
LPV- A type of approach with vertical guidance
(APV) based on WAAS, published on RNAV (GPS)
approach charts. This procedure takes advantage of
the precise lateral guidance available from WAAS.
The minima is published as a decision altitude (DA).
Pilot/Controller Glossary 2/14/08
PCG M-1
M
MAA(See MAXIMUM AUTHORIZED ALTITUDE.)
MACH NUMBER- The ratio of true airspeed to the
speed of sound; e.g., MACH .82, MACH 1.6.
(See AIRSPEED.)
MACH TECHNIQUE [ICAO]- Describes a control
technique used by air traffic control whereby turbojet
aircraft operating successively along suitable routes
are cleared to maintain appropriate MACH numbers
for a relevant portion of the en route phase of flight.
The principle objective is to achieve improved
utilization of the airspace and to ensure that
separation between successive aircraft does not
decrease below the established minima.
MAHWP- Missed Approach Holding Waypoint
MAINTAINa. Concerning altitude/flight level, the term
means to remain at the altitude/flight level specified.
The phrase ¡°climb and¡± or ¡°descend and¡± normally
precedes ¡°maintain¡± and the altitude assignment;
e.g., ¡°descend and maintain 5,000.¡±
b. Concerning other ATC instructions, the term is
used in its literal sense; e.g., maintain VFR.
MAINTENANCE PLANNING FRICTION
LEVEL- The friction level specified in
AC 150/5320©\12, Measurement, Construction, and
Maintenance of Skid Resistant Airport Pavement
Surfaces, which represents the friction value below
which the runway pavem ent surface rem ains
acceptable for any category or class of aircraft
operations but which is beginning to show signs of
deterioration. This value will vary depending on the
particular friction measurement equipment used.
MAKE SHORT APPROACH- Used by ATC to
inform a pilot to alter his/her traffic pattern so as to
make a short final approach.
(See TRAFFIC PATTERN.)
MAN PORTABLE AIR DEFENSE SYSTEMS
(MANPADS)- MANPADS are lightweight, shoul©\
der-launched, missile systems used to bring down
aircraft and create mass casualties. The potential for
MANPADS use against airborne aircraft is real and
requires familiarity with the subject. Terrorists
choose MANPADS because the weapons are low
cost, highly mobile, require minimal set-up time, and
are easy to use and maintain. Although the weapons
have limited range, and their accuracy is affected by
poor visibility and adverse weather, they can be fired
from anywhere on land or from boats where there is
unrestricted visibility to the target.
MANDATORY ALTITUDE- An altitude depicted
on an instrument Approach Procedure Chart
requiring the aircraft to maintain altitude at the
depicted value.
MANPADS(See MAN PORTABLE AIR DEFENSE
SYSTEMS.)
MAP(See MISSED APPROACH POINT.)
MARKER BEACON- An electronic navigation
facility transmitting a 75 MHz vertical fan or
boneshaped radiation pattern. Marker beacons are
identified by their modulation frequency and keying
code, and when received by compatible airborne
equipment, indicate to the pilot, both aurally and
visually, that he/she is passing over the facility.
(See INNER MARKER.)
(See MIDDLE MARKER.)
(See OUTER MARKER.)
(Refer to AIM.)
MARSA(See MILITARY AUTHORITY ASSUMES
RESPONSIBILITY FOR SEPARATION OF
AIRCRAFT.)
MAWP- Missed Approach Waypoint
MAXIMUM AUTHORIZED ALTITUDE- A pub©\
lished altitude representing the maximum usable
altitude or flight level for an airspace structure or
route segment. It is the highest altitude on a Federal
airway, jet route, area navigation low or high route,
or other direct route for which an MEA is designated
in 14 CFR Part 95 at which adequate reception of
navigation aid signals is assured.
MAYDAY- The international radiotelephony distress
signal. When repeated three times, it indicates
Pilot/Controller Glossary 2/14/08
PCG M-2
imminent and grave danger and that immediate
assistance is requested.
(See PAN©\PAN.)
(Refer to AIM.)
MCA(See MINIMUM CROSSING ALTITUDE.)
MDA(See MINIMUM DESCENT ALTITUDE.)
MEA(See MINIMUM EN ROUTE IFR ALTITUDE.)
MEARTS(See MICRO©\EN ROUTE AUTOMATED RADAR
TRACKING SYSTEM.)
METEOROLOGICAL IMPACT STATEMENT-
An unscheduled planning forecast describing
conditions expected to begin within 4 to 12 hours
which may impact the flow of air traffic in a specific
center's (ARTCC) area.
METER FIX ARC- A semicircle, equidistant from
a meter fix, usually in low altitude relatively close to
the meter fix, used to help CTAS/HOST calculate a
meter time, and determine appropriate sector meter
list assignments for aircraft not on an established
arrival route or assigned a meter fix.
METER FIX TIME/SLOT TIME- A calculated time
to depart the meter fix in order to cross the vertex at
the ACLT. This time reflects descent speed
adjustment and any applicable time that must be
absorbed prior to crossing the meter fix.
METER LIST(See ARRIVAL SECTOR ADVISORY LIST.)
METER LIST DISPLAY INTERVAL- A dynamic
parameter which controls the number of minutes
prior to the flight plan calculated time of arrival at the
meter fix for each aircraft, at which time the TCLT is
frozen and becomes an ACLT; i.e., the VTA is
updated and consequently the TCLT modified as
appropriate until frozen at which time updating is
suspended and an ACLT is assigned. When frozen,
the flight entry is inserted into the arrival sector's
meter list for display on the sector PVD/MDM.
MLDI is used if filed true airspeed is less than or
equal to freeze speed parameters (FSPD).
METERING- A method of time©\regulating arrival
traffic flow into a terminal area so as not to exceed a
predetermined terminal acceptance rate.
METERING AIRPORTS- Airports adapted for
metering and for which optimum flight paths are
defined. A maximum of 15 airports may be adapted.
METERING FIX- A fix along an established route
from over which aircraft will be metered prior to
entering terminal airspace. Normally, this fix should
be established at a distance from the airport which
will facilitate a profile descent 10,000 feet above
airport elevation (AAE) or above.
METERING POSITION(S )- Adapted PVDs/
MDMs and associated ¡°D¡± positions eligible for
display of a metering position list. A maximum of
four PVDs/MDMs may be adapted.
METERING POSITION LIST- An ordered list of
data on arrivals for a selected metering airport
displayed on a metering position PVD/MDM.
MFT(See METER FIX TIME/SLOT TIME.)
MHA(See MINIMUM HOLDING ALTITUDE.)
MIA(See MINIMUM IFR ALTITUDES.)
MICROBURST- A small downburst with outbursts
of damaging winds extending 2.5 miles or less. In
spite of its small horizontal scale, an intense
microburst could induce wind speeds as high as 150
knots
(Refer to AIM.)
MIC RO©\EN ROUTE AUTOMATED RADAR
TRACKING SYSTEM (MEARTS)- An automated
radar and radar beacon tracking system capable of
employing both short©\range (ASR) and long©\range
(ARSR) radars. This microcomputer driven system
provides improved tracking, continuous data record©\
ing, and use of full digital radar displays.
MICROWAVE LANDING SYSTEM- A precision
instrument approach system operating in the
microwave spectrum which normally consists of the
following components:
a. Azimuth Station.
b. Elevation Station.
c. Precision Distance Measuring Equipment.
(See MLS CATEGORIES.)
MID RVR(See VISIBILITY.)
MIDDLE COMPASS LOCATOR(See COMPASS LOCATOR.)
Pilot/Controller Glossary 2/14/08
PCG M-3
MIDDLE MARKER- A marker beacon that defines
a point along the glideslope of an ILS normally
located at or near the point of decision height (ILS
Category I). It is keyed to transmit alternate dots and
dashes, with the alternate dots and dashes keyed at the
rate of 95 dot/dash combinations per minute on a
1300 Hz tone, which is received aurally and visually
by compatible airborne equipment.
(See INSTRUMENT LANDING SYSTEM.)
(See MARKER BEACON.)
(Refer to AIM.)
MILES©\IN©\TRAIL- A specified distance between
aircraft, normally, in the same stratum associated
with the same destination or route of flight.
MILITARY AUTHORITY ASSUMES RESPONSI©\
BILITY FOR SEPARATION OF AIRCRAFT- A
condition whereby the military services involved
assume responsibility for separation between
participating military aircraft in the ATC system. It is
used only for required IFR operations which are
specified in letters of agreement or other appropriate
FAA or military documents.
MILITARY LANDING ZONE- A landing strip used
exclusively by the military for training. A military
landing zone does not carry a runway designation.
MILITARY OPERATIONS AREA(See SPECIAL USE AIRSPACE.)
MILITARY TRAINING ROUTES- Airspace of
defined vertical and lateral dimensions established
for the conduct of military flight training at airspeeds
in excess of 250 knots IAS.
(See IFR MILITARY TRAINING ROUTES.)
(See VFR MILITARY TRAINING ROUTES.)
MINIMA(See MINIMUMS.)
MINIMUM CROSSING ALTITUDE- The lowest
altitude at certain fixes at which an aircraft must cross
when proceeding in the direction of a higher
minimum en route IFR altitude (MEA).
(See MINIMUM EN ROUTE IFR ALTITUDE.)
MINIMUM DESCENT ALTITUDE- The lowest
altitude, expressed in feet above mean sea level, to
which descent is authorized on final approach or
during circle©\to©\land maneuvering in execution of a
standard instrument approach procedure where no
electronic glideslope is provided.
(See NONPRECISION APPROACH
PROCEDURE.)
MINIMUM EN ROUTE IFR ALTITUDE (MEA)-
The lowest published altitude between radio fixes
which assures acceptable navigational signal cover©\
age and meets obstacle clearance requirements
between those fixes. The MEA prescribed for a
Federal airway or segment thereof, area navigation
low or high route, or other direct route applies to the
entire width of the airway, segment, or route between
the radio fixes defining the airway, segment, or route.
(Refer to 14 CFR Part 91.)
(Refer to 14 CFR Part 95.)
(Refer to AIM.)
MINIMUM FRICTION LEVEL- The friction level
specified in AC 150/5320©\12, Measurem ent,
Construction, and Maintenance of Skid Resistant
Airport Pavement Surfaces, that represents the
minimum recommended wet pavement surface
friction value for any turbojet aircraft engaged in
LAHSO. This value will vary with the particular
friction measurement equipment used.
MINIMUM FUEL- Indicates that an aircraft's fuel
supply has reached a state where, upon reaching the
destination, it can accept little or no delay. This is not
an emergency situation but merely indicates an
emergency situation is possible should any undue
delay occur.
(Refer to AIM.)
MINIMUM HOLDING ALTITUDE- The lowest
altitude prescribed for a holding pattern which
assures navigational signal coverage, communica©\
tions, and meets obstacle clearance requirements.
MINIMUM IFR ALTITUDES (MIA)- Minimum
altitudes for IFR operations as prescribed in 14 CFR
Part 91. These altitudes are published on aeronautical
charts and prescribed in 14 CFR Part 95 for airways
and routes, and in 14 CFR Part 97 for standard
instrument approach procedures. If no applicable
minimum altitude is prescribed in 14 CFR Part 95 or
14 CFR Part 97, the following minimum IFR
altitude applies:
a. In designated mountainous areas, 2,000 feet
above the highest obstacle within a horizontal
distance of 4 nautical miles from the course to be
flown; or
Pilot/Controller Glossary 2/14/08
PCG M-4
b. Other than mountainous areas, 1,000 feet above
the highest obstacle within a horizontal distance of 4
nautical miles from the course to be flown; or
c. As otherwise authorized by the Administrator
or assigned by ATC.
(See MINIMUM CROSSING ALTITUDE.)
(See MINIMUM EN ROUTE IFR ALTITUDE.)
(See MINIMUM OBSTRUCTION CLEARANCE
ALTITUDE.)
(See MINIMUM SAFE ALTITUDE.)
(See MINIMUM VECTORING ALTITUDE.)
(Refer to 14 CFR Part 91.)
MINIMUM NAVIGATION PERFORMANCE
SPECIFICATION- A set of standards which require
aircraft to have a minimum navigation performance
capability in order to operate in MNPS designated
airspace. In addition, aircraft must be certified by
their State of Registry for MNPS operation.
MINIMUM NAVIGATION PERFORMANCE
SPECIFICATION AIRSPACE- Designated airspace
in which MNPS procedures are applied between
MNPS certified and equipped aircraft. Under certain
conditions, non©\MNPS aircraft can operate in
MNPSA. However, standard oceanic separation
minima is provided between the non©\MNPS aircraft
and other traffic. Currently, the only designated
MNPSA is described as follows:
a. Between FL 285 and FL 420;
b. Between latitudes 27N and the North Pole;
c. In the east, the eastern boundaries of the CTAs
Santa Maria Oceanic, Shanwick Oceanic, and
Reykjavik;
d. In the west, the western boundaries of CTAs
Reykjavik and Gander Oceanic and New York
Oceanic excluding the area west of 60W and south
of 3830'N.
MINIMUM OBSTRUCTION CLEARANCE ALTI©\
TUDE (MOCA)- The lowest published altitude in
effect between radio fixes on VOR airways,
off©\airway routes, or route segments which meets
obstacle clearance requirements for the entire route
segment and which assures acceptable navigational
signal coverage only within 25 statute (22 nautical)
miles of a VOR.
(Refer to 14 CFR Part 91.)
(Refer to 14 CFR Part 95.)
MINIMUM RECEPTION ALTITUDE- The lowest
altitude at which an intersection can be determined.
(Refer to 14 CFR Part 95.)
MINIMUM SAFE ALTITUDEa. The minimum altitude specified in 14 CFR
Part 91 for various aircraft operations.
b. Altitudes depicted on approach charts which
provide at least 1,000 feet of obstacle clearance for
emergency use within a specified distance from the
navigation facility upon which a procedure is
predicated. These altitudes will be identified as
Minimum Sector Altitudes or Emergency Safe
Altitudes and are established as follows:
1. Minimum Sector Altitudes. Altitudes de©\
picted on approach charts which provide at least
1,000 feet of obstacle clearance within a 25©\mile
radius of the navigation facility upon which the
procedure is predicated. Sectors depicted on
approach charts must be at least 90 degrees in scope.
These altitudes are for emergency use only and do not
necessarily assure acceptable navigational signal
coverage.
(See ICAO term Minimum Sector Altitude.)
2. Emergency Safe Altitudes. Altitudes de©\
picted on approach charts which provide at least
1,000 feet of obstacle clearance in nonmountainous
areas and 2,000 feet of obstacle clearance in
designated mountainous areas within a 100©\mile
radius of the navigation facility upon which the
procedure is predicated and normally used only in
military procedures. These altitudes are identified on
published procedures as ¡°Emergency Safe Alti©\
tudes.¡±
MINIMUM SAFE ALTITUDE WARNING- A
function of the ARTS III computer that aids the
controller by alerting him/her when a tracked Mode
C equipped aircraft is below or is predicted by the
computer to go below a predetermined minimum safe
altitude.
(Refer to AIM.)
MINIMUM SECTOR ALTITUDE [ICAO]- The
lowest altitude which may be used under emergency
conditions which will provide a minimum clearance
of 300 m (1,000 feet) above all obstacles located in
an area contained within a sector of a circle of 46 km
(25 NM) radius centered on a radio aid to navigation.
MINIMUMS- Weather condition requirements
established for a particular operation or type of
Pilot/Controller Glossary 2/14/08
PCG M-5
operation; e.g., IFR takeoff or landing, alternate
airport for IFR flight plans, VFR flight, etc.
(See IFR CONDITIONS.)
(See IFR TAKEOFF MINIMUMS AND
DEPARTURE PROCEDURES.)
(See LANDING MINIMUMS.)
(See VFR CONDITIONS.)
(Refer to 14 CFR Part 91.)
(Refer to AIM.)
MINIMUM VECTORING ALTITUDE (MVA)-
The lowest MSL altitude at which an IFR aircraft will
be vectored by a radar controller, except as otherwise
authorized for radar approaches, departures, and
missed approaches. The altitude meets IFR obstacle
clearance criteria. It may be lower than the published
MEA along an airway or J©\route segment. It may be
utilized for radar vectoring only upon the controller's
determination that an adequate radar return is being
received from the aircraft being controlled. Charts
depicting minimum vectoring altitudes are normally
available only to the controllers and not to pilots.
(Refer to AIM.)
MINUTES©\IN©\TRAIL- A specified interval be©\
tween aircraft expressed in time. This method would
more likely be utilized regardless of altitude.
MIS(See METEOROLOGICAL IMPACT
STATEMENT.)
MISSED APPROACH-
a. A maneuver conducted by a pilot when an
instrument approach cannot be completed to a
landing. The route of flight and altitude are shown on
instrument approach procedure charts. A pilot
executing a missed approach prior to the Missed
Approach Point (MAP) must continue along the final
approach to the MAP.
b. A term used by the pilot to inform ATC that
he/she is executing the missed approach.
c. At locations where ATC radar service is
provided, the pilot should conform to radar vectors
when provided by ATC in lieu of the published
missed approach procedure.
(See MISSED APPROACH POINT.)
(Refer to AIM.)
MISSED APPROACH POINT- A point prescribed
in each instrument approach procedure at which a
missed approach procedure shall be executed if the
required visual reference does not exist.
(See MISSED APPROACH.)
(See SEGMENTS OF AN INSTRUMENT
APPROACH PROCEDURE.)
MISSED APPROACH PROCEDURE [ICAO]- The
procedure to be followed if the approach cannot be
continued.
MISSED APPROACH SEGMENT(See SEGMENTS OF AN INSTRUMENT
APPROACH PROCEDURE.)
MLDI(See METER LIST DISPLAY INTERVAL.)
MLS(See MICROWAVE LANDING SYSTEM.)
MLS CATEGORIESa. MLS Category I. An MLS approach procedure
which provides for an approach to a height above
touchdown of not less than 200 feet and a runway
visual range of not less than 1,800 feet.
b. MLS Category II. Undefined until data gather©\
ing/analysis completion.
c. MLS Category III. Undefined until data
gathering/analysis completion.
MM(See MIDDLE MARKER.)
MNPS(See MINIMUM NAVIGATION PERFORMANCE
SPECIFICATION.)
MNPSA(See MINIMUM NAVIGATION PERFORMANCE-
SPECIFICATION AIRSPACE.)
MOA(See MILITARY OPERATIONS AREA.)
MOCA(See MINIMUM OBSTRUCTION CLEARANCE
ALTITUDE.)
MODE- The letter or number assigned to a specific
pulse spacing of radio signals transmitted or received
by ground interrogator or airborne transponder
components of the Air Traffic Control Radar Beacon
Pilot/Controller Glossary 2/14/08
PCG M-6
System (ATCRBS). Mode A (military Mode 3) and
Mode C (altitude reporting) are used in air traffic
control.
(See INTERROGATOR.)
(See RADAR.)
(See TRANSPONDER.)
(See ICAO term MODE.)
(Refer to AIM.)
MODE (SSR MODE) [ICAO]- The letter or number
assigned to a specific pulse spacing of the
interrogation signals transmitted by an interrogator.
There are 4 modes, A, B, C and D specified in Annex
10, corresponding to four different interrogation
pulse spacings.
