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 - 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 - 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. PAR. 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 - 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 - 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 - 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) - 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 - 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 instrum ent 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
- 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 - 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 - 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. Precision 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. Precision 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. Precision 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
- 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 - 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 - 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. Pacific 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 - 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 - 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)– 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 - 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 - 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 - 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 instrum ent 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 27_N 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 60_W and south
of 38_30'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 - 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 - 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) - 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 - 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 - 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 - 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 - 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 -
(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