MODE C INTRUDER ALERT- A function of
certain air traffic control automated systems designed
to alert radar controllers to existing or pending
situations between a tracked target (known IFR or
VFR aircraft) and an untracked target (unknown IFR
or VFR aircraft) that requires immediate attention/
action.
(See CONFLICT ALERT.)
MONITOR- (When used with communication
transfer) listen on a specific frequency and stand by
for instructions. Under normal circumstances do not
establish communications.
MONITOR ALERT (MA)- A function of the ETMS
that provides traffic management personnel with a
tool for predicting potential capacity problems in
individual operational sectors. The MA is an
indication that traffic management personnel need to
analyze a particular sector for actual activity and to
determine the required action(s), if any, needed to
control the demand.
MONITOR ALERT PARAMETER (MAP)- The
number designated for use in monitor alert
processing by the ETMS. The MAP is designated for
each operational sector for increments of 15 minutes.
MOSAIC/MULTI-SENSOR MODE- Accepts posi©\
tional data from multiple radar or ADS-B sites.
Targets are displayed from a single source within a
radar sort box according to the hierarchy of the
sources assigned.
MOVEMENT AREA- The runways, taxiways, and
other areas of an airport/heliport which are utilized
for taxiing/hover taxiing, air taxiing, takeoff, and
landing of aircraft, exclusive of loading ramps and
parking areas. At those airports/heliports with a
tower, specific approval for entry onto the movement
area must be obtained from ATC.
(See ICAO term MOVEMENT AREA.)
MOVEMENT AREA [ICAO]- That part of an
aerodrome to be used for the takeoff, landing and
taxiing of aircraft, consisting of the maneuvering area
and the apron(s).
MOVING TARGET INDICATOR- An electronic
device which will permit radar scope presentation
only from targets which are in motion. A partial
remedy for ground clutter.
MRA(See MINIMUM RECEPTION ALTITUDE.)
MSA(See MINIMUM SAFE ALTITUDE.)
MSAW(See MINIMUM SAFE ALTITUDE WARNING.)
MTI(See MOVING TARGET INDICATOR.)
MTR(See MILITARY TRAINING ROUTES.)
MULTICOM- A mobile service not open to public
correspondence used to provide communications
essential to conduct the activities being performed by
or directed from private aircraft.
MULTIPLE RUNWAYS- The utilization of a
dedicated arrival runway(s) for departures and a
dedicated departure runway(s) for arrivals when
feasible to reduce delays and enhance capacity.
MVA(See MINIMUM VECTORING ALTITUDE.)
Pilot/Controller Glossary 2/14/08
PCG N-1
N
NAS(See NATIONAL AIRSPACE SYSTEM.)
NATIONAL AIRSPACE SYSTEM- The common
network of U.S. airspace; air navigation facilities,
equipment and services, airports or landing areas;
aeronautical charts, information and services; rules,
regulations and procedures, technical information,
and manpower and material. Included are system
components shared jointly with the military.
NATIONAL BEACON CODE ALLOCATION
PLAN AIRSPACE- Airspace over United States
territory located within the North American continent
between Canada and Mexico, including adjacent
territorial waters outward to about boundaries of
oceanic control areas (CTA)/Flight Information
Regions (FIR).
(See FLIGHT INFORMATION REGION.)
NATIONAL FLIGHT DATA CENTER- A facility in
Washington D.C., established by FAA to operate a
central aeronautical information service for the
collection, validation, and dissemination of aeronau©\
tical data in support of the activities of government,
industry, and the aviation community. The informa©\
tion is published in the National Flight Data Digest.
(See NATIONAL FLIGHT DATA DIGEST.)
NATIONAL FLIGHT DATA DIGEST- A daily
(except weekends and Federal holidays) publication
of flight information appropriate to aeronautical
charts, aeronautical publications, Notices to Airmen,
or other media serving the purpose of providing
operational flight data essential to safe and efficient
aircraft operations.
NATIONAL SEARCH AND RESCUE PLAN- An
interagency agreement which provides for the
effective utilization of all available facilities in all
types of search and rescue missions.
NAVAID(See NAVIGATIONAL AID.)
NAVAID CLASSES- VOR, VORTAC, and TACAN
aids are classed according to their operational use.
The three classes of NAVAIDs are:
a. T- Terminal.
b. L- Low altitude.
c. H- High altitude.
Note:The normal service range for T, L, and H class
aids is found in the AIM. Certain operational
requirements make it necessary to use some of
these aids at greater service ranges than
specified. Extended range is made possible
through flight inspection determinations. Some
aids also have lesser service range due to location,
terrain, frequency protection, etc. Restrictions to
service range are listed in Airport/Facility
Directory.
NAVIGABLE AIRSPACE- Airspace at and above
the minimum flight altitudes prescribed in the CFRs
including airspace needed for safe takeoff and
landing.
(Refer to 14 CFR Part 91.)
NAVIGATION REFERENCE SYSTEM (NRS)-
The NRS is a system of waypoints developed for use
within the United States for flight planning and
navigation without reference to ground based
navigational aids. The NRS waypoints are located in
a grid pattern along defined latitude and longitude
lines. The initial use of the NRS will be in the high
altitude environment in conjunction with the High
Altitude Redesign initiative. The NRS waypoints are
intended for use by aircraft capable of point-to-point
navigation.
NAVIGATIONAL AID- Any visual or electronic
device airborne or on the surface which provides
point©\to©\point guidance information or position data
to aircraft in flight.
(See AIR NAVIGATION FACILITY.)
NBCAP AIRSPACE(See NATIONAL BEACON CODE ALLOCATION
PLAN AIRSPACE.)
NDB(See NONDIRECTIONAL BEACON.)
NEGATIVE- ¡°No,¡± or ¡°permission not granted,¡± or
¡°that is not correct.¡±
NEGATIVE CONTACT- Used by pilots to inform
ATC that:
a. Previously issued traffic is not in sight. It may
be followed by the pilot's request for the controller to
provide assistance in avoiding the traffic.
b. They were unable to contact ATC on a
particular frequency.
Pilot/Controller Glossary 2/14/08
PCG N-2
NFDC(See NATIONAL FLIGHT DATA CENTER.)
NFDD(See NATIONAL FLIGHT DATA DIGEST.)
NIGHT- The time between the end of evening civil
twilight and the beginning of morning civil twilight,
as published in the American Air Almanac, converted
to local time.
(See ICAO term NIGHT.)
NIGHT [ICAO]- The hours between the end of
evening civil twilight and the beginning of morning
civil twilight or such other period between sunset and
sunrise as may be specified by the appropriate
authority.
Note:Civil twilight ends in the evening when the
center of the sun's disk is 6 degrees below the
horizon and begins in the morning when the center
of the sun's disk is 6 degrees below the horizon.
NO GYRO APPROACH- A radar approach/vector
provided in case of a malfunctioning gyro©\compass
or directional gyro. Instead of providing the pilot
with headings to be flown, the controller observes the
radar track and issues control instructions ¡°turn
right/left¡± or ¡°stop turn¡± as appropriate.
(Refer to AIM.)
NO GYRO VECTOR(See NO GYRO APPROACH.)
NO TRANSGRESSION ZONE (NTZ)- The NTZ is
a 2,000 foot wide zone, located equidistant between
parallel runway final approach courses in which
flight is not allowed.
NONAPPROACH CONTROL TOWER- Author©\
izes aircraft to land or takeoff at the airport controlled
by the tower or to transit the Class D airspace. The
primary function of a nonapproach control tower is
the sequencing of aircraft in the traffic pattern and on
the landing area. Nonapproach control towers also
separate aircraft operating under instrument flight
rules clearances from approach controls and centers.
They provide ground control services to aircraft,
vehicles, personnel, and equipment on the airport
movement area.
NONCOMMON ROUTE/PORTION- That segment
of a North American Route between the inland
navigation facility and a designated North American
terminal.
NONCOMPOSITE SEPARATION- Separation in
accordance with minima other than the composite
separation minimum specified for the area con©\
cerned.
NONDIRECTIONAL BEACON- An L/MF or UHF
radio beacon transmitting nondirectional signals
whereby the pilot of an aircraft equipped with
direction finding equipment can determine his/her
bearing to or from the radio beacon and ¡°home¡± on or
track to or from the station. When the radio beacon is
installed in conjunction with the Instrument Landing
System marker, it is normally called a Compass
Locator.
(See AUTOMATIC DIRECTION FINDER.)
(See COMPASS LOCATOR.)
NONMOVEMENT AREAS- Taxiways and apron
(ramp) areas not under the control of air traffic.
NONPRECISION APPROACH(See NONPRECISION APPROACH
PROCEDURE.)
NONPRECISION APPROACH PROCEDURE- A
standard instrument approach procedure in which no
electronic glideslope is provided; e.g., VOR,
TACAN, NDB, LOC, ASR, LDA, or SDF
approaches.
NONRADAR- Precedes other terms and generally
means without the use of radar, such as:
a. Nonradar Approach. Used to describe instru©\
ment approaches for which course guidance on final
approach is not provided by ground©\based precision
or surveillance radar. Radar vectors to the final
approach course may or may not be provided by ATC.
Examples of nonradar approaches are VOR, NDB,
TACAN, and ILS/MLS approaches.
(See FINAL APPROACH COURSE.)
(See FINAL APPROACH©\IFR.)
(See INSTRUMENT APPROACH
PROCEDURE.)
(See RADAR APPROACH.)
b. Nonradar Approach Control. An ATC facility
providing approach control service without the use of
radar.
(See APPROACH CONTROL FACILITY.)
(See APPROACH CONTROL SERVICE.)
c. Nonradar Arrival. An aircraft arriving at an
airport without radar service or at an airport served by
a radar facility and radar contact has not been
Pilot/Controller Glossary 2/14/08
PCG N-3
established or has been terminated due to a lack of
radar service to the airport.
(See RADAR ARRIVAL.)
(See RADAR SERVICE.)
d. Nonradar Route. A flight path or route over
which the pilot is performing his/her own navigation.
The pilot may be receiving radar separation, radar
monitoring, or other ATC services while on a
nonradar route.
(See RADAR ROUTE.)
e. Nonradar Separation. The spacing of aircraft in
accordance with established minima without the use
of radar; e.g., vertical, lateral, or longitudinal
separation.
(See RADAR SEPARATION.)
(See ICAO term NONRADAR SEPARATION.)
NONRADAR SEPARATION [ICAO]- The separa©\
tion used when aircraft position information is
derived from sources other than radar.
NON-RESTRICTIVE ROUTING (NRR)- Portions
of a proposed route of flight where a user can flight
plan the most advantageous flight path with no
requirement to make reference to ground-based
NAVAIDs.
NOPAC(See NORTH PACIFIC.)
NORDO(See LOST COMMUNICATIONS.)
NORMAL OPERATING ZONE (NOZ)- The NOZ
is the operating zone within which aircraft flight
remains during normal independent simultaneous
parallel ILS approaches.
NORTH AMERICAN ROUTE- A numerically
coded route preplanned over existing airway and
route systems to and from specific coastal fixes
serving the North Atlantic. North American Routes
consist of the following:
a. Common Route/Portion. That segment of a
North American Route between the inland navigation
facility and the coastal fix.
b. Noncommon Route/Portion. That segment of a
North American Route between the inland navigation
facility and a designated North American terminal.
c. Inland Navigation Facility. A navigation aid on
a North American Route at which the common route
and/or the noncommon route begins or ends.
d. Coastal Fix. A navigation aid or intersection
where an aircraft transitions between the domestic
route structure and the oceanic route structure.
NORTH AMERICAN ROUTE PROGRAM (NRP)-
The NRP is a set of rules and procedures which are
designed to increase the flexibility of user flight
planning within published guidelines.
NORTH MARK- A beacon data block sent by the
host computer to be displayed by the ARTS on a 360
degree bearing at a locally selected radar azimuth and
distance. The North Mark is used to ensure correct
range/azimuth orientation during periods of
CENRAP.
NORTH PACIFIC- An organized route system
between the Alaskan west coast and Japan.
NOTAM(See NOTICE TO AIRMEN.)
NOTAM [ICAO]- A notice containing information
concerning the establishment, condition or change in
any aeronautical facility, service, procedure or
hazard, the timely knowledge of which is essential to
personnel concerned with flight operations.
a. I Distribution- Distribution by means of
telecommunication.
b. II Distribution- Distribution by means other
than telecommunications.
NOTIC E TO AIR MEN- A notice containing
information (not known sufficiently in advance to
publicize by other means) concerning the establish©\
ment, condition, or change in any component
(facility, service, or procedure of, or hazard in the
National Airspace System) the timely knowledge of
which is essential to personnel concerned with flight
operations.
a. NOTAM(D)- A NOTAM given (in addition to
local dissemination) distant dissemination beyond
the area of responsibility of the Flight Service
Station. These NOTAMs will be stored and available
until canceled.
b. NOTAM(L)- A NOTAM given local disse©\
mination by voice and other means, such as
telautograph and telephone, to satisfy local user
requirements.
c. FDC NOTAM- A NOTAM regulatory in
nature, transmitted by USNOF and given system
wide dissemination.
(See ICAO term NOTAM.)
Pilot/Controller Glossary 2/14/08
PCG N-4
NOTIC ES TO AIR MEN PUBLIC ATION- A
publication issued every 28 days, designed primarily
for the pilot, which contains current NOTAM
information considered essential to the safety of
flight as well as supplem ental data to other
aeronautical publications. The contraction NTAP is
used in NOTAM text.
(See NOTICE TO AIRMEN.)
NRR(See NON-RESTRICTIVE ROUTING.)
NRS(See NAVIGATION REFERENCE SYSTEM.)
NTAP(See NOTICES TO AIRMEN PUBLICATION.)
NUMEROUS TARGETS VICINITY (LOCA©\
TION)- A traffic advisory issued by ATC to advise
pilots that targets on the radar scope are too numerous
to issue individually.
(See TRAFFIC ADVISORIES.)
Pilot/Controller Glossary 2/14/08
PCG O-1
O
OBSTACLE- An existing object, object of natural
growth, or terrain at a fixed geographical location or
which may be expected at a fixed location within a
prescribed area with reference to which vertical
clearance is or must be provided during flight
operation.
OBSTACLE DEPARTURE PROCEDURE (ODP)-
A preplanned instrument flight rule (IFR) departure
procedure printed for pilot use in textual or graphic
form to provide obstruction clearance via the least
onerous route from the term inal area to the
appropriate en route structure. ODPs are recom©\
mended for obstruction clearance and may be flown
without ATC clearance unless an alternate departure
procedure (SID or radar vector) has been specifically
assigned by ATC.
(See IFR TAKEOFF MINIMUMS AND
DEPARTURE PROCEDURES.)
(See STANDARD INSTRUMENT
DEPARTURES.)
(Refer to AIM.)
OBSTACLE FREE ZONE- The OFZ is a three
dimensional volume of airspace which protects for
the transition of aircraft to and from the runway. The
OFZ clearing standard precludes taxiing and parked
airplanes and object penetrations, except for
frangible NAVAID locations that are fixed by
function. Additionally, vehicles, equipment, and
personnel may be authorized by air traffic control to
enter the area using the provisions of FAAO JO
7110.65, Para 3-1-5, VEHICLES/EQUIPMENT/
PERSONNEL ON RUNWAYS. The runway OFZ
and when applicable, the inner©\approach OFZ, and
the inner©\transitional OFZ, comprise the OFZ.
a. Runway OFZ. The runway OFZ is a defined
volume of airspace centered above the runway. The
runway OFZ is the airspace above a surface whose
elevation at any point is the same as the elevation of
the nearest point on the runway centerline. The
runway OFZ extends 200 feet beyond each end of the
runway. The width is as follows:
1. For runways serving large airplanes, the
greater of:
(a) 400 feet, or
(b) 180 feet, plus the wingspan of the most
demanding airplane, plus 20 feet per 1,000 feet of
airport elevation.
2. For runways serving only small airplanes:
(a) 300 feet for precision instrument run©\
ways.
(b) 250 feet for other runways serving small
airplanes with approach speeds of 50 knots, or more.
(c) 120 feet for other runways serving small
airplanes with approach speeds of less than 50 knots.
b. Inner©\approach OFZ. The inner©\approach OFZ
is a defined volume of airspace centered on the
approach area. The inner©\approach OFZ applies only
to runways with an approach lighting system. The
inner©\approach OFZ begins 200 feet from the runway
threshold at the same elevation as the runway
threshold and extends 200 feet beyond the last light
unit in the approach lighting system. The width of the
inner©\approach OFZ is the same as the runway OFZ
and rises at a slope of 50 (horizontal) to 1 (vertical)
from the beginning.
c. Inner©\transitional OFZ. The inner transitional
surface OFZ is a defined volume of airspace along the
sides of the runway and inner©\approach OFZ and
applies only to precision instrument runways. The
inner©\transitional surface OFZ slopes 3 (horizontal)
to 1 (vertical) out from the edges of the runway OFZ
and inner©\approach OFZ to a height of 150 feet above
the established airport elevation.
(Refer to AC 150/5300©\13, Chapter 3.)
(Refer to FAAO JO 7110.65, Para 3-1-5,
VEHICLES/EQUIPMENT/PERSONNEL ON
RUNWAYS.)
OBSTRUCTION- Any object/obstacle exceeding
the obstruction standards specified by 14 CFR
Part 77, Subpart C.
OBSTRUCTION LIGHT- A light or one of a group
of lights, usually red or white, frequently mounted on
a surface structure or natural terrain to warn pilots of
the presence of an obstruction.
OCEANIC AIRSPACE- Airspace over the oceans of
the world, considered international airspace, where
oceanic separation and procedures per the Interna©\
tional Civil Aviation Organization are applied.
Responsibility for the provisions of air traffic control
Pilot/Controller Glossary 2/14/08
PCG O-2
service in this airspace is delegated to various
countries, based generally upon geographic proximi©\
ty and the availability of the required resources.
OCEANIC DISPLAY AND PLANNING SYS©\
TEM- An automated digital display system which
provides flight data processing, conflict probe, and
situation display for oceanic air traffic control.
OCEANIC NAVIGATIONAL ERROR REPORT- A
report filed when an aircraft exiting oceanic airspace
has been observed by radar to be off course. ONER
reporting parameters and procedures are contained in
FAAO 7110.82, Monitoring of Navigational Perfor©\
mance In Oceanic Areas.
OCEANIC PUBLISHED ROUTE- A route estab©\
lished in international airspace and charted or
described in flight information publications, such as
Route Charts, DOD Enroute Charts, Chart Supple©\
ments, NOTAMs, and Track Messages.
OCEANIC TRANSITION ROUTE- An ATS route
established for the purpose of transitioning aircraft
to/from an organized track system.
ODAPS(See OCEANIC DISPLAY AND PLANNING
SYSTEM.)
ODP(See OBSTACLE DEPARTURE PROCEDURE.)
OFF COURSE- A term used to describe a situation
where an aircraft has reported a position fix or is
observed on radar at a point not on the ATC©\approved
route of flight.
OFF©\ROUTE VECTOR- A vector by ATC which
takes an aircraft off a previously assigned route.
Altitudes assigned by ATC during such vectors
provide required obstacle clearance.
OFFSET PARALLEL RUNWAYS- Staggered
runways having centerlines which are parallel.
OFFSHORE/CONTROL AIRSPACE AREA- That
portion of airspace between the U.S. 12 NM limit and
the oceanic CTA/FIR boundary within which air
traffic control is exercised. These areas are
established to provide air traffic control services.
Offshore/Control Airspace Areas may be classified
as either Class A airspace or Class E airspace.
OFT(See OUTER FIX TIME.)
OM(See OUTER MARKER.)
OMEGA- An RNAV system designed for long©\range
navigation based upon ground©\based electronic
navigational aid signals.
ON COURSEa. Used to indicate that an aircraft is established on
the route centerline.
b. Used by ATC to advise a pilot making a radar
approach that his/her aircraft is lined up on the final
approach course.
(See ON©\COURSE INDICATION.)
ON©\COURSE INDICATION- An indication on an
instrument, which provides the pilot a visual means
of determining that the aircraft is located on the
centerline of a given navigational track, or an
indication on a radar scope that an aircraft is on a
given track.
ONE©\MINUTE WEATHER- The most recent one
minute updated weather broadcast received by a pilot
from an uncontrolled airport ASOS/AWOS.
ONER(See OCEANIC NAVIGATIONAL ERROR
REPORT.)
OPERATIONAL(See DUE REGARD.)
OPPOSITE DIRECTION AIRCRAFT- Aircraft are
operating in opposite directions when:
a. They are following the same track in reciprocal
directions; or
b. Their tracks are parallel and the aircraft are
flying in reciprocal directions; or
c. Their tracks intersect at an angle of more than
135.
OPTION APPROACH- An approach requested and
conducted by a pilot which will result in either a
touch©\and©\go, missed approach, low approach,
stop©\and©\go, or full stop landing.
(See CLEARED FOR THE OPTION.)
(Refer to AIM.)
ORGANIZED TRACK SYSTEM- A series of ATS
routes which are fixed and charted; i.e., CEP,
NOPAC, or flexible and described by NOTAM; i.e.,
NAT TRACK MESSAGE.
OROCA- An off©\route altitude which provides
obstruction clearance with a 1,000 foot buffer in
Pilot/Controller Glossary 2/14/08
PCG O-3
nonmountainous terrain areas and a 2,000 foot buffer
in designated mountainous areas within the United
States. This altitude may not provide signal coverage
from ground©\based navigational aids, air traffic
control radar, or communications coverage.
OTR(See OCEANIC TRANSITION ROUTE.)
OTS(See ORGANIZED TRACK SYSTEM.)
OUT- The conversation is ended and no response is
expected.
OUTER AREA (associated with Class C airspace)-
Nonregulatory airspace surrounding designated
Class C airspace airports wherein ATC provides radar
vectoring and sequencing on a full©\time basis for all
IFR and participating VFR aircraft. The service
provided in the outer area is called Class C service
which includes: IFR/IFR-standard IFR separation;
IFR/VFR-traffic advisories and conflict resolution;
and VFR/VFR-traffic advisories and, as appropriate,
safety alerts. The normal radius will be 20 nautical
miles with some variations based on site©\specific
requirements. The outer area extends outward from
the primary Class C airspace airport and extends from
the lower limits of radar/radio coverage up to the
ceiling of the approach control's delegated airspace
excluding the Class C charted area and other airspace
as appropriate.
(See CONFLICT RESOLUTION.)
(See CONTROLLED AIRSPACE.)
OUTER COMPASS LOCATOR(See COMPASS LOCATOR.)
OUTER FIX- A general term used within ATC to
describe fixes in the terminal area, other than the final
approach fix. Aircraft are normally cleared to these
fixes by an Air Route Traffic Control Center or an
Approach Control Facility. Aircraft are normally
cleared from these fixes to the final approach fix or
final approach course.
OR
OUTER FIX- An adapted fix along the converted
route of flight, prior to the meter fix, for which
crossing times are calculated and displayed in the
metering position list.
OUTER FIX ARC- A semicircle, usually about a
50-70 mile radius from a meter fix, usually in high
altitude, which is used by CTAS/HOST to calculate
outer fix times and determine appropriate sector
meter list assignments for aircraft on an established
arrival route that will traverse the arc.
OUTER FIX TIME- A calculated time to depart the
outer fix in order to cross the vertex at the ACLT. The
time reflects descent speed adjustments and any
applicable delay time that must be absorbed prior to
crossing the meter fix.
OUTER MARKER- A marker beacon at or near the
glideslope intercept altitude of an ILS approach. It is
keyed to transmit two dashes per second on a 400 Hz
tone, which is received aurally and visually by
compatible airborne equipment. The OM is normally
located four to seven miles from the runway threshold
on the extended centerline of the runway.
(See INSTRUMENT LANDING SYSTEM.)
(See MARKER BEACON.)
(Refer to AIM.)
OVER- My transmission is ended; I expect a
response.
OVERHEAD MANEUVER- A series of predeter©\
mined maneuvers prescribed for aircraft (often in
formation) for entry into the visual flight rules (VFR)
traffic pattern and to proceed to a landing. An
overhead maneuver is not an instrument flight rules
(IFR) approach procedure. An aircraft executing an
overhead maneuver is considered VFR and the IFR
flight plan is cancelled when the aircraft reaches the
¡°initial point¡± on the initial approach portion of the
maneuver. The pattern usually specifies the
following:
a. The radio contact required of the pilot.
b. The speed to be maintained.
c. An initial approach 3 to 5 miles in length.
d. An elliptical pattern consisting of two 180
degree turns.
e. A break point at which the first 180 degree turn
is started.
f. The direction of turns.
g. Altitude (at least 500 feet above the convention©\
al pattern).
h. A ¡°Roll©\out¡± on final approach not less than 1/4
mile from the landing threshold and not less than 300
feet above the ground.
Pilot/Controller Glossary 2/14/08
PCG O-4
OVERLYING CENTER- The ARTCC facility that
is responsible for arrival/departure operations at a
specific terminal.
Pilot/Controller Glossary 2/14/08
PCG P-1
P
P TIME(See PROPOSED DEPARTURE TIME.)
P©\ACP(See PREARRANGED COORDINATION
PROCEDURES.)
PAN©\PAN- The international radio©\telephony urgen©\
cy signal. When repeated three times, indicates
uncertainty or alert followed by the nature of the
urgency.
(See MAYDAY.)
(Refer to AIM.)
PAR(See PRECISION APPROACH RADAR.)
PAR [ICAO]-
(See ICAO Term PRECISION APPROACH
RADAR.)
PARALLEL ILS APPROACHES- Approaches to
parallel runways by IFR aircraft which, when
established inbound toward the airport on the
adjacent final approach courses, are radar©\separated
by at least 2 miles.
(See FINAL APPROACH COURSE.)
(See SIMULTANEOUS ILS APPROACHES.)
PARALLEL MLS APPROACHES(See PARALLEL ILS APPROACHES.)
PARALLEL OFFSET ROUTE- A parallel track to
the left or right of the designated or established
airway/route. Normally associated with Area Navi©\
gation (RNAV) operations.
(See AREA NAVIGATION.)
PARALLEL RUNWAYS- Two or more runways at
the same airport whose centerlines are parallel. In
addition to runway number, parallel runways are
designated as L (left) and R (right) or, if three parallel
runways exist, L (left), C (center), and R (right).
PBCT(See PROPOSED BOUNDARY CROSSING
TIME.)
PDC(See PRE-DEPARTURE CLEARANCE.)
PERMANENT ECHO- Radar signals reflected from
fixed objects on the earth's surface; e.g., buildings,
towers, terrain. Permanent echoes are distinguished
from ¡°ground clutter¡± by being definable locations
rather than large areas. Under certain conditions they
may be used to check radar alignment.
PHOTO RECONNAISSANCE- Military activity
that requires locating individual photo targets and
navigating to the targets at a preplanned angle and
altitude. The activity normally requires a lateral route
width of 16 NM and altitude range of 1,500 feet to
10,000 feet AGL.
PILOT BRIEFING- A service provided by the FSS
to assist pilots in flight planning. Briefing items may
include weather information, NOTAMS, military
activities, flow control information, and other items
as requested.
(Refer to AIM.)
PILOT IN COMMAND- The pilot responsible for
the operation and safety of an aircraft during flight
time.
(Refer to 14 CFR Part 91.)
PILOT WEATHER REPORT- A report of meteoro©\
logical phenomena encountered by aircraft in flight.
(Refer to AIM.)
PILOT'S DISCRETION- When used in conjunc©\
tion with altitude assignments, means that ATC has
offered the pilot the option of starting climb or
descent whenever he/she wishes and conducting the
climb or descent at any rate he/she wishes. He/she
may temporarily level off at any intermediate
altitude. However, once he/she has vacated an
altitude, he/she may not return to that altitude.
PIREP(See PILOT WEATHER REPORT.)
PITCH POINT- A fix/waypoint that serves as a
transition point from a departure procedure or the low
altitude ground-based navigation structure into the
high altitude waypoint system.
PLANS DISPLAY- A display available in URET
that provides detailed flight plan and predicted
conflict information in textual format for requested
Current Plans and all Trial Plans.
(See USER REQUEST EVALUATION TOOL.)
Pilot/Controller Glossary 2/14/08
PCG P-2
POFZ(See PRECISION OBSTACLE FREE ZONE.)
POINT OUT(See RADAR POINT OUT.)
POINT-TO-POINT (PTP)- A level of NRR service
for aircraft that is based on traditional waypoints in
their FMSs or RNAV equipage.
POLAR TRACK STRUCTURE- A system of
organized routes between Iceland and Alaska which
overlie Canadian MNPS Airspace.
POSITION AND HOLD- Used by ATC to inform a
pilot to taxi onto the departure runway in takeoff
position and hold. It is not authorization for takeoff.
It is used when takeoff clearance cannot immediately
be issued because of traffic or other reasons.
(See CLEARED FOR TAKEOFF.)
POSITION REPORT- A report over a known
location as transmitted by an aircraft to ATC.
(Refer to AIM.)
POSITION SYMBOL- A computer©\generated
indication shown on a radar display to indicate the
mode of tracking.
POSITIVE CONTROL- The separation of all air
traffic within designated airspace by air traffic
control.
PRACTICE INSTRUMENT APPROACH- An
instrument approach procedure conducted by a VFR
or an IFR aircraft for the purpose of pilot training or
proficiency demonstrations.
PRE-DEPARTURE CLEARANCE- An application
with the Terminal Data Link System (TDLS) that
provides clearance information to subscribers,
through a service provider, in text to the cockpit or
gate printer.
PREARRANGED COORDINATION- A standard©\
ized procedure which permits an air traffic controller
to enter the airspace assigned to another air traffic
controller without verbal coordination. The proce©\
dures are defined in a facility directive which ensures
standard separation between aircraft.
PREARRANGED COORDINATION PROCE©\
DURES- A facility's standardized procedure that
describes the process by which one controller shall
allow an aircraft to penetrate or transit another
controller's airspace in a manner that assures standard
separation without individual coordination for each
aircraft.
PRECIP ITATION- Any or all form s of water
particles (rain, sleet, hail, or snow) that fall from the
atmosphere and reach the surface.
PRECIPITATION RADAR WEATHER DE©\
SCRIPTIONS - Existing radar systems cannot detect
turbulence. However, there is a direct correlation
between the degree of turbulence and other weather
features associated with thunderstorms and the
weather radar precipitation intensity. Controllers will
issue (where capable) precipitation intensity as
observed by radar when using weather and radar
processor (WARP) or NAS ground based digital
radars with weather capabilities. When precipitation
intensity information is not available, the intensity
will be described as UNKNOWN. When intensity
levels can be determined, they shall be described as:
a. LIGHT (< 30 dBZ)
b. MODERATE (30 to 40 dBZ)
c. HEAVY (> 40 to 50 dBZ)
d. EXTREME (> 50 dBZ)
(Refer to AC 00-45, Aviation Weather Services.)
PRECISION APPROACH(See PRECISION APPROACH PROCEDURE.)
PRECISION APPROACH PROCEDURE- A stan©\
dard instrument approach procedure in which an
electronic glideslope/glidepath is provided; e.g., ILS,
MLS, and PAR.
(See INSTRUMENT LANDING SYSTEM.)
(See MICROWAVE LANDING SYSTEM.)
(See PRECISION APPROACH RADAR.)
PRECISION APPROACH RADAR- Radar equip©\
ment in some ATC facilities operated by the FAA
and/or the military services at joint©\use civil/military
locations and separate military installations to detect
and display azimuth, elevation, and range of aircraft
on the final approach course to a runway. This
equipment may be used to monitor certain nonradar
approaches, but is primarily used to conduct a
precision instrument approach (PAR) wherein the
controller issues guidance instructions to the pilot
based on the aircraft's position in relation to the final
approach course (azimuth), the glidepath (elevation),
Pilot/Controller Glossary 2/14/08
PCG P-3
and the distance (range) from the touchdown point on
the runway as displayed on the radar scope.
Note:The abbreviation ¡°PAR¡± is also used to
denote preferential arrival routes in ARTCC
computers.
(See GLIDEPATH.)
(See PAR.)
(See PREFERENTIAL ROUTES.)
(See ICAO term PRECISION APPROACH
RADAR.)
(Refer to AIM.)
PRECISION APPROACH RADAR [ICAO]- Pri©\
mary radar equipment used to determine the position
of an aircraft during final approach, in terms of lateral
and vertical deviations relative to a nominal approach
path, and in range relative to touchdown.
Note:Precision approach radars are designed to
enable pilots of aircraft to be given guidance by
radio communication during the final stages of the
approach to land.
PRECISION OBSTACLE FREE ZONE (POFZ)-
An 800 foot wide by 200 foot long area centered on
the runway centerline adjacent to the threshold
designed to protect aircraft flying precision
approaches from ground vehicles and other aircraft
when ceiling is less than 250 feet or visibility is less
than 3/4 statute mile (or runway visual range below
4,000 feet.)
PRECISION RUNWAY MONITOR (PRM)- Pro©\
vides air traffic controllers with high precision
secondary surveillance data for aircraft on final
approach to parallel runways that have extended
centerlines separated by less than 4,300 feet. High
resolution color monitoring displays (FMA) are
required to present surveillance track data to
controllers along with detailed maps depicting
approaches and no transgression zone.
PREFERENTIAL ROUTES- Preferential routes
(PDRs, PARs, and PDARs) are adapted in ARTCC
computers to accomplish inter/intrafacility controller
coordination and to assure that flight data is posted at
the proper control positions. Locations having a need
for these specific inbound and outbound routes
normally publish such routes in local facility
bulletins, and their use by pilots minimizes flight
plan route amendments. When the workload or traffic
situation permits, controllers normally provide radar
vectors or assign requested routes to minimize
circuitous routing. Preferential routes are usually
confined to one ARTCC's area and are referred to by
the following names or acronyms:
a. Preferential Departure Route (PDR). A specific
departure route from an airport or terminal area to an
en route point where there is no further need for flow
control. It may be included in an Instrument
Departure Procedure (DP) or a Preferred IFR Route.
b. Preferential Arrival Route (PAR). A specific
arrival route from an appropriate en route point to an
airport or terminal area. It may be included in a
Standard Terminal Arrival (STAR) or a Preferred IFR
Route. The abbreviation ¡°PAR¡± is used primarily
within the ARTCC and should not be confused with
the abbreviation for Precision Approach Radar.
c. Preferential Departure and Arrival Route
(PDAR). A route between two terminals which are
within or immediately adjacent to one ARTCC's area.
PDARs are not synonymous with Preferred IFR
Routes but may be listed as such as they do
accomplish essentially the same purpose.
(See PREFERRED IFR ROUTES.)
PREFERRED IFR ROUTES- Routes established
between busier airports to increase system efficiency
and capacity. They normally extend through one or
more ARTCC areas and are designed to achieve
balanced traffic flows among high density terminals.
IFR clearances are issued on the basis of these routes
except when severe weather avoidance procedures or
other factors dictate otherwise. Preferred IFR Routes
are listed in the Airport/Facility Directory. If a flight
is planned to or from an area having such routes but
the departure or arrival point is not listed in the
Airport/Facility Directory, pilots may use that part of
a Preferred IFR Route which is appropriate for the
departure or arrival point that is listed. Preferred IFR
Routes are correlated with DPs and STARs and may
be defined by airways, jet routes, direct routes
between NAVAIDs, Waypoints, NAVAID radials/
DME, or any combinations thereof.
(See CENTER'S AREA.)
(See INSTRUMENT DEPARTURE
PROCEDURE.)
(See PREFERENTIAL ROUTES.)
(See STANDARD TERMINAL ARRIVAL.)
(Refer to AIRPORT/FACILITY DIRECTORY.)
(Refer to NOTICES TO AIRMEN PUBLICATION.)
PRE©\FLIGHT PILOT BRIEFING(See PILOT BRIEFING.)
PREVAILING VISIBILITY(See VISIBILITY.)
Pilot/Controller Glossary 2/14/08
PCG P-4
PRIMARY RADAR TARGET- An analog or digital
target, exclusive of a secondary radar target,
presented on a radar display.
PRM(See ILS PRM APPROACH and PRECISION
RUNWAY MONITOR.)
PROCEDURE TURN- The maneuver prescribed
when it is necessary to reverse direction to establish
an aircraft on the intermediate approach segment or
final approach course. The outbound course,
direction of turn, distance within which the turn must
be completed, and minimum altitude are specified in
the procedure. However, unless otherwise restricted,
the point at which the turn may be commenced and
the type and rate of turn are left to the discretion of the
pilot.
(See ICAO term PROCEDURE TURN.)
PROCEDURE TURN [ICAO]- A maneuver in
which a turn is made away from a designated track
followed by a turn in the opposite direction to permit
the aircraft to intercept and proceed along the
reciprocal of the designated track.
Note 1:Procedure turns are designated ¡°left¡± or
¡°right¡± according to the direction of the initial turn.
Note 2:Procedure turns may be designated as
being made either in level flight or while
descending, according to the circumstances of
each individual approach procedure.
PROCEDURE TURN INBOUND- That point of a
procedure turn maneuver where course reversal has
been completed and an aircraft is established inbound
on the intermediate approach segment or final
approach course. A report of ¡°procedure turn
inbound¡± is normally used by ATC as a position
report for separation purposes.
(See FINAL APPROACH COURSE.)
(See PROCEDURE TURN.)
(See SEGMENTS OF AN INSTRUMENT
APPROACH PROCEDURE.)
PROFILE DESCENT- An uninterrupted descent
(except where level flight is required for speed
adjustment; e.g., 250 knots at 10,000 feet MSL) from
cruising altitude/level to interception of a glideslope
or to a minimum altitude specified for the initial or
intermediate approach segment of a nonprecision
instrument approach. The profile descent normally
term inates at the approach gate or where the
glideslope or other appropriate minimum altitude is
intercepted.
PROGRESS REPORT(See POSITION REPORT.)
PROGRESSIVE TAXI- Precise taxi instructions
given to a pilot unfamiliar with the airport or issued
in stages as the aircraft proceeds along the taxi route.
PROHIBITED AREA(See SPECIAL USE AIRSPACE.)
(See ICAO term PROHIBITED AREA.)
PROHIBITED AREA [ICAO]- An airspace of
defined dimensions, above the land areas or territorial
waters of a State, within which the flight of aircraft
is prohibited.
PROPOSED BOUNDARY CROSSING TIME-
Each center has a PBCT parameter for each internal
airport. Proposed internal flight plans are transmitted
to the adjacent center if the flight time along the
proposed route from the departure airport to the
center boundary is less than or equal to the value of
PBCT or if airport adaptation specifies transmission
regardless of PBCT.
PROPOSED DEPARTURE TIME- The time that the
aircraft expects to become airborne.
PROTECTED AIRSPACE- The airspace on either
side of an oceanic route/track that is equal to one©\half
the lateral separation minimum except where
reduction of protected airspace has been authorized.
PT(See PROCEDURE TURN.)
PTP(See POINT-TO-POINT.)
PTS(See POLAR TRACK STRUCTURE.)
PUBLISHED ROUTE- A route for which an IFR
altitude has been established and published; e.g.,
Federal Airways, Jet Routes, Area Navigation
Routes, Specified Direct Routes.
Pilot/Controller Glossary 2/14/08
PCG Q-1
Q
Q ROUTE- `Q' is the designator assigned to
published RNAV routes used by the United States.
QNE- The barometric pressure used for the standard
altimeter setting (29.92 inches Hg.).
QNH- The barometric pressure as reported by a
particular station.
QUADRANT- A quarter part of a circle, centered on
a NAVAID, oriented clockwise from magnetic north
as follows: NE quadrant 000©\089, SE quadrant
090©\179, SW quadrant 180©\269, NW quadrant
270©\359.
QUEUING(See STAGING/QUEUING.)
QUICK LOOK- A feature of the EAS and ARTS
which provides the controller the capability to
display full data blocks of tracked aircraft from other
control positions.
Pilot/Controller Glossary 2/14/08
PCG R-1
R
RAA(See REMOTE AIRPORT ADVISORY.)
RADAR- A device which, by measuring the time
interval between transmission and reception of radio
pulses and correlating the angular orientation of the
radiated antenna beam or beams in azimuth and/or
elevation, provides information on range, azimuth,
and/or elevation of objects in the path of the
transmitted pulses.
a. Primary Radar- A radar system in which a
minute portion of a radio pulse transmitted from a site
is reflected by an object and then received back at that
site for processing and display at an air traffic control
facility.
b. Secondary Radar/Radar Beacon (ATCRBS)- A
radar system in which the object to be detected is
fitted with cooperative equipment in the form of a
radio receiver/transmitter (transponder). Radar
pulses transmitted from the searching transmitter/re©\
ceiver (interrogator) site are received in the
cooperative equipment and used to trigger a
distinctive transmission from the transponder. This
reply transmission, rather than a reflected signal, is
then received back at the transmitter/receiver site for
processing and display at an air traffic control facility.
(See INTERROGATOR.)
(See TRANSPONDER.)
(See ICAO term RADAR.)
(Refer to AIM.)
RADAR [ICAO]- A radio detection device which
provides information on range, azimuth and/or
elevation of objects.
a. Primary Radar- Radar system which uses
reflected radio signals.
b. Secondary Radar- Radar system wherein a
radio signal transmitted from a radar station initiates
the transmission of a radio signal from another
station.
RADAR ADVISORY- The provision of advice and
information based on radar observations.
(See ADVISORY SERVICE.)
RADAR ALTIMETER(See RADIO ALTIMETER.)
RADAR APPROACH- An instrument approach
procedure which utilizes Precision Approach Radar
(PAR) or Airport Surveillance Radar (ASR).
(See AIRPORT SURVEILLANCE RADAR.)
(See INSTRUMENT APPROACH
PROCEDURE.)
(See PRECISION APPROACH RADAR.)
(See SURVEILLANCE APPROACH.)
(See ICAO term RADAR APPROACH.)
(Refer to AIM.)
RADAR APPROACH [ICAO]- An approach,
executed by an aircraft, under the direction of a radar
controller.
RADAR APPROACH CONTROL FACILITY- A
terminal ATC facility that uses radar and nonradar
capabilities to provide approach control services to
aircraft arriving, departing, or transiting airspace
controlled by the facility.
(See APPROACH CONTROL SERVICE.)
a. Provides radar ATC services to aircraft
operating in the vicinity of one or more civil and/or
military airports in a terminal area. The facility may
provide services of a ground controlled approach
(GCA); i.e., ASR and PAR approaches. A radar
approach control facility may be operated by FAA,
USAF, US Army, USN, USMC, or jointly by FAA
and a military service. Specific facility nomencla©\
tures are used for administrative purposes only and
are related to the physical location of the facility and
the operating service generally as follows:
1. Army Radar Approach Control (ARAC)
(Army).
2. Radar Air Traffic Control Facility (RATCF)
(Navy/FAA).
3. Radar Approach Control (RAPCON) (Air
Force/FAA).
4. Term inal Radar Approach Control
(TRACON) (FAA).
5. Air Traffic Control Tower (ATCT) (FAA).
(Only those towers delegated approach control
authority.)
RADAR ARRIVAL- An aircraft arriving at an
airport served by a radar facility and in radar contact
with the facility.
(See NONRADAR.)
Pilot/Controller Glossary 2/14/08
PCG R-2
RADAR BEACON(See RADAR.)
RADAR CLUTTER [ICAO]- The visual indication
on a radar display of unwanted signals.
RADAR CONTACTa. Used by ATC to inform an aircraft that it is
identified on the radar display and radar flight
following will be provided until radar identification
is terminated. Radar service may also be provided
within the limits of necessity and capability. When a
pilot is inform ed of ¡°radar contact,¡± he/she
automatically discontinues reporting over compulso©\
ry reporting points.
(See RADAR CONTACT LOST.)
(See RADAR FLIGHT FOLLOWING.)
(See RADAR SERVICE.)
(See RADAR SERVICE TERMINATED.)
(Refer to AIM.)
b. The term used to inform the controller that the
aircraft is identified and approval is granted for the
aircraft to enter the receiving controllers airspace.
(See ICAO term RADAR CONTACT.)
RADAR CONTACT [ICAO]- The situation which
exists when the radar blip or radar position symbol of
a particular aircraft is seen and identified on a radar
display.
RADAR CONTACT LOST- Used by ATC to inform
a pilot that radar data used to determine the aircraft's
position is no longer being received, or is no longer
reliable and radar service is no longer being provided.
The loss may be attributed to several factors
including the aircraft merging with weather or ground
clutter, the aircraft operating below radar line of sight
coverage, the aircraft entering an area of poor radar
return, failure of the aircraft transponder, or failure of
the ground radar equipment.
(See CLUTTER.)
(See RADAR CONTACT.)
RADAR ENVIRONMENT- An area in which radar
service may be provided.
(See ADDITIONAL SERVICES.)
(See RADAR CONTACT.)
(See RADAR SERVICE.)
(See TRAFFIC ADVISORIES.)
RADAR FLIGHT FOLLOWING- The observation
of the progress of radar identified aircraft, whose
primary navigation is being provided by the pilot,
wherein the controller retains and correlates the
aircraft identity with the appropriate target or target
symbol displayed on the radar scope.
(See RADAR CONTACT.)
(See RADAR SERVICE.)
(Refer to AIM.)
RADAR IDENTIFIC ATION- The process of
ascertaining that an observed radar target is the radar
return from a particular aircraft.
(See RADAR CONTACT.)
(See RADAR SERVICE.)
(See ICAO term RADAR IDENTIFICATION.)
RADAR IDENTIFICATION [ICAO]- The process
of correlating a particular radar blip or radar position
symbol with a specific aircraft.
RADAR IDENTIFIED AIRCRAFT- An aircraft, the
position of which has been correlated with an
observed target or symbol on the radar display.
(See RADAR CONTACT.)
(See RADAR CONTACT LOST.)
RADAR MONITORING(See RADAR SERVICE.)
RADAR NAVIGATIONAL GUIDANCE(See RADAR SERVICE.)
RADAR POINT OUT- An action taken by a
controller to transfer the radar identification of an
aircraft to another controller if the aircraft will or may
enter the airspace or protected airspace of another
controller and radio communications will not be
transferred.
RADAR REQUIRED- A term displayed on charts
and approach plates and included in FDC NOTAMs
to alert pilots that segments of either an instrument
approach procedure or a route are not navigable
because of either the absence or unusability of a
NAVAID. The pilot can expect to be provided radar
navigational guidance while transiting segments
labeled with this term.
(See RADAR ROUTE.)
(See RADAR SERVICE.)
RADAR ROUTE- A flight path or route over which
an aircraft is vectored. Navigational guidance and
altitude assignments are provided by ATC.
(See FLIGHT PATH.)
(See ROUTE.)
RADAR SEPARATION(See RADAR SERVICE.)
Pilot/Controller Glossary 2/14/08
PCG R-3
RADAR SERVICE- A term which encompasses one
or more of the following services based on the use of
radar which can be provided by a controller to a pilot
of a radar identified aircraft.
a. Radar Monitoring- The radar flight©\following
of aircraft, whose primary navigation is being
performed by the pilot, to observe and note deviations
from its authorized flight path, airway, or route.
When being applied specifically to radar monitoring
of instrument approaches; i.e., with precision
approach radar (PAR) or radar monitoring of
simultaneous ILS/MLS approaches, it includes
advice and instructions whenever an aircraft nears or
exceeds the prescribed PAR safety limit or
simultaneous ILS/MLS no transgression zone.
(See ADDITIONAL SERVICES.)
(See TRAFFIC ADVISORIES.)
b. Radar Navigational Guidance- Vectoring
aircraft to provide course guidance.
c. Radar Separation- Radar spacing of aircraft in
accordance with established minima.
(See ICAO term RADAR SERVICE.)
RADAR SERVICE [ICAO]- Term used to indicate
a service provided directly by means of radar.
a. Monitoring- The use of radar for the purpose of
providing aircraft with information and advice
relative to significant deviations from nominal flight
path.
b. Separation- The separation used when aircraft
position information is derived from radar sources.
RADAR SERVICE TERMINATED- Used by ATC
to inform a pilot that he/she will no longer be
provided any of the services that could be received
while in radar contact. Radar service is automatically
terminated, and the pilot is not advised in the
following cases:
a. An aircraft cancels its IFR flight plan, except
within Class B airspace, Class C airspace, a TRSA,
or where Basic Radar service is provided.
b. An aircraft conducting an instrument, visual, or
contact approach has landed or has been instructed to
change to advisory frequency.
c. An arriving VFR aircraft, receiving radar
service to a tower©\controlled airport within Class B
airspace, Class C airspace, a TRSA, or where
sequencing service is provided, has landed; or to all
other airports, is instructed to change to tower or
advisory frequency.
d. An aircraft completes a radar approach.
RADAR SURVEILLANCE- The radar observation
of a given geographical area for the purpose of
performing some radar function.
RADAR TRAFFIC ADVISORIES- Advisories
issued to alert pilots to known or observed radar
traffic which may affect the intended route of flight
of their aircraft.
(See TRAFFIC ADVISORIES.)
RADAR TRAFFIC INFORMATION SERVICE(See TRAFFIC ADVISORIES.)
RADAR VECTORING [ICAO]- Provision of
navigational guidance to aircraft in the form of
specific headings, based on the use of radar.
RADIAL- A magnetic bearing extending from a
VOR/VORTAC/TACAN navigation facility.
RADIOa. A device used for communication.
b. Used to refer to a flight service station; e.g.,
¡°Seattle Radio¡± is used to call Seattle FSS.
RADIO ALTIMETER- Aircraft equipment which
makes use of the reflection of radio waves from the
ground to determine the height of the aircraft above
the surface.
RADIO BEACON(See NONDIRECTIONAL BEACON.)
RADIO DETECTION AND RANGING(See RADAR.)
RADIO MAGNETIC INDICATOR- An aircraft
navigational instrument coupled with a gyro compass
or similar compass that indicates the direction of a
selected NAVAID and indicates bearing with respect
to the heading of the aircraft.
RAIS(See REMOTE AIRPORT INFORMATION
SERVICE.)
RAMP(See APRON.)
RANDOM ALTITUDE- An altitude inappropriate
for direction of flight and/or not in accordance with
FAAO JO 7110.65, Para 4-5-1, VERTIC AL
SEPARATION MINIMA.
Pilot/Controller Glossary 2/14/08
PCG R-4
RANDOM ROUTE- Any route not established or
charted/published or not otherwise available to all
users.
RC(See ROAD RECONNAISSANCE.)
RCAG(See REMOTE COMMUNICATIONS
AIR/GROUND FACILITY.)
RCC(See RESCUE COORDINATION CENTER.)
RCO(See REMOTE COMMUNICATIONS OUTLET.)
RCR(See RUNWAY CONDITION READING.)
READ BACK- Repeat my message back to me.
RECEIVER AUTONOMOUS INTEGRITY MON©\
ITORING (RAIM)- A technique whereby a civil
GNSS receiver/processor determines the integrity of
the GNSS navigation signals without reference to
sensors or non©\DoD integrity systems other than the
receiver itself. This determination is achieved by a
consistency check among redundant pseudorange
measurements.
RECEIVING CONTROLLER- A controller/facility
receiving control of an aircraft from another
controller/facility.
RECEIVING FACILITY(See RECEIVING CONTROLLER.)
RECONFORMANCE- The automated process of
bringing an aircraft's Current Plan Trajectory into
conformance with its track.
REDUCE SPEED TO (SPEED)-
(See SPEED ADJUSTMENT.)
REIL(See RUNWAY END IDENTIFIER LIGHTS.)
RELEASE TIME- A departure time restriction
issued to a pilot by ATC (either directly or through an
authorized relay) when necessary to separate a
departing aircraft from other traffic.
(See ICAO term RELEASE TIME.)
RELEASE TIME [ICAO]- Time prior to which an
aircraft should be given further clearance or prior to
which it should not proceed in case of radio failure.
REMOTE AIR PORT ADVIS ORY (RAA)- A
remote service which may be provided by facilities,
which are not located on the landing airport, but have
a discrete ground-to-air communication frequency
or tower frequency when the tower is closed,
automated weather reporting with voice available to
the pilot at the landing airport, and a continuous
ASOS/AWOS data display, other direct reading
instruments, or manual observation is available to the
AFSS specialist.
REMOTE AIRPORT INFORMATION SERVICE
(RAIS)- A temporary service provided by facilities,
which are not located on the landing airport, but have
communication capability and automated weather
reporting available to the pilot at the landing airport.
REMOTE COMMUNICATIONS AIR/GROUND
FACILITY- An unmanned VHF/UHF transmitter/
receiver facility which is used to expand ARTCC
air/ground communications coverage and to facilitate
direct contact between pilots and controllers. RCAG
facilities are sometimes not equipped with emergen©\
cy frequencies 121.5 MHz and 243.0 MHz.
(Refer to AIM.)
REMOTE COMMUNICATIONS OUTLET- An
unmanned communications facility remotely con©\
trolled by air traffic personnel. RCOs serve FSSs.
RTRs serve terminal ATC facilities. An RCO or RTR
may be UHF or VHF and will extend the
communication range of the air traffic facility. There
are several classes of RCOs and RTRs. The class is
determ ined by the number of transmitters or
receivers. Classes A through G are used primarily for
air/ground purposes. RCO and RTR class O
facilities are nonprotected outlets subject to
undetected and prolonged outages. RCO (O's) and
RTR (O's) were established for the express purpose
of providing ground©\to©\ground communications
between air traffic control specialists and pilots
located at a satellite airport for delivering en route
clearances, issuing departure authorizations, and
acknowledging instrument flight rules cancellations
or departure/landing times. As a secondary function,
they may be used for advisory purposes whenever the
aircraft is below the coverage of the primary
air/ground frequency.
REMOTE TRANSMITTER/RECEIVER(See REMOTE COMMUNICATIONS OUTLET.)
Pilot/Controller Glossary 2/14/08
PCG R-5
REPORT- Used to instruct pilots to advise ATC of
specified information; e.g., ¡°Report passing Hamil©\
ton VOR.¡±
REPORTING POINT- A geographical location in
relation to which the position of an aircraft is
reported.
(See COMPULSORY REPORTING POINTS.)
(See ICAO term REPORTING POINT.)
(Refer to AIM.)
REPORTING POINT [ICAO]- A specified geo©\
graphical location in relation to which the position of
an aircraft can be reported.
REQUEST FULL ROUTE CLEARANCE- Used
by pilots to request that the entire route of flight be
read verbatim in an ATC clearance. Such request
should be made to preclude receiving an ATC
clearance based on the original filed flight plan when
a filed IFR flight plan has been revised by the pilot,
company, or operations prior to departure.
REQUIRED NAVIGATION PERFORMANCE
(RNP)¨C A statement of the navigational performance
necessary for operation within a defined airspace.
The following terms are commonly associated with
RNP:
a. Required Navigation Performance Level or
Type (RNP©\X). A value, in nautical miles (NM), from
the intended horizontal position within which an
aircraft would be at least 95©\percent of the total flying
time.
b. Required Navigation Performance (RNP)
Airspace. A generic term designating airspace, route
(s), leg (s), operation (s), or procedure (s) where
minimum required navigational performance (RNP)
have been established.
c. Actual Navigation Performance (ANP). A
measure of the current estimated navigational
performance. Also referred to as Estimated Position
Error (EPE).
d. Estimated Position Error (EPE). A measure of
the current estimated navigational performance. Also
referred to as Actual Navigation Performance (ANP).
e. Lateral Navigation (LNAV). A function of area
navigation (RNAV) equipment which calculates,
displays, and provides lateral guidance to a profile or
path.
f. Vertical Navigation (VNAV). A function of area
navigation (RNAV) equipment which calculates,
displays, and provides vertical guidance to a profile
or path.
RESCUE COORDINATION CENTER- A search
and rescue (SAR) facility equipped and manned to
coordinate and control SAR operations in an area
designated by the SAR plan. The U.S. Coast Guard
and the U.S. Air Force have responsibility for the
operation of RCCs.
(See ICAO term RESCUE CO©\ORDINATION
CENTRE.)
RESCUE CO©\ORDINATION CENTRE [ICAO]- A
unit responsible for promoting efficient organization
of search and rescue service and for coordinating the
conduct of search and rescue operations within a
search and rescue region.
RESOLUTION ADVISORY-A display indication
given to the pilot by the traffic alert and collision
avoidance systems (TCAS II) recommending a
maneuver to increase vertical separation relative to an
intruding aircraft. Positive, negative, and vertical
speed limit (VSL) advisories constitute the resolution
advisories. A resolution advisory is also classified as
corrective or preventive
RESTRICTED AREA(See SPECIAL USE AIRSPACE.)
(See ICAO term RESTRICTED AREA.)
RESTRICTED AREA [ICAO]- An airspace of
defined dimensions, above the land areas or territorial
waters of a State, within which the flight of aircraft
is restricted in accordance with certain specified
conditions.
RESUME NORMAL SPEED- Used by ATC to
advise a pilot that previously issued speed control
restrictions are deleted. An instruction to ¡°resume
normal speed¡± does not delete speed restrictions that
are applicable to published procedures of upcoming
segments of flight, unless specifically stated by ATC.
This does not relieve the pilot of those speed
restrictions which are applicable to 14 CFR
Section 91.117.
RESUME OWN NAVIGATION- Used by ATC to
advise a pilot to resume his/her own navigational
responsibility. It is issued after completion of a radar
Pilot/Controller Glossary 2/14/08
PCG R-6
vector or when radar contact is lost while the aircraft
is being radar vectored.
(See RADAR CONTACT LOST.)
(See RADAR SERVICE TERMINATED.)
RMI(See RADIO MAGNETIC INDICATOR.)
RNAV(See AREA NAVIGATION.)
(See ICAO Term AREA NAVIGATION.)
RNAV APPROACH- An instrument approach
procedure which relies on aircraft area navigation
equipment for navigational guidance.
(See AREA NAVIGATION.)
(See INSTRUMENT APPROACH
PROCEDURE.)
ROAD RECONNAISSANCE- Military activity
requiring navigation along roads, railroads, and
rivers. Reconnaissance route/route segments are
seldom along a straight line and normally require a
lateral route width of 10 NM to 30 NM and an altitude
range of 500 feet to 10,000 feet AGL.
ROGER- I have received all of your last
transmission. It should not be used to answer a
question requiring a yes or a no answer.
(See AFFIRMATIVE.)
(See NEGATIVE.)
ROLLOUT RVR(See VISIBILITY.)
ROUTE- A defined path, consisting of one or more
courses in a horizontal plane, which aircraft traverse
over the surface of the earth.
(See AIRWAY.)
(See JET ROUTE.)
(See PUBLISHED ROUTE.)
(See UNPUBLISHED ROUTE.)
ROUTE ACTION NOTIFICATION- URET notifi©\
cation that a PAR/PDR/PDAR has been applied to the
flight plan.
(See ATC PREFERRED ROUTE
NOTIFICATION.)
(See USER REQUEST EVALUATION TOOL.)
ROUTE SEGMENT- As used in Air Traffic Control,
a part of a route that can be defined by two
navigational fixes, two NAVAIDs, or a fix and a
NAVAID.
(See FIX.)
(See ROUTE.)
(See ICAO term ROUTE SEGMENT.)
ROUTE SEGMENT [ICAO]- A portion of a route to
be flown, as defined by two consecutive significant
points specified in a flight plan.
RSA(See RUNWAY SAFETY AREA.)
RTR(See REMOTE TRANSMITTER/RECEIVER.)
RUNWAY- A defined rectangular area on a land
airport prepared for the landing and takeoff run of
aircraft along its length. Runways are normally
numbered in relation to their magnetic direction
rounded off to the nearest 10 degrees; e.g., Runway
1, Runway 25.
(See PARALLEL RUNWAYS.)
(See ICAO term RUNWAY.)
RUNWAY [ICAO]- A defined rectangular area on a
land aerodrome prepared for the landing and take©\off
of aircraft.
RUNWAY CENTERLINE LIGHTING(See AIRPORT LIGHTING.)
RUNWAY CONDITION READING- Numerical
decelerometer readings relayed by air traffic
controllers at USAF and certain civil bases for use by
the pilot in determining runway braking action.
These readings are routinely relayed only to USAF
and Air National Guard Aircraft.
(See BRAKING ACTION.)
RUNWAY END IDENTIFIER LIGHTS(See AIRPORT LIGHTING.)
RUNWAY GRADIENT- The average slope, mea©\
sured in percent, between two ends or points on a
runway. Runway gradient is depicted on Government
aerodrome sketches when total runway gradient
exceeds 0.3%.
RUNWAY HEADING- The magnetic direction that
corresponds with the runway centerline extended, not
the painted runway number. When cleared to ¡°fly or
maintain runway heading,¡± pilots are expected to fly
or maintain the heading that corresponds with the
extended centerline of the departure runway. Drift
correction shall not be applied; e.g., Runway 4, actual
Pilot/Controller Glossary 2/14/08
PCG R-7
magnetic heading of the runway centerline 044, fly
044.
RUNWAY IN USE/ACTIVE RUNWAY/DUTY
RUNWAY- Any runway or runways currently being
used for takeoff or landing. When multiple runways
are used, they are all considered active runways. In
the metering sense, a selectable adapted item which
specifies the landing runway configuration or
direction of traffic flow. The adapted optimum flight
plan from each transition fix to the vertex is
determined by the runway configuration for arrival
metering processing purposes.
RUNWAY LIGHTS(See AIRPORT LIGHTING.)
RUNWAY MARKINGS(See AIRPORT MARKING AIDS.)
RUNWAY OVERRUN- In military aviation exclu©\
sively, a stabilized or paved area beyond the end of a
runway, of the same width as the runway plus
shoulders, centered on the extended runway
centerline.
RUNWAY PROFILE DESCENT- An instrument
flight rules (IFR) air traffic control arrival procedure
to a runway published for pilot use in graphic and/or
textual form and may be associated with a STAR.
Runway Profile Descents provide routing and may
depict crossing altitudes, speed restrictions, and
headings to be flown from the en route structure to the
point where the pilot will receive clearance for and
execute an instrument approach procedure. A
Runway Profile Descent may apply to more than one
runway if so stated on the chart.
(Refer to AIM.)
RUNWAY SAFETY AREA- A defined surface
surrounding the runway prepared, or suitable, for
reducing the risk of damage to airplanes in the event
of an undershoot, overshoot, or excursion from the
runway. The dimensions of the RSA vary and can be
determined by using the criteria contained within
AC 150/5300©\13, Airport Design, Chapter 3.
Figure3-1 in AC 150/5300©\13 depicts the RSA. The
design standards dictate that the RSA shall be:
a. Cleared, graded, and have no potentially
hazardous ruts, humps, depressions, or other surface
variations;
b. Drained by grading or storm sewers to prevent
water accumulation;
c. Capable, under dry conditions, of supporting
snow rem oval equipment, aircraft rescue and
firefighting equipment, and the occasional passage of
aircraft without causing structural damage to the
aircraft; and,
d. Free of objects, except for objects that need to
be located in the runway safety area because of their
function. These objects shall be constructed on low
impact resistant supports (frangible mounted struc©\
tures) to the lowest practical height with the frangible
point no higher than 3 inches above grade.
(Refer to AC 150/5300©\13, Airport Design,
Chapter 3.)
RUNWAY TRANSITIONa. Conventional STARs/SIDs. The portion of a
STAR/SID that serves a particular runway or
runways at an airport.
b. RNAV STARs/SIDs. Defines a path(s) from
the common route to the final point(s) on a STAR. For
a SID, the common route that serves a particular
runway or runways at an airport.
RUNWAY USE PROGRAM- A noise abatement
runway selection plan designed to enhance noise
abatement efforts with regard to airport communities
for arriving and departing aircraft. These plans are
developed into runway use programs and apply to all
turbojet aircraft 12,500 pounds or heavier; turbojet
aircraft less than 12,500 pounds are included only if
the airport proprietor determines that the aircraft
creates a noise problem. Runway use programs are
coordinated with FAA offices, and safety criteria
used in these programs are developed by the Office of
Flight Operations. Runway use program s are
administered by the Air Traffic Service as ¡°Formal¡±
or ¡°Informal¡± programs.
a. Formal Runway Use Program- An approved
noise abatement program which is defined and
acknowledged in a Letter of Understanding between
Flight Operations, Air Traffic Service, the airport
proprietor, and the users. Once established, participa©\
tion in the program is mandatory for aircraft operators
and pilots as provided for in 14 CFR Section 91.129.
b. Informal Runway Use Program- An approved
noise abatement program which does not require a
Letter of Understanding, and participation in the
program is voluntary for aircraft operators/pilots.
Pilot/Controller Glossary 2/14/08
PCG R-8
RUNWAY VISIBILITY VALUE(See VISIBILITY.)
RUNWAY VISUAL RANGE(See VISIBILITY.)
Pilot/Controller Glossary 2/14/08
PCG S-1
S
SAA(See SPECIAL ACTIVITY AIRSPACE.)
SAFETY ALERT- A safety alert issued by ATC to
aircraft under their control if ATC is aware the aircraft
is at an altitude which, in the controller's judgment,
places the aircraft in unsafe proximity to terrain,
obstructions, or other aircraft. The controller may
discontinue the issuance of further alerts if the pilot
advises he/she is taking action to correct the situation
or has the other aircraft in sight.
a. Terrain/Obstruction Alert- A safety alert issued
by ATC to aircraft under their control if ATC is aware
the aircraft is at an altitude which, in the controller's
judgment, places the aircraft in unsafe proximity to
terrain/obstructions; e.g., ¡°Low Altitude Alert, check
your altitude immediately.¡±
b. Aircraft Conflict Alert- A safety alert issued by
ATC to aircraft under their control if ATC is aware of
an aircraft that is not under their control at an altitude
which, in the controller's judgment, places both
aircraft in unsafe proximity to each other. With the
alert, ATC will offer the pilot an alternate course of
action when feasible; e.g., ¡°Traffic Alert, advise you
turn right heading zero niner zero or climb to eight
thousand immediately.¡±
Note:The issuance of a safety alert is contingent
upon the capability of the controller to have an
awareness of an unsafe condition. The course of
action provided will be predicated on other traffic
under ATC control. Once the alert is issued, it is
solely the pilot's prerogative to determine what
course of action, if any, he/she will take.
SAFETY LOGIC SYSTEM- A software enhance©\
ment to ASDE-3, ASDE-X, and ASDE-3X, that
predicts the path of aircraft landing and/or departing,
and/or vehicular movements on runways. Visual and
aural alarms are activated when the safety logic
projects a potential collision. The Airport Movement
Area Safety System (AMASS) is a safety logic
system enhancement to the ASDE-3. The Safety
Logic System for ASDE-X and ASDE-3X is an
integral part of the software program.
SAFETY LOGIC SYSTEM ALERTSa. ALERT- An actual situation involving two real
safety logic tracks (aircraft/aircraft, aircraft/vehicle,
or aircraft/other tangible object) that safety logic has
predicted will result in an imminent collision, based
upon the current set of Safety Logic parameters.
b. FALSE ALERT1. Alerts generated by one or more false
surface-radar targets that the system has interpreted
as real tracks and placed into safety logic.
2. Alerts in which the safety logic software did
not perform correctly, based upon the design
specifications and the current set of Safety Logic
parameters.
c. NUISANCE ALERT- An alert in which one or
more of the following is true:
1. The alert is generated by a known situation
that is not considered an unsafe operation, such as
LAHSO or other approved operations.
2. The alert is generated by inaccurate secon©\
dary radar data received by the Safety Logic System.
3. The alert is generated by surface radar targets
caused by moderate or greater precipitation.
4. One or more of the aircraft involved in the
alert is not intending to use a runway (i.e., helicopter,
pipeline patrol, non-Mode C overflight, etc.).
d. VALID NON-ALERT- A situation in which
the safety logic software correctly determines that an
alert is not required, based upon the design
specifications and the current set of Safety Logic
parameters.
e. INVALID NON-ALERT- A situation in which
the safety logic software did not issue an alert when
an alert was required, based upon the design
specifications.
SAIL BACK- A maneuver during high wind
conditions (usually with power off) where float plane
movement is controlled by water rudders/opening
and closing cabin doors.
SAME DIRECTION AIRCRAFT- Aircraft are
operating in the same direction when:
a. They are following the same track in the same
direction; or
b. Their tracks are parallel and the aircraft are
flying in the same direction; or
c. Their tracks intersect at an angle of less than 45
degrees.
Pilot/Controller Glossary 2/14/08
PCG S-2
SAR(See SEARCH AND RESCUE.)
SAY AGAIN- Used to request a repeat of the last
transmission. Usually specifies transmission or
portion thereof not understood or received; e.g., ¡°Say
again all after ABRAM VOR.¡±
SAY ALTITUDE- Used by ATC to ascertain an
aircraft's specific altitude/flight level. When the
aircraft is climbing or descending, the pilot should
state the indicated altitude rounded to the nearest 100
feet.
SAY HEADING- Used by ATC to request an aircraft
heading. The pilot should state the actual heading of
the aircraft.
SCHEDULED TIME OF ARRIVAL (STA)- A STA
is the desired time that an aircraft should cross a
certain point (landing or metering fix). It takes other
traffic and airspace configuration into account. A
STA time shows the results of the TMA scheduler
that has calculated an arrival time according to
parameters such as optimized spacing, aircraft
performance, and weather.
SDF(See SIMPLIFIED DIRECTIONAL FACILITY.)
SEA LANE- A designated portion of water outlined
by visual surface markers for and intended to be used
by aircraft designed to operate on water.
SEARCH AND RESCUE- A service which seeks
missing aircraft and assists those found to be in need
of assistance. It is a cooperative effort using the
facilities and services of available Federal, state and
local agencies. The U.S. Coast Guard is responsible
for coordination of search and rescue for the Maritime
Region, and the U.S. Air Force is responsible for
search and rescue for the Inland Region. Information
pertinent to search and rescue should be passed
through any air traffic facility or be transmitted
directly to the Rescue Coordination Center by
telephone.
(See FLIGHT SERVICE STATION.)
(See RESCUE COORDINATION CENTER.)
(Refer to AIM.)
SEARCH AND RESCUE FACILITY- A facility
responsible for maintaining and operating a search
and rescue (SAR) service to render aid to persons and
property in distress. It is any SAR unit, station, NET,
or other operational activity which can be usefully
employed during an SAR Mission; e.g., a Civil Air
Patrol Wing, or a Coast Guard Station.
(See SEARCH AND RESCUE.)
SECONDARY RADAR TARGET- A target derived
from a transponder return presented on a radar
display.
SECTIONAL AERONAUTICAL CHARTS(See AERONAUTICAL CHART.)
SECTOR LIST DROP INTERVAL- A parameter
number of minutes after the meter fix time when
arrival aircraft will be deleted from the arrival sector
list.
SEE AND AVOID- When weather conditions
permit, pilots operating IFR or VFR are required to
observe and maneuver to avoid other aircraft.
Right©\of©\way rules are contained in 14 CFR Part 91.
SEGMENTED CIR CLE- A system of visual
indicators designed to provide traffic pattern
information at airports without operating control
towers.
(Refer to AIM.)
SEGMENTS OF AN INSTRUMENT APPROACH
PROCEDURE- An instrument approach procedure
may have as many as four separate segm ents
depending on how the approach procedure is
structured.
a. Initial Approach- The segment between the
initial approach fix and the intermediate fix or the
point where the aircraft is established on the
intermediate course or final approach course.
(See ICAO term INITIAL APPROACH
SEGMENT.)
b. Intermediate Approach- The segment between
the intermediate fix or point and the final approach
fix.
(See ICAO term INTERMEDIATE APPROACH
SEGMENT.)
c. Final Approach- The segment between the final
approach fix or point and the runway, airport, or
missed approach point.
(See ICAO term FINAL APPROACH SEGMENT.)
d. Missed Approach- The segment between the
missed approach point or the point of arrival at
Pilot/Controller Glossary 2/14/08
PCG S-3
decision height and the missed approach fix at the
prescribed altitude.
(Refer to 14 CFR Part 97.)
(See ICAO term MISSED APPROACH
PROCEDURE.)
SEPARATION- In air traffic control, the spacing of
aircraft to achieve their safe and orderly movement in
flight and while landing and taking off.
(See SEPARATION MINIMA.)
(See ICAO term SEPARATION.)
SEPARATION [ICAO]- Spacing between aircraft,
levels or tracks.
SEPARATION MINIMA- The minimum longitudi©\
nal, lateral, or vertical distances by which aircraft are
spaced through the application of air traffic control
procedures.
(See SEPARATION.)
SERVICE- A generic term that designates functions
or assistance available from or rendered by air traffic
control. For example, Class C service would denote
the ATC services provided within a Class C airspace
area.
SEVERE WEATHER AVOIDANCE PLAN- An
approved plan to minimize the affect of severe
weather on traffic flows in impacted terminal and/or
ARTCC areas. SWAP is normally implemented to
provide the least disruption to the ATC system when
flight through portions of airspace is difficult or
impossible due to severe weather.
SEVERE WEATHER FORECAST ALERTS-
Preliminary messages issued in order to alert users
that a Severe Weather Watch Bulletin (WW) is being
issued. These messages define areas of possible
severe thunderstorms or tornado activity. The
messages are unscheduled and issued as required by
the Storm Prediction Center (SPC) at Norman,
Oklahoma.
(See AIRMET.)
(See CONVECTIVE SIGMET.)
(See CWA.)
(See SIGMET.)
SFA(See SINGLE FREQUENCY APPROACH.)
SFO(See SIMULATED FLAMEOUT.)
SHF(See SUPER HIGH FREQUENCY.)
SHORT RANGE CLEARANCE- A clearance
issued to a departing IFR flight which authorizes IFR
flight to a specific fix short of the destination while
air traffic control facilities are coordinating and
obtaining the complete clearance.
SHORT TAKEOFF AND LANDING AIRCRAFT-
An aircraft which, at some weight within its approved
operating weight, is capable of operating from a
STOL runway in compliance with the applicable
STOL characteristics, airworthiness, operations,
noise, and pollution standards.
(See VERTICAL TAKEOFF AND LANDING
AIRCRAFT.)
SIAP(See STANDARD INSTRUMENT APPROACH
PROCEDURE.)
SID(See STANDARD INSTRUMENT DEPARTURE.)
SIDESTEP MANEUVER- A visual maneuver
accomplished by a pilot at the completion of an
instrument approach to permit a straight©\in landing
on a parallel runway not more than 1,200 feet to either
side of the runway to which the instrument approach
was conducted.
(Refer to AIM.)
SIGMET- A weather advisory issued concerning
weather significant to the safety of all aircraft.
SIGMET advisories cover severe and extreme
turbulence, severe icing, and widespread dust or
sandstorms that reduce visibility to less than 3 miles.
(See AIRMET.)
(See AWW.)
(See CONVECTIVE SIGMET.)
(See CWA.)
(See ICAO term SIGMET INFORMATION.)
(Refer to AIM.)
SIGMET INFORMATION [ICAO]- Information
issued by a meteorological watch office concerning
the occurrence or expected occurrence of specified
en©\route weather phenomena which may affect the
safety of aircraft operations.
SIGNIFICANT METEOROLOGICAL INFOR©\
MATION(See SIGMET.)
SIGNIFICANT POINT- A point, whether a named
intersection, a NAVAID, a fix derived from a
Pilot/Controller Glossary 2/14/08
PCG S-4
NAVAID(s), or geographical coordinate expressed in
degrees of latitude and longitude, which is
established for the purpose of providing separation,
as a reporting point, or to delineate a route of flight.
SIMPLIFIED DIRECTIONAL FACILITY- A
NAVAID used for nonprecision instrument ap©\
proaches. The final approach course is similar to that
of an ILS localizer except that the SDF course may be
offset from the runway, generally not more than 3
degrees, and the course may be wider than the
localizer, resulting in a lower degree of accuracy.
(Refer to AIM.)
SIMULATED FLAMEOUT- A practice approach
by a jet aircraft (normally military) at idle thrust to a
runway. The approach may start at a runway (high
key) and may continue on a relatively high and wide
downwind leg with a continuous turn to final. It
terminates in landing or low approach. The purpose
of this approach is to simulate a flameout.
(See FLAMEOUT.)
SIMULTANEOUS ILS APPROACHES- An ap©\
proach system permitting simultaneous ILS/MLS
approaches to airports having parallel runways
separated by at least 4,300 feet between centerlines.
Integral parts of a total system are ILS/MLS, radar,
communications, ATC procedures, and appropriate
airborne equipment.
(See PARALLEL RUNWAYS.)
(Refer to AIM.)
SIMULTANEOUS MLS APPROACHES(See SIMULTANEOUS ILS APPROACHES.)
SINGLE DIRECTION ROUTES- Preferred IFR
Routes which are sometimes depicted on high
altitude en route charts and which are normally flown
in one direction only.
(See PREFERRED IFR ROUTES.)
(Refer to AIRPORT/FACILITY DIRECTORY.)
SINGLE FREQUENCY APPROACH- A service
provided under a letter of agreement to military
single©\piloted turbojet aircraft which permits use of
a single UHF frequency during approach for landing.
Pilots will not normally be required to change
frequency from the beginning of the approach to
touchdown except that pilots conducting an en route
descent are required to change frequency when
control is transferred from the air route traffic control
center to the terminal facility. The abbreviation
¡°SFA¡± in the DOD FLIP IFR Supplement under
¡°Communications¡± indicates this service is available
at an aerodrome.
SINGLE©\PILOTED AIRCRAFT- A military turbo©\
jet aircraft possessing one set of flight controls,
tandem cockpits, or two sets of flight controls but
operated by one pilot is considered single©\piloted by
ATC when determining the appropriate air traffic
service to be applied.
(See SINGLE FREQUENCY APPROACH.)
SKYSPOTTER- A pilot who has received special©\
ized training in observing and reporting inflight
weather phenomena.
SLASH- A radar beacon reply displayed as an
elongated target.
SLDI(See SECTOR LIST DROP INTERVAL.)
SLOT TIME(See METER FIX TIME/SLOT TIME.)
SLOW TAXI- To taxi a float plane at low power or
low RPM.
SN(See SYSTEM STRATEGIC NAVIGATION.)
SPEAK SLOWER- Used in verbal communications
as a request to reduce speech rate.
SPECIAL ACTIVITY AIRSPACE (SAA)- Any
airspace with defined dimensions within the National
Airspace System wherein limitations may be
imposed upon aircraft operations. This airspace may
be restricted areas, prohibited areas, military
operations areas, air ATC assigned airspace, and any
other designated airspace areas. The dimensions of
this airspace are programmed into URET and can be
designated as either active or inactive by screen entry.
Aircraft trajectories are constantly tested against the
dimensions of active areas and alerts issued to the
applicable sectors when violations are predicted.
(See USER REQUEST EVALUATION TOOL.)
SPECIAL EMERGENCY- A condition of air piracy
or other hostile act by a person(s) aboard an aircraft
which threatens the safety of the aircraft or its
passengers.
SPECIAL INSTRUMENT APPROACH PROCE©\
DURE(See INSTRUMENT APPROACH PROCEDURE.)
Pilot/Controller Glossary 2/14/08
PCG S-5
SPECIAL USE AIRSPACE- Airspace of defined
dimensions identified by an area on the surface of the
earth wherein activities must be confined because of
their nature and/or wherein limitations may be
imposed upon aircraft operations that are not a part of
those activities. Types of special use airspace are:
a. Alert Area- Airspace which may contain a high
volume of pilot training activities or an unusual type
of aerial activity, neither of which is hazardous to
aircraft. Alert Areas are depicted on aeronautical
charts for the information of nonparticipating pilots.
All activities within an Alert Area are conducted in
accordance with Federal Aviation Regulations, and
pilots of participating aircraft as well as pilots
transiting the area are equally responsible for
collision avoidance.
b. Controlled Firing Area- Airspace wherein
activities are conducted under conditions so
controlled as to eliminate hazards to nonparticipating
aircraft and to ensure the safety of persons and
property on the ground.
c. Military Operations Area (MOA)- A MOA is
airspace established outside of Class A airspace area
to separate or segregate certain nonhazardous
military activities from IFR traffic and to identify for
VFR traffic where these activities are conducted.
(Refer to AIM.)
d. Prohibited Area- Airspace designated under
14 CFR Part 73 within which no person may operate
an aircraft without the permission of the using
agency.
(Refer to AIM.)
(Refer to En Route Charts.)
e. Restricted Area- Airspace designated under
14 CFR Part 73, within which the flight of aircraft,
while not wholly prohibited, is subject to restriction.
Most restricted areas are designated joint use and
IFR/VFR operations in the area may be authorized by
the controlling ATC facility when it is not being
utilized by the using agency. Restricted areas are
depicted on en route charts. Where joint use is
authorized, the name of the ATC controlling facility
is also shown.
(Refer to 14 CFR Part 73.)
(Refer to AIM.)
f. Warning Area- A warning area is airspace of
defined dimensions extending from 3 nautical miles
outward from the coast of the United States, that
contains activity that may be hazardous to
nonparticipating aircraft. The purpose of such
warning area is to warn nonparticipating pilots of the
potential danger. A warning area may be located over
domestic or international waters or both.
SPECIAL VFR CONDITIONS- Meteorological
conditions that are less than those required for basic
VFR flight in Class B, C, D, or E surface areas and
in which some aircraft are permitted flight under
visual flight rules.
(See SPECIAL VFR OPERATIONS.)
(Refer to 14 CFR Part 91.)
SPECIAL VFR FLIGHT [ICAO]- A VFR flight
cleared by air traffic control to operate within Class
B, C, D, and E surface areas in metrological
conditions below VMC.
SPECIAL VFR OPERATIONS- Aircraft operating
in accordance with clearances within Class B, C, D,
and E surface areas in weather conditions less than the
basic VFR weather minima. Such operations must be
requested by the pilot and approved by ATC.
(See SPECIAL VFR CONDITIONS.)
(See ICAO term SPECIAL VFR FLIGHT.)
SPEED(See AIRSPEED.)
(See GROUND SPEED.)
SPEED ADJUSTMENT- An ATC procedure used to
request pilots to adjust aircraft speed to a specific
value for the purpose of providing desired spacing.
Pilots are expected to maintain a speed of plus or
minus 10 knots or 0.02 Mach number of the specified
speed. Examples of speed adjustments are:
a. ¡°Increase/reduce speed to Mach point (num©\
ber.)¡±
b. ¡°Increase/reduce speed to (speed in knots)¡± or
¡°Increase/reduce speed (number of knots) knots.¡±
SPEED BRAKES- Moveable aerodynamic devices
on aircraft that reduce airspeed during descent and
landing.
SPEED SEGMENTS- Portions of the arrival route
between the transition point and the vertex along the
optimum flight path for which speeds and altitudes
are specified. There is one set of arrival speed
segments adapted from each transition point to each
vertex. Each set may contain up to six segments.
SQUAWK (Mode, Code, Function)- Activate
specific modes/codes/functions on the aircraft
transponder; e.g., ¡°Squawk three/alpha, two one zero
five, low.¡±
(See TRANSPONDER.)
Pilot/Controller Glossary 2/14/08
PCG S-6
STA(See SCHEDULED TIME OF ARRIVAL.)
STAGING/QUEUING- The placement, integration,
and segregation of departure aircraft in designated
movement areas of an airport by departure fix, EDCT,
and/or restriction.
STAND BY- Means the controller or pilot must
pause for a few seconds, usually to attend to other
duties of a higher priority. Also means to wait as in
¡°stand by for clearance. ¡± The caller should
reestablish contact if a delay is lengthy. ¡°Stand by¡± is
not an approval or denial.
STANDARD INSTRUMENT APPROACH PRO©\
CEDURE (SIAP)-
(See INSTRUMENT APPROACH PROCEDURE.)
STANDARD INSTRUMENT DEPARTURE (SID)-
A preplanned instrument flight rule (IFR) air traffic
control (ATC) departure procedure printed for
pilot/controller use in graphic form to provide
obstacle clearance and a transition from the terminal
area to the appropriate en route structure. SIDs are
primarily designed for system enhancement to
expedite traffic flow and to reduce pilot/controller
workload. ATC clearance must always be received
prior to flying a SID.
(See IFR TAKEOFF MINIMUMS AND
DEPARTURE PROCEDURES.)
(See OBSTACLE DEPARTURE PROCEDURE.)
(Refer to AIM.)
STANDARD RATE TURN- A turn of three degrees
per second.
STANDARD TERMINAL ARRIVAL- A pre©\
planned instrument flight rule (IFR) air traffic control
arrival procedure published for pilot use in graphic
and/or textual form. STARs provide transition from
the en route structure to an outer fix or an instrument
approach fix/arrival waypoint in the terminal area.
STANDARD TERMINAL ARRIVAL CHARTS(See AERONAUTICAL CHART.)
STANDARD TERMINAL AUTOMATION RE©\
PLACEMENT SYSTEM (STARS)-
(See DTAS.)
STAR(See STANDARD TERMINAL ARRIVAL.)
STATE AIRCRAFT- Aircraft used in military,
customs and police service, in the exclusive service
of any government, or of any political subdivision,
thereof including the government of any state,
territory, or possession of the United States or the
District of Columbia, but not including any
government©\owned aircraft engaged in carrying
persons or property for commercial purposes.
STATIC RESTRICTIONS- Those restrictions that
are usually not subject to change, fixed, in place,
and/or published.
STATIONARY RESERVATIONS- Altitude reserva©\
tions which encompass activities in a fixed area.
Stationary reservations may include activities, such
as special tests of weapons systems or equipment,
certain U.S. Navy carrier, fleet, and anti©\submarine
operations, rocket, missile and drone operations, and
certain aerial refueling or similar operations.
STEP TAXI- To taxi a float plane at full power or
high RPM.
STEP TURN- A maneuver used to put a float plane
in a planing configuration prior to entering an active
sea lane for takeoff. The STEP TURN maneuver
should only be used upon pilot request.
STEPDOWN FIX- A fix permitting additional
descent within a segment of an instrument approach
procedure by identifying a point at which a
controlling obstacle has been safely overflown.
STEREO ROUTE- A routinely used route of flight
established by users and ARTCCs identified by a
coded name; e.g., ALPHA 2. These routes minimize
flight plan handling and communications.
STOL AIRCRAFT(See SHORT TAKEOFF AND LANDING
AIRCRAFT.)
STOP ALTITUDE SQUAWK- Used by ATC to
inform an aircraft to turn©\off the automatic altitude
reporting feature of its transponder. It is issued when
the verbally reported altitude varies 300 feet or more
from the automatic altitude report.
(See ALTITUDE READOUT.)
(See TRANSPONDER.)
STOP AND GO- A procedure wherein an aircraft
will land, make a complete stop on the runway, and
then commence a takeoff from that point.
(See LOW APPROACH.)
(See OPTION APPROACH.)
Pilot/Controller Glossary 2/14/08
PCG S-7
STOP BURST(See STOP STREAM.)
STOP BUZZER(See STOP STREAM.)
STOP SQUAWK (Mode or Code)- Used by ATC to
tell the pilot to turn specified functions of the aircraft
transponder off.
(See STOP ALTITUDE SQUAWK.)
(See TRANSPONDER.)
STOP STREAM- Used by ATC to request a pilot to
suspend electronic attack activity.
(See JAMMING.)
STOPOVER FLIGHT PLAN- A flight plan format
which permits in a single submission the filing of a
sequence of flight plans through interim full©\stop
destinations to a final destination.
STOPWAY- An area beyond the takeoff runway no
less wide than the runway and centered upon the
extended centerline of the runway, able to support the
airplane during an aborted takeoff, without causing
structural damage to the airplane, and designated by
the airport authorities for use in decelerating the
airplane during an aborted takeoff.
STRAIGHT©\IN APPROACH IFR- An instrument
approach wherein final approach is begun without
first having executed a procedure turn, not
necessarily completed with a straight©\in landing or
made to straight©\in landing minimums.
(See LANDING MINIMUMS.)
(See STRAIGHT©\IN APPROACH VFR.)
(See STRAIGHT©\IN LANDING.)
STRAIGHT©\IN APPROACH VFR- Entry into the
traffic pattern by interception of the extended runway
centerline (final approach course) without executing
any other portion of the traffic pattern.
(See TRAFFIC PATTERN.)
STRAIGHT©\IN LANDING- A landing made on a
runway aligned within 30 of the final approach
course following completion of an instrument
approach.
(See STRAIGHT©\IN APPROACH IFR.)
STRAIGHT©\IN LANDING MINIMUMS(See LANDING MINIMUMS.)
STRAIGHT©\IN MINIMUMS(See STRAIGHT©\IN LANDING MINIMUMS.)
STRATEGIC PLANNING- Planning whereby
solutions are sought to resolve potential conflicts.
SUBSTITUTE ROUTE- A route assigned to pilots
when any part of an airway or route is unusable
because of NAVAID status. These routes consist of:
a. Substitute routes which are shown on U.S.
Government charts.
b. Routes defined by ATC as specific NAVAID
radials or courses.
c. Routes defined by ATC as direct to or between
NAVAIDs.
SUNSET AND SUNRISE- The mean solar times of
sunset and sunrise as published in the Nautical
Almanac, converted to local standard time for the
locality concerned. Within Alaska, the end of evening
civil twilight and the beginning of morning civil
twilight, as defined for each locality.
SUPER HIGH FREQUENCY- The frequency band
between 3 and 30 gigahertz (GHz). The elevation and
azimuth stations of the microwave landing system
operate from 5031 MHz to 5091 MHz in this
spectrum.
SUPPLEMENTAL WEATHER SERVICE LOCA©\
TION- Airport facilities staffed with contract
personnel who take weather observations and
provide current local weather to pilots via telephone
or radio. (All other services are provided by the parent
FSS.)
SUPPS- Refers to ICAO Document 7030 Regional
Supplementary Procedures. SUPPS contain proce©\
dures for each ICAO Region which are unique to that
Region and are not covered in the worldwide
provisions identified in the ICAO Air Navigation
Plan. Procedures contained in Chapter 8 are based in
part on those published in SUPPS.
SURFACE AREA- The airspace contained by the
lateral boundary of the Class B, C, D, or E airspace
designated for an airport that begins at the surface and
extends upward.
SURPIC- A description of surface vessels in the area
of a Search and Rescue incident including their
predicted positions and their characteristics.
(Refer to FAAO JO 7110.65, Para 10-6-4,
INFLIGHT CONTINGENCIES.)
SURVEILLANCE APPROACH- An instrument
approach wherein the air traffic controller issues
instructions, for pilot compliance, based on aircraft
Pilot/Controller Glossary 2/14/08
PCG S-8
position in relation to the final approach course
(azimuth), and the distance (range) from the end of
the runway as displayed on the controller's radar
scope. The controller will provide recommended
altitudes on final approach if requested by the pilot.
(Refer to AIM.)
SWAP(See SEVERE WEATHER AVOIDANCE PLAN.)
SWSL(See SUPPLEMENTAL WEATHER SERVICE
LOCATION.)
SYSTEM STRATEGIC NAVIGATION- Military
activity accomplished by navigating along a
preplanned route using internal aircraft systems to
maintain a desired track. This activity normally
requires a lateral route width of 10 NM and altitude
range of 1,000 feet to 6,000 feet AGL with some route
segments that permit terrain following.
Pilot/Controller Glossary 2/14/08
PCG T-1
T
TACAN(See TACTICAL AIR NAVIGATION.)
TACAN©\ONLY AIRCRAFT- An aircraft, normally
military, possessing TACAN with DME but no VOR
navigational system capability. Clearances must
specify TACAN or VORTAC fixes and approaches.
TACTICAL AIR NAVIGATION- An ultra©\high
frequency electronic rho©\theta air navigation aid
which provides suitably equipped aircraft a
continuous indication of bearing and distance to the
TACAN station.
(See VORTAC.)
(Refer to AIM.)
TAILWIND- Any wind more than 90 degrees to the
longitudinal axis of the runway. The magnetic
direction of the runway shall be used as the basis for
determining the longitudinal axis.
TAKEOFF AREA(See LANDING AREA.)
TAKE©\OFF DISTANCE AVAILABLE [ICAO]- The
length of the take©\off run available plus the length of
the clearway, if provided.
TAKE©\OFF RUN AVAILABLE [ICAO]- The length
of runway declared available and suitable for the
ground run of an aeroplane take©\off.
TARGET- The indication shown on an analog
display resulting from a primary radar return or a
radar beacon reply.
(See ASSOCIATED.)
(See DIGITAL TARGET.)
(See DIGITIZED RADAR TARGET.)
(See PRIMARY RADAR TARGET.)
(See RADAR.)
(See SECONDARY RADAR TARGET.)
(See TARGET SYMBOL.)
(See ICAO term TARGET.)
(See UNASSOCIATED.)
TARGET [ICAO]- In radar:
a. Generally, any discrete object which reflects or
retransmits energy back to the radar equipment.
b. Specifically, an object of radar search or
surveillance.
TARGET RESOLUTION- A process to ensure that
correlated radar targets do not touch. Target
resolution shall be applied as follows:
a. Between the edges of two primary targets or the
edges of the ASR©\9 primary target symbol.
b. Between the end of the beacon control slash and
the edge of a primary target.
c. Between the ends of two beacon control slashes.
Note 1:MANDATORY TRAFFIC ADVISORIES
AND SAFETY ALERTS SHALL BE ISSUED
WHEN THIS PROCEDURE IS USED.
Note 2:This procedure shall not be provided
utilizing mosaic radar systems.
TARGET SYMBOL- A computer©\generated indica©\
tion shown on a radar display resulting from a
primary radar return or a radar beacon reply.
TAS(See TERMINAL AUTOMATION SYSTEMS.)
TAWS(See TERRAIN AWARENESS WARNING
SYSTEM.)
TAXI- The movement of an airplane under its own
power on the surface of an airport (14 CFR
Section 135.100 [Note]). Also, it describes the
surface movement of helicopters equipped with
wheels.
(See AIR TAXI.)
(See HOVER TAXI.)
(Refer to 14 CFR Section 135.100.)
(Refer to AIM.)
TAXI PATTERNS- Patterns established to illustrate
the desired flow of ground traffic for the different
runways or airport areas available for use.
TCAS(See TRAFFIC ALERT AND COLLISION
AVOIDANCE SYSTEM.)
TCH(See THRESHOLD CROSSING HEIGHT.)
TCLT(See TENTATIVE CALCULATED LANDING
TIME.)
TDLS(See TERMINAL DATA LINK SYSTEM.)
Pilot/Controller Glossary 2/14/08
PCG T-2
TDZE(See TOUCHDOWN ZONE ELEVATION.)
TELEPHONE INFORMATION BRIEFING SER©\
VIC E- A continuous telephone recording of
meteorological and/or aeronautical information.
(Refer to AIM.)
TENTATIVE CALCULATED LANDING TIME- A
projected time calculated for adapted vertex for each
arrival aircraft based upon runway configuration,
airport acceptance rate, airport arrival delay period,
and other metered arrival aircraft. This time is either
the VTA of the aircraft or the TCLT/ACLT of the
previous aircraft plus the AAI, whichever is later.
This time will be updated in response to an aircraft's
progress and its current relationship to other arrivals.
TERMINAL AREA- A general term used to describe
airspace in which approach control service or airport
traffic control service is provided.
TERMINAL AREA FACILITY- A facility provid©\
ing air traffic control service for arriving and
departing IFR, VFR, Special VFR, and on occasion
en route aircraft.
(See APPROACH CONTROL FACILITY.)
(See TOWER.)
TERMINAL AUTOMATION SYSTEMS (TAS)-
TAS is used to identify the numerous automated
tracking systems including ARTS IIE, ARTS IIIA,
ARTS IIIE, STARS, and MEARTS.
TERMINAL DATA LINK SYSTEM (TDLS)- A
system that provides Digital Automatic Terminal
Information Service (D-ATIS) both on a specified
radio frequency and also, for subscribers, in a text
message via data link to the cockpit or to a gate
printer. TDLS also provides Pre-departure Clear©\
ances (PDC), at selected airports, to subscribers,
through a service provider, in text to the cockpit or to
a gate printer. In addition, TDLS will emulate the
Flight Data Input/Output (FDIO) information within
the control tower.
TERMINAL RADAR SERVICE AREA- Airspace
surrounding designated airports wherein ATC
provides radar vectoring, sequencing, and separation
on a full©\time basis for all IFR and participating VFR
aircraft. The AIM contains an explanation of TRSA.
TRSAs are depicted on VFR aeronautical charts.
Pilot participation is urged but is not mandatory.
TERMINAL VFR RADAR SERVICE- A national
program instituted to extend the terminal radar
services provided instrument flight rules (IFR)
aircraft to visual flight rules (VFR) aircraft. The
program is divided into four types service referred to
as basic radar service, terminal radar service area
(TRSA) service, Class B service and Class C service.
The type of service provided at a particular location
is contained in the Airport/Facility Directory.
a. Basic Radar Service- These services are
provided for VFR aircraft by all commissioned
terminal radar facilities. Basic radar service includes
safety alerts, traffic advisories, limited radar
vectoring when requested by the pilot, and
sequencing at locations where procedures have been
established for this purpose and/or when covered by
a letter of agreement. The purpose of this service is to
adjust the flow of arriving IFR and VFR aircraft into
the traffic pattern in a safe and orderly manner and to
provide traffic advisories to departing VFR aircraft.
b. TRSA Service- This service provides, in
addition to basic radar service, sequencing of all IFR
and participating VFR aircraft to the primary airport
and separation between all participating VFR
aircraft. The purpose of this service is to provide
separation between all participating VFR aircraft and
all IFR aircraft operating within the area defined as a
TRSA.
c. Class C Service- This service provides, in
addition to basic radar service, approved separation
between IFR and VFR aircraft, and sequencing of
VFR aircraft, and sequencing of VFR arrivals to the
primary airport.
d. Class B Service- This service provides, in
addition to basic radar service, approved separation
of aircraft based on IFR, VFR, and/or weight, and
sequencing of VFR arrivals to the primary airport(s).
(See CONTROLLED AIRSPACE.)
(See TERMINAL RADAR SERVICE AREA.)
(Refer to AIM.)
(Refer to AIRPORT/FACILITY DIRECTORY.)
TERMINAL©\VERY HIGH FREQUENCY OMNI©\
DIRECTIONAL RANGE STATION- A very high
frequency terminal omnirange station located on or
near an airport and used as an approach aid.
(See NAVIGATIONAL AID.)
(See VOR.)
TERRAIN AWARENESS WARNING SYSTEM
(TAWS)- An on-board, terrain proximity alerting
Pilot/Controller Glossary 2/14/08
PCG T-3
system providing the aircrew `Low Altitude
warnings' to allow immediate pilot action.
TERRAIN FOLLOWING- The flight of a military
aircraft maintaining a constant AGL altitude above
the terrain or the highest obstruction. The altitude of
the aircraft will constantly change with the varying
terrain and/or obstruction.
TETRAHEDRON- A device normally located on
uncontrolled airports and used as a landing direction
indicator. The small end of a tetrahedron points in the
direction of landing. At controlled airports, the
tetrahedron, if installed, should be disregarded
because tower instructions supersede the indicator.
(See SEGMENTED CIRCLE.)
(Refer to AIM.)
TF(See TERRAIN FOLLOWING.)
THAT IS CORRECT- The understanding you have
is right.
360 OVERHEAD(See OVERHEAD MANEUVER.)
THRESHOLD- The beginning of that portion of the
runway usable for landing.
(See AIRPORT LIGHTING.)
(See DISPLACED THRESHOLD.)
THRESHOLD CROSSING HEIGHT- The theoreti©\
cal height above the runway threshold at which the
aircraft's glideslope antenna would be if the aircraft
maintains the trajectory established by the mean ILS
glideslope or MLS glidepath.
(See GLIDESLOPE.)
(See THRESHOLD.)
THRESHOLD LIGHTS(See AIRPORT LIGHTING.)
TIBS(See TELEPHONE INFORMATION BRIEFING
SERVICE.)
TIME GROUP- Four digits representing the hour
and minutes from the Coordinated Universal Time
(UTC) clock. FAA uses UTC for all operations. The
term ¡°ZULU¡± may be used to denote UTC. The word
¡°local¡± or the time zone equivalent shall be used to
denote local when local time is given during radio and
telephone communications. When written, a time
zone designator is used to indicate local time; e.g.
¡°0205M¡± (Mountain). The local time may be based
on the 24©\hour clock system. The day begins at 0000
and ends at 2359.
TMA(See TRAFFIC MANAGEMENT ADVISOR.)
TMPA(See TRAFFIC MANAGEMENT PROGRAM
ALERT.)
TMU(See TRAFFIC MANAGEMENT UNIT.)
TODA [ICAO]-
(See ICAO Term TAKE©\OFF DISTANCE
AVAILABLE.)
TORA [ICAO]-
(See ICAO Term TAKE©\OFF RUN AVAILABLE.)
TORCHING- The burning of fuel at the end of an
exhaust pipe or stack of a reciprocating aircraft
engine, the result of an excessive richness in the fuel
air mixture.
TOTAL ESTIMATED ELAPSED TIME [ICAO]-
For IFR flights, the estimated time required from
take©\off to arrive over that designated point, defined
by reference to navigation aids, from which it is
intended that an instrument approach procedure will
be commenced, or, if no navigation aid is associated
with the destination aerodrome, to arrive over the
destination aerodrom e. For VFR flights, the
estimated time required from take©\off to arrive over
the destination aerodrome.
(See ICAO term ESTIMATED ELAPSED TIME.)
TOUCH©\AND©\GO- An operation by an aircraft that
lands and departs on a runway without stopping or
exiting the runway.
TOUCH©\AND©\GO LANDING(See TOUCH©\AND©\GO.)
TOUCHDOWNa. The point at which an aircraft first makes
contact with the landing surface.
b. Concerning a precision radar approach (PAR),
it is the point where the glide path intercepts the
landing surface.
(See ICAO term TOUCHDOWN.)
Pilot/Controller Glossary 2/14/08
PCG T-4
TOUCHDOWN [ICAO]- The point where the
nominal glide path intercepts the runway.
Note:Touchdown as defined above is only a datum
and is not necessarily the actual point at which the
aircraft will touch the runway.
TOUCHDOWN RVR(See VISIBILITY.)
TOUCHDOWN ZONE- The first 3,000 feet of the
runway beginning at the threshold. The area is used
for determination of Touchdown Zone Elevation in
the development of straight©\in landing minimums for
instrument approaches.
(See ICAO term TOUCHDOWN ZONE.)
TOUCHDOWN ZONE [ICAO]- The portion of a
runway, beyond the threshold, where it is intended
landing aircraft first contact the runway.
TOUCHDOWN ZONE ELEVATION- The highest
elevation in the first 3,000 feet of the landing surface.
TDZE is indicated on the instrument approach
procedure chart when straight©\in landing minimums
are authorized.
(See TOUCHDOWN ZONE.)
TOUCHDOWN ZONE LIGHTING(See AIRPORT LIGHTING.)
TOWER- A terminal facility that uses air/ground
communications, visual signaling, and other devices
to provide ATC services to aircraft operating in the
vicinity of an airport or on the movement area.
Authorizes aircraft to land or takeoff at the airport
controlled by the tower or to transit the Class D
airspace area regardless of flight plan or weather
conditions (IFR or VFR). A tower may also provide
approach control services (radar or nonradar).
(See AIRPORT TRAFFIC CONTROL SERVICE.)
(See APPROACH CONTROL FACILITY.)
(See APPROACH CONTROL SERVICE.)
(See MOVEMENT AREA.)
(See TOWER EN ROUTE CONTROL
SERVICE.)
(See ICAO term AERODROME CONTROL
TOWER.)
(Refer to AIM.)
TOWER EN ROUTE CONTROL SERVICE- The
control of IFR en route traffic within delegated
airspace between two or more adjacent approach
control facilities. This service is designed to expedite
traffic and reduce control and pilot communication
requirements.
TOWER TO TOWER(See TOWER EN ROUTE CONTROL
SERVICE.)
TPX©\42- A numeric beacon decoder equipment/
system. It is designed to be added to terminal radar
systems for beacon decoding. It provides rapid target
identification, reinforcement of the primary radar
target, and altitude information from Mode C.
(See AUTOMATED RADAR TERMINAL
SYSTEMS.)
(See TRANSPONDER.)
TRACEABLE PRESSURE STANDARD- The
facility station pressure instrument, with certifica©\
tion/calibration traceable to the National Institute of
Standards and Technology. Traceable pressure
standards may be mercurial barometers, commis©\
sioned ASOS or dual transducer AWOS, or portable
pressure standards or DASI.
TRACK- The actual flight path of an aircraft over the
surface of the earth.
(See COURSE.)
(See FLIGHT PATH.)
(See ROUTE.)
(See ICAO term TRACK.)
TRACK [ICAO]- The projection on the earth's
surface of the path of an aircraft, the direction of
which path at any point is usually expressed in
degrees from North (True, Magnetic, or Grid).
TRAFFICa. A term used by a controller to transfer radar
identification of an aircraft to another controller for
the purpose of coordinating separation action. Traffic
is normally issued:
1. In response to a handoff or point out,
2. In anticipation of a handoff or point out, or
3. In conjunction with a request for control of an
aircraft.
b. A term used by ATC to refer to one or more
aircraft.
TRAFFIC ADVISORIES- Advisories issued to alert
pilots to other known or observed air traffic which
may be in such proximity to the position or intended
route of flight of their aircraft to warrant their
attention. Such advisories may be based on:
a. Visual observation.
Pilot/Controller Glossary 2/14/08
PCG T-5
b. Observation of radar identified and nonidenti©\
fied aircraft targets on an ATC radar display, or
c. Verbal reports from pilots or other facilities.
Note 1:The word ¡°traffic¡± followed by additional
information, if known, is used to provide such
advisories; e.g., ¡°Traffic, 2 o'clock, one zero miles,
southbound, eight thousand.¡±
Note 2:Traffic advisory service will be provided to
the extent possible depending on higher priority
duties of the controller or other limitations; e.g.,
radar limitations, volume of traffic, frequency
congestion, or controller workload. Radar/
nonradar traffic advisories do not relieve the pilot
of his/her responsibility to see and avoid other
aircraft. Pilots are cautioned that there are many
times when the controller is not able to give traffic
advisories concerning all traffic in the aircraft's
proximity; in other words, when a pilot requests or
is receiving traffic advisories, he/she should not
assume that all traffic will be issued.
(Refer to AIM.)
TRAFFIC ALERT (aircraft call sign), TURN
(left/right) IMMEDIATELY, (climb/descend) AND
MAINTAIN (altitude).
(See SAFETY ALERT.)
TRAFFIC ALERT AND COLLISION AVOID©\
ANCE SYSTEM- An airborne collision avoidance
system based on radar beacon signals which operates
independent of ground©\based equipment. TCAS©\I
generates traffic advisories only. TCAS©\II generates
traffic advisories, and resolution (collision avoid©\
ance) advisories in the vertical plane.
TRAFFIC INFORMATION(See TRAFFIC ADVISORIES.)
TRAFFIC IN SIGHT- Used by pilots to inform a
controller that previously issued traffic is in sight.
(See NEGATIVE CONTACT.)
(See TRAFFIC ADVISORIES.)
TRAFFIC MANAGEMENT ADVISOR (TMA)- A
computerized tool which assists Traffic Management
Coordinators to efficiently schedule arrival traffic to
a metered airport, by calculating meter fix times and
delays then sending that information to the sector
controllers.
TRAFFIC MANAGEMENT PROGRAM ALERT-
A term used in a Notice to Airmen (NOTAM) issued
in conjunction with a special traffic management
program to alert pilots to the existence of the program
and to refer them to either the Notices to Airmen
publication or a special traffic management program
advisory message for program details. The contrac©\
tion TMPA is used in NOTAM text.
TRAFFIC MANAGEMENT UNIT- The entity in
ARTCCs and designated terminals directly involved
in the active management of facility traffic. Usually
under the direct supervision of an assistant manager
for traffic management.
TRAFFIC NO FACTOR- Indicates that the traffic
described in a previously issued traffic advisory is no
factor.
TRAFFIC NO LONGER OBSERVED- Indicates
that the traffic described in a previously issued traffic
advisory is no longer depicted on radar, but may still
be a factor.
TRAFFIC PATTERN- The traffic flow that is
prescribed for aircraft landing at, taxiing on, or taking
off from an airport. The components of a typical
traffic pattern are upwind leg, crosswind leg,
downwind leg, base leg, and final approach.
a. Upwind Leg- A flight path parallel to the
landing runway in the direction of landing.
b. Crosswind Leg- A flight path at right angles to
the landing runway off its upwind end.
c. Downwind Leg- A flight path parallel to the
landing runway in the direction opposite to landing.
The downwind leg normally extends between the
crosswind leg and the base leg.
d. Base Leg- A flight path at right angles to the
landing runway off its approach end. The base leg
normally extends from the downwind leg to the
intersection of the extended runway centerline.
e. Final Approach. A flight path in the direction of
landing along the extended runway centerline. The
final approach normally extends from the base leg to
the runway. An aircraft making a straight©\in approach
VFR is also considered to be on final approach.
(See STRAIGHT©\IN APPROACH VFR.)
(See TAXI PATTERNS.)
(See ICAO term AERODROME TRAFFIC
CIRCUIT.)
(Refer to 14 CFR Part 91.)
(Refer to AIM.)
TRAFFIC SITUATION DISPLAY (TSD)- TSD is a
computer system that receives radar track data from
all 20 CONUS ARTCCs, organizes this data into a
mosaic display, and presents it on a computer screen.
Pilot/Controller Glossary 2/14/08
PCG T-6
The display allows the traffic management coordina©\
tor multiple methods of selection and highlighting of
individual aircraft or groups of aircraft. The user has
the option of superimposing these aircraft positions
over any number of background displays. These
background options include ARTCC boundaries, any
stratum of en route sector boundaries, fixes, airways,
military and other special use airspace, airports, and
geopolitical boundaries. By using the TSD, a
coordinator can monitor any number of traffic
situations or the entire systemwide traffic flows.
TRAJECTORY- A URET representation of the path
an aircraft is predicted to fly based upon a Current
Plan or Trial Plan.
(See USER REQUEST EVALUATION TOOL.)
TRAJECTORY MODELING- The automated pro©\
cess of calculating a trajectory.
TRANSCRIBED WEATHER BROADCAST- A
continuous recording of meteorological and aeronau©\
tical information that is broadcast on L/MF and VOR
facilities for pilots. (Provided only in Alaska.)
(Refer to AIM.)
TRANSFER OF CONTROL- That action whereby
the responsibility for the separation of an aircraft is
transferred from one controller to another.
(See ICAO term TRANSFER OF CONTROL.)
TRANSFER OF CONTROL [ICAO]- Transfer of
responsibility for providing air traffic control service.
TRANSFERRING CONTROLLER- A controller/
facility transferring control of an aircraft to another
controller/facility.
(See ICAO term TRANSFERRING
UNIT/CONTROLLER.)
TRANSFERRING FACILITY(See TRANSFERRING CONTROLLER.)
TRANSFERRING UNIT/CONTROLLER [ICAO]-
Air traffic control unit/air traffic controller in the
process of transferring the responsibility for
providing air traffic control service to an aircraft to
the next air traffic control unit/air traffic controller
along the route of flight.
Note:See definition of accepting unit/controller.
TRANSITIONa. The general term that describes the change from
one phase of flight or flight condition to another; e.g.,
transition from en route flight to the approach or
transition from instrument flight to visual flight.
b. A published procedure (DP Transition) used to
connect the basic DP to one of several en route
airways/jet routes, or a published procedure (STAR
Transition) used to connect one of several en route
airways/jet routes to the basic STAR.
(Refer to DP/STAR Charts.)
TRANSITION POINT- A point at an adapted
number of miles from the vertex at which an arrival
aircraft would normally commence descent from its
en route altitude. This is the first fix adapted on the
arrival speed segments.
TRANSITION WAYPOINT- The waypoint that
defines the beginning of a runway or en route
transition on an RNAV SID or STAR.
TRANSITIONAL AIRSPACE- That portion of
controlled airspace wherein aircraft change from one
phase of flight or flight condition to another.
TRANSMISSOMETER- An apparatus used to
determine visibility by measuring the transmission of
light through the atmosphere. It is the measurement
source for determining runway visual range (RVR)
and runway visibility value (RVV).
(See VISIBILITY.)
TRANSMITTING IN THE BLIND- A transmis©\
sion from one station to other stations in
circumstances where two©\way communication
cannot be established, but where it is believed that the
called stations may be able to receive the
transmission.
TRANSPONDER- The airborne radar beacon
receiver/transmitter portion of the Air Traffic Control
Radar Beacon System (ATCRBS) which automati©\
cally receives radio signals from interrogators on the
ground, and selectively replies with a specific reply
pulse or pulse group only to those interrogations
being received on the mode to which it is set to
respond.
(See INTERROGATOR.)
(See ICAO term TRANSPONDER.)
(Refer to AIM.)
TRANSPONDER [ICAO]- A receiver/transmitter
which will generate a reply signal upon proper
interrogation; the interrogation and reply being on
different frequencies.
TRANSPONDER CODES(See CODES.)
Pilot/Controller Glossary 2/14/08
PCG T-7
TRIAL PLAN- A proposed amendment which
utilizes automation to analyze and display potential
conflicts along the predicted trajectory of the selected
aircraft.
TRSA(See TERMINAL RADAR SERVICE AREA.)
TSD(See TRAFFIC SITUATION DISPLAY.)
TURBOJET AIRCRAFT- An aircraft having a jet
engine in which the energy of the jet operates a
turbine which in turn operates the air compressor.
TURBOPROP AIRCRAFT- An aircraft having a jet
engine in which the energy of the jet operates a
turbine which drives the propeller.
TURN ANTICIPATION- (maneuver anticipation).
TVOR(See TERMINAL©\VERY HIGH FREQUENCY
OMNIDIRECTIONAL RANGE STATION.)
TWEB(See TRANSCRIBED WEATHER BROADCAST.)
TWO©\WAY RADIO COMMUNICATIONS FAIL©\
URE(See LOST COMMUNICATIONS.)
Pilot/Controller Glossary 2/14/08
PCG U-1
U
UDF(See DIRECTION FINDER.)
UHF(See ULTRAHIGH FREQUENCY.)
ULTRAHIGH FREQUENCY- The frequency band
between 300 and 3,000 MHz. The bank of radio
frequencies used for military air/ground voice
communications. In some instances this may go as
low as 225 MHz and still be referred to as UHF.
ULTRALIGHT VEHICLE- An aeronautical vehicle
operated for sport or recreational purposes which
does not require FAA registration, an airworthiness
certificate, nor pilot certification. They are primarily
single occupant vehicles, although some two©\place
vehicles are authorized for training purposes.
Operation of an ultralight vehicle in certain airspace
requires authorization from ATC.
(Refer to 14 CFR Part 103.)
UNABLE- Indicates inability to comply with a
specific instruction, request, or clearance.
UNASSOCIATED- A radar target that does not
display a data block with flight identification and
altitude information.
(See ASSOCIATED.)
UNDER THE HOOD- Indicates that the pilot is
using a hood to restrict visibility outside the cockpit
while simulating instrument flight. An appropriately
rated pilot is required in the other control seat while
this operation is being conducted.
(Refer to 14 CFR Part 91.)
UNFROZEN- The Scheduled Time of Arrival (STA)
tags, which are still being rescheduled by traffic
management advisor (TMA) calculations. The
aircraft will remain unfrozen until the time the
corresponding estimated time of arrival (ETA) tag
passes the preset freeze horizon for that aircraft's
stream class. At this point the automatic rescheduling
will stop, and the STA becomes ¡°frozen.¡±
UNICOM- A nongovernment communication facil©\
ity which may provide airport information at certain
airports. Locations and frequencies of UNICOMs are
shown on aeronautical charts and publications.
(See AIRPORT/FACILITY DIRECTORY.)
(Refer to AIM.)
UNPUBLISHED ROUTE- A route for which no
minimum altitude is published or charted for pilot
use. It may include a direct route between NAVAIDs,
a radial, a radar vector, or a final approach course
beyond the segments of an instrument approach
procedure.
(See PUBLISHED ROUTE.)
(See ROUTE.)
UNRELIABLE (GPS/WAAS)- An advisory to
pilots indicating the expected level of service of the
GPS and/or WAAS may not be available. Pilots must
then determine the adequacy of the signal for desired
use.
UPWIND LEG(See TRAFFIC PATTERN.)
URET(See USER REQUEST EVALUATION TOOL.)
URGENCY- A condition of being concerned about
safety and of requiring timely but not immediate
assistance; a potential distress condition.
(See ICAO term URGENCY.)
URGENCY [ICAO]- A condition concerning the
safety of an aircraft or other vehicle, or of person on
board or in sight, but which does not require
immediate assistance.
USAFIB(See ARMY AVIATION FLIGHT INFORMATION
BULLETIN.)
USER REQUEST EVALUATION TOOL (URET)-
User Request Evaluation Tool is an automated tool
provided at each Radar Associate position in selected
En Route facilities. This tool utilizes flight and radar
data to determine present and future trajectories for
all active and proposal aircraft and provides
enhanced, automated flight data management.
UVDF(See DIRECTION FINDER.)
Pilot/Controller Glossary 2/14/08
PCG V-1
V
VASI(See VISUAL APPROACH SLOPE INDICATOR.)
VCOA(See VISUAL CLIMB OVER AIRPORT.)
VDF(See DIRECTION FINDER.)
VDP(See VISUAL DESCENT POINT.)
VECTOR- A heading issued to an aircraft to provide
navigational guidance by radar.
(See ICAO term RADAR VECTORING.)
VERIFY- Request confirmation of information;
e.g., ¡°verify assigned altitude.¡±
VERIFY SPECIFIC DIRECTION OF TAKEOFF
(OR TURNS AFTER TAKEOFF)- Used by ATC to
ascertain an aircraft's direction of takeoff and/or
direction of turn after takeoff. It is normally used for
IFR departures from an airport not having a control
tower. When direct communication with the pilot is
not possible, the request and information may be
relayed through an FSS, dispatcher, or by other
means.
(See IFR TAKEOFF MINIMUMS AND
DEPARTURE PROCEDURES.)
VERTEX- The last fix adapted on the arrival speed
segments. Normally, it will be the outer marker of the
runway in use. However, it may be the actual
threshold or other suitable common point on the
approach path for the particular runway configura©\
tion.
VERTEX TIME OF ARRIVAL- A calculated time of
aircraft arrival over the adapted vertex for the runway
configuration in use. The time is calculated via the
optimum flight path using adapted speed segments.
VERTICAL NAVIGATION (VNAV)¨C A function of
area navigation (RNAV) equipment which calculates,
displays, and provides vertical guidance to a profile
or path.
VERTICAL SEPARATION- Separation established
by assignment of different altitudes or flight levels.
(See SEPARATION.)
(See ICAO term VERTICAL SEPARATION.)
VERTICAL SEPARATION [ICAO]- Separation
between aircraft expressed in units of vertical
distance.
VERTICAL TAKEOFF AND LANDING AIR©\
CRAFT- Aircraft capable of vertical climbs and/or
descents and of using very short runways or small
areas for takeoff and landings. These aircraft include,
but are not limited to, helicopters.
(See SHORT TAKEOFF AND LANDING
AIRCRAFT.)
VERY HIGH FREQUENCY- The frequency band
between 30 and 300 MHz. Portions of this band, 108
to 118 MHz, are used for certain NAVAIDs; 118 to
136 MHz are used for civil air/ground voice
communications. Other frequencies in this band are
used for purposes not related to air traffic control.
VERY HIGH FREQUENCY OMNIDIRECTION©\
AL RANGE STATION(See VOR.)
VERY LOW FREQUENCY- The frequency band
between 3 and 30 kHz.
VFR(See VISUAL FLIGHT RULES.)
VFR AIRCRAFT- An aircraft conducting flight in
accordance with visual flight rules.
(See VISUAL FLIGHT RULES.)
VFR CONDITIONS- Weather conditions equal to
or better than the minimum for flight under visual
flight rules. The term may be used as an ATC
clearance/instruction only when:
a. An IFR aircraft requests a climb/descent in
VFR conditions.
b. The clearance will result in noise abatement
benefits where part of the IFR departure route does
not conform to an FAA approved noise abatement
route or altitude.
c. A pilot has requested a practice instrument
approach and is not on an IFR flight plan.
Note:All pilots receiving this authorization must
comply with the VFR visibility and distance from
cloud criteria in 14 CFR Part 91. Use of the term
does not relieve controllers of their responsibility to
separate aircraft in Class B and Class C airspace
or TRSAs as required by FAAO JO 7110.65. When
Pilot/Controller Glossary 2/14/08
PCG V-2
used as an ATC clearance/instruction, the term
may be abbreviated ¡°VFR;¡± e.g., ¡°MAINTAIN
VFR,¡± ¡°CLIMB/DESCEND VFR,¡± etc.
VFR FLIGHT(See VFR AIRCRAFT.)
VFR MILITARY TRAINING ROUTES- Routes
used by the Department of Defense and associated
Reserve and Air Guard units for the purpose of
conducting low©\altitude navigation and tactical
training under VFR below 10,000 feet MSL at
airspeeds in excess of 250 knots IAS.
VFR NOT RECOMMENDED- An advisory
provided by a flight service station to a pilot during
a preflight or inflight weather briefing that flight
under visual flight rules is not recommended. To be
given when the current and/or forecast weather
conditions are at or below VFR minimums. It does
not abrogate the pilot's authority to make his/her own
decision.
VFR©\ON©\TOP- ATC authorization for an IFR
aircraft to operate in VFR conditions at any
appropriate VFR altitude (as specified in 14 CFR and
as restricted by ATC). A pilot receiving this
authorization must comply with the VFR visibility,
distance from cloud criteria, and the minimum IFR
altitudes specified in 14 CFR Part 91. The use of this
term does not relieve controllers of their responsibil©\
ity to separate aircraft in Class B and Class C airspace
or TRSAs as required by FAAO JO 7110.65.
VFR TERMINAL AREA CHARTS(See AERONAUTICAL CHART.)
VFR WAYPOINT(See WAYPOINT.)
VHF(See VERY HIGH FREQUENCY.)
VHF OMNIDIRECTIONAL RANGE/TACTICAL
AIR NAVIGATION(See VORTAC.)
VIDEO MAP- An electronically displayed map on
the radar display that may depict data such as airports,
heliports, runway centerline extensions, hospital
emergency landing areas, NAVAIDs and fixes,
reporting points, airway/route centerlines, bound©\
aries, handoff points, special use tracks, obstructions,
prominent geographic features, map alignment
indicators, range accuracy marks, minimum vector©\
ing altitudes.
VIS IBILITY- The ability, as determ ined by
atmospheric conditions and expressed in units of
distance, to see and identify prominent unlighted
objects by day and prominent lighted objects by
night. Visibility is reported as statute miles, hundreds
of feet or meters.
(Refer to 14 CFR Part 91.)
(Refer to AIM.)
a. Flight Visibility- The average forward horizon©\
tal distance, from the cockpit of an aircraft in flight,
at which prominent unlighted objects may be seen
and identified by day and prominent lighted objects
may be seen and identified by night.
b. Ground Visibility- Prevailing horizontal visi©\
bility near the earth's surface as reported by the
United States National Weather Service or an
accredited observer.
c. Prevailing Visibility- The greatest horizontal
visibility equaled or exceeded throughout at least half
the horizon circle which need not necessarily be
continuous.
d. Runway Visibility Value (RVV)- The visibility
determined for a particular runway by a transmis©\
someter. A meter provides a continuous indication of
the visibility (reported in miles or fractions of miles)
for the runway. RVV is used in lieu of prevailing
visibility in determining minimums for a particular
runway.
e. Runway Visual Range (RVR)- An instrumen©\
tally derived value, based on standard calibrations,
that represents the horizontal distance a pilot will see
down the runway from the approach end. It is based
on the sighting of either high intensity runway lights
or on the visual contrast of other targets whichever
yields the greater visual range. RVR, in contrast to
prevailing or runway visibility, is based on what a
pilot in a moving aircraft should see looking down the
runway. RVR is horizontal visual range, not slant
visual range. It is based on the measurement of a
transmissometer made near the touchdown point of
the instrument runway and is reported in hundreds of
feet. RVR is used in lieu of RVV and/or prevailing
visibility in determining minimums for a particular
runway.
1. Touchdown RVR- The RVR visibility
readout values obtained from RVR equipment
serving the runway touchdown zone.
Pilot/Controller Glossary 2/14/08
PCG V-3
2. Mid©\RVR- The RVR readout values obtained
from RVR equipment located midfield of the runway.
3. Rollout RVR- The RVR readout values
obtained from RVR equipment located nearest the
rollout end of the runway.
(See ICAO term FLIGHT VISIBILITY.)
(See ICAO term GROUND VISIBILITY.)
(See ICAO term RUNWAY VISUAL RANGE.)
(See ICAO term VISIBILITY.)
VISIBILITY [ICAO]- The ability, as determined by
atmospheric conditions and expressed in units of
distance, to see and identify prominent unlighted
objects by day and prominent lighted objects by
night.
a. Flight Visibility-The visibility forward from
the cockpit of an aircraft in flight.
b. Ground Visibility-The visibility at an aero©\
drome as reported by an accredited observer.
c. Runway Visual Range [RVR]-The range over
which the pilot of an aircraft on the centerline of a
runway can see the runway surface markings or the
lights delineating the runway or identifying its
centerline.
VISUAL APPROACH- An approach conducted on
an instrument flight rules (IFR) flight plan which
authorizes the pilot to proceed visually and clear of
clouds to the airport. The pilot must, at all times, have
either the airport or the preceding aircraft in sight.
This approach must be authorized and under the
control of the appropriate air traffic control facility.
Reported weather at the airport must be ceiling at or
above 1,000 feet and visibility of 3 miles or greater.
(See ICAO term VISUAL APPROACH.)
VISUAL APPROACH [ICAO]- An approach by an
IFR flight when either part or all of an instrument
approach procedure is not completed and the
approach is executed in visual reference to terrain.
VISUAL APPROACH SLOPE INDICATOR(See AIRPORT LIGHTING.)
VISUAL CLIMB OVER AIRPORT (VCOA)- A
departure option for an IFR aircraft, operating in
visual meteorological conditions equal to or greater
than the specified visibility and ceiling, to visually
conduct climbing turns over the airport to the
published ¡°climb-to¡± altitude from which to proceed
with the instrument portion of the departure. VCOA
procedures are developed to avoid obstacles greater
than 3 statute miles from the departure end of the
runway as an alternative to complying with climb
gradients greater than 200 feet per nautical mile.
These procedures are published in the `Take-Off
Minimums and (Obstacle) Departure Procedures'
section of the Terminal Procedures Publications.
(See AIM.)
VISUAL DESCENT POINT- A defined point on the
final approach course of a nonprecision straight©\in
approach procedure from which normal descent from
the MDA to the runway touchdown point may be
commenced, provided the approach threshold of that
runway, or approach lights, or other markings
identifiable with the approach end of that runway are
clearly visible to the pilot.
VISUAL FLIGHT RULES- Rules that govern the
procedures for conducting flight under visual
conditions. The term ¡°VFR¡± is also used in the
United States to indicate weather conditions that are
equal to or greater than minimum VFR requirements.
In addition, it is used by pilots and controllers to
indicate type of flight plan.
(See INSTRUMENT FLIGHT RULES.)
(See INSTRUMENT METEOROLOGICAL
CONDITIONS.)
(See VISUAL METEOROLOGICAL
CONDITIONS.)
(Refer to 14 CFR Part 91.)
(Refer to AIM.)
VISUAL HOLDING- The holding of aircraft at
selected, prominent geographical fixes which can be
easily recognized from the air.
(See HOLDING FIX.)
VISUAL METEOROLOGICAL CONDITIONS-
Meteorological conditions expressed in terms of
visibility, distance from cloud, and ceiling equal to or
better than specified minima.
(See INSTRUMENT FLIGHT RULES.)
(See INSTRUMENT METEOROLOGICAL
CONDITIONS.)
(See VISUAL FLIGHT RULES.)
VISUAL SEPARATION- A means employed by
ATC to separate aircraft in terminal areas and en route
airspace in the NAS. There are two ways to effect this
separation:
a. The tower controller sees the aircraft involved
and issues instructions, as necessary, to ensure that
the aircraft avoid each other.
b. A pilot sees the other aircraft involved and upon
instructions from the controller provides his/her own
Pilot/Controller Glossary 2/14/08
PCG V-4
separation by maneuvering his/her aircraft as
necessary to avoid it. This may involve following
another aircraft or keeping it in sight until it is no
longer a factor.
(See SEE AND AVOID.)
(Refer to 14 CFR Part 91.)
VLF(See VERY LOW FREQUENCY.)
VMC(See VISUAL METEOROLOGICAL
CONDITIONS.)
VOICE SWITCHING AND CONTROL SYSTEM-
The VSCS is a computer controlled switching system
that provides air traffic controllers with all voice
circuits (air to ground and ground to ground)
necessary for air traffic control.
(See VOICE SWITCHING AND CONTROL
SYSTEM.)
(Refer to AIM.)
VOR- A ground©\based electronic navigation aid
transmitting very high frequency navigation signals,
360 degrees in azimuth, oriented from magnetic
north. Used as the basis for navigation in the National
Airspace System. The VOR periodically identifies
itself by Morse Code and may have an additional
voice identification feature. Voice features may be
used by ATC or FSS for transmitting instructions/
information to pilots.
(See NAVIGATIONAL AID.)
(Refer to AIM.)
VOR TEST SIGNAL(See VOT.)
VORTAC- A navigation aid providing VOR
azimuth, TACAN azimuth, and TACAN distance
measuring equipment (DME) at one site.
(See DISTANCE MEASURING EQUIPMENT.)
(See NAVIGATIONAL AID.)
(See TACAN.)
(See VOR.)
(Refer to AIM.)
VORTICES- Circular patterns of air created by the
movem ent of an airfoil through the air when
generating lift. As an airfoil moves through the
atmosphere in sustained flight, an area of area of low
pressure is created above it. The air flowing from the
high pressure area to the low pressure area around and
about the tips of the airfoil tends to roll up into two
rapidly rotating vortices, cylindrical in shape. These
vortices are the most predominant parts of aircraft
wake turbulence and their rotational force is
dependent upon the wing loading, gross weight, and
speed of the generating aircraft. The vortices from
medium to heavy aircraft can be of extremely high
velocity and hazardous to smaller aircraft.
(See AIRCRAFT CLASSES.)
(See WAKE TURBULENCE.)
(Refer to AIM.)
VOT- A ground facility which emits a test signal to
check VOR receiver accuracy. Some VOTs are
available to the user while airborne, and others are
limited to ground use only.
(See AIRPORT/FACILITY DIRECTORY.)
(Refer to 14 CFR Part 91.)
(Refer to AIM.)
VR(See VFR MILITARY TRAINING ROUTES.)
VSCS(See VOICE SWITCHING AND CONTROL
SYSTEM.)
VTA(See VERTEX TIME OF ARRIVAL.)
VTOL AIRCRAFT(See VERTICAL TAKEOFF AND LANDING
AIRCRAFT.)
Pilot/Controller Glossary 2/14/08
PCG W-1
W
WA(See AIRMET.)
(See WEATHER ADVISORY.)
WAAS(See WIDE©\AREA AUGMENTATION SYSTEM.)
WAKE TURBULENCE- Phenomena resulting from
the passage of an aircraft through the atmosphere.
The term includes vortices, thrust stream turbulence,
jet blast, jet wash, propeller wash, and rotor wash
both on the ground and in the air.
(See AIRCRAFT CLASSES.)
(See JET BLAST.)
(See VORTICES.)
(Refer to AIM.)
WARNING AREA(See SPECIAL USE AIRSPACE.)
WAYPOINT- A predetermined geographical posi©\
tion used for route/instrument approach definition,
progress reports, published VFR routes, visual
reporting points or points for transitioning and/or
circumnavigating controlled and/or special use
airspace, that is defined relative to a VORTAC station
or in terms of latitude/longitude coordinates.
WEATHER ADVISORY- In aviation weather
forecast practice, an expression of hazardous weather
conditions not predicted in the area forecast, as they
affect the operation of air traffic and as prepared by
the NWS.
(See AIRMET.)
(See SIGMET.)
WHEN ABLE- When used in conjunction with ATC
instructions, gives the pilot the latitude to delay
compliance until a condition or event has been
reconciled. Unlike ¡°pilot discretion,¡± when instruc©\
tions are prefaced ¡°when able,¡± the pilot is expected
to seek the first opportunity to comply. Once a
maneuver has been initiated, the pilot is expected to
continue until the specifications of the instructions
have been met. ¡°When able,¡± should not be used
when expeditious compliance is required.
WIDE©\AREA AUGMENTATION SYSTEM
(WAAS)- The WAAS is a satellite navigation system
consisting of the equipment and software which
augments the GPS Standard Positioning Service
(SPS). The WAAS provides enhanced integrity,
accuracy, availability, and continuity over and above
GPS SPS. The differential correction function
provides improved accuracy required for precision
approach.
WILCO- I have received your message, understand
it, and will comply with it.
WIND GRID DISPLAY- A display that presents the
latest forecasted wind data overlaid on a map of the
ARTCC area. Wind data is automatically entered and
updated periodically by transmissions from the
National Weather Service. Winds at specific
altitudes, along with temperatures and air pressure
can be viewed.
WIND SHEAR- A change in wind speed and/or wind
direction in a short distance resulting in a tearing or
shearing effect. It can exist in a horizontal or vertical
direction and occasionally in both.
WING TIP VORTICES(See VORTICES.)
WORDS TWICEa. As a request: ¡°Communication is difficult.
Please say every phrase twice.¡±
b. As information: ¡°Since communications are
difficult, every phrase in this message will be spoken
twice.¡±
WORLD AERONAUTICAL CHARTS(See AERONAUTICAL CHART.)
WS(See SIGMET.)
(See WEATHER ADVISORY.)
WST(See CONVECTIVE SIGMET.)
(See WEATHER ADVISORY.)
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