TOUCHDOWN - 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 - 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 - 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 - 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 -
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 - 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 - 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)– 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 - 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 - 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 -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 - 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.)
7/31/08 AIM
Index I-1
INDEX
A
Abbreviations/Acronyms, Appendix 4-1
Accident, Aircraft, Reporting, 7-6-1
Accident Cause Factors, 7-5-1
Adherence to Clearance, 4-4-5
ADIZ. See Air Defense Identification Zones
ADS-B. See Automatic Dependent
Surveillance-Broadcast
Advisories
Braking Action, 4-3-7
Inflight Aviation Weather, 7-1-9
Minimum Fuel, 5-5-6
Runway Friction, 4-3-8
Traffic, 5-5-4
Aerobatic Flight, 8-1-7
Aeronautical
Charts, 9-1-1
Publications, 9-1-1
Aeronautical Light Beacons, 2-2-1
AHRS. See Attitude Heading Reference System
Air Ambulance Flights, 4-2-4
Air Defense Identification Zone, Land-Based, 5-6-1
Air Defense Identification Zones, 5-6-1, 5-6-7
Air Route Surveillance Radar, 4-5-7
Air Route Traffic Control Centers, 4-1-1
Air Traffic Control
Aircraft Separation, 4-4-1
Clearances, 4-4-1
Pilot Services, 4-1-1
Air Route Traffic Control Centers, 4-1-1
Airport Reservations, 4-1-21
Approach Control Service, Arriving VFR
Aircraft, 4-1-2
Automatic Terminal Information Service, 4-1-7
Communications, Release of IFR Aircraft, Airports
without Operating Control Tower, 4-1-1
Control Towers, 4-1-1
Flight Service Stations, 4-1-1
Ground Vehicle Operations, 4-1-6
Hazardous Area Reporting Service, 4-1-18
IFR Approaches, 4-1-6
Operation Raincheck, 4-1-2
Operation Take-off, 4-1-2
Radar Assistance to VFR Aircraft, 4-1-11
Radar Traffic Information Service, 4-1-8
Recording and Monitoring, 4-1-1
Safety Alert, 4-1-10
Terminal Radar Services for VFR Aircraft, 4-1-12
Tower En Route Control, 4-1-14
Traffic Advisory Practices, Airports Without
Operating Control Towers, 4-1-2
Transponder Operation, 4-1-15
Unicom, Use for ATC Purposes, 4-1-7
Unicom/Multicom, 4-1-6
Air Traffic Control Radar Beacon System, 4-1-15,
4-5-2
Aircraft
Arresting Devices, 2-3-30
Call Signs, 4-2-3
Lights, Use in Airport Operations, 4-3-19
Unmanned, 7-5-2
VFR, Emergency Radar Service, 6-2-1
Aircraft Conflict Alert, 4-1-11
Airport
Aids, Marking, 2-3-1
Holding Position, 2-3-12
Pavement, 2-3-1
Holding Position, 2-3-1
Other, 2-3-1
Runway, 2-3-1
Taxiway, 2-3-1
Airport Advisory/Information Services, 3-5-1
Lighting Aids, 2-1-1
Local Airport Advisory (LAA), 4-1-3
Operations, 4-3-1
Communications, 4-3-12
Exiting the Runway, After Landing, 4-3-17
Flight Check Aircraft, In Terminal Areas, 4-3-20
Flight Inspection, 4-3-20
Gate Holding, Departure Delays, 4-3-13
Intersection Takeoffs, 4-3-8
Low Approach, 4-3-11
Low Level Wind Shear/Microburst Detection
Systems, 4-3-7
Option Approach, 4-3-19
Signals, Hand, 4-3-20
Taxi During Low Visibility, 4-3-16
Traffic Control Light Signals, 4-3-11
Traffic Patterns, 4-3-1, 4-3-2
Use of Aircraft Lights, 4-3-19
Use of Runways, 4-3-6
VFR Flights in Terminal Areas, 4-3-13
VFR Helicopter at Controlled Airports, 4-3-13
7/31/08 AIM
Index I-2
With Operating Control Tower, 4-3-1
Without Operating Control Tower, 4-3-5
Remote Airport Advisory (RAA), 3-5-1, 4-1-4
Remote Airport Information Service (RAIS), 3-5-1,
4-1-4
Signs, 2-3-1, 2-3-19
Destination, 2-3-28
Direction, 2-3-25
Information, 2-3-29
Location, 2-3-23
Mandatory Instruction, 2-3-20
Runway Distance Remaining, 2-3-29
Airport Reservations, 4-1-21
Airport Surface Detection Equipment -Model X
(ASDE-X), 4-5-7
Airport Surveillance Radar, 4-5-7
Airspace, 3-1-1
Basic VFR Weather Minimums, 3-1-1
Class D, 3-2-8
Class E, 3-2-9
Class G, 3-3-1
Controlled, 3-2-1
Advisories, Traffic, 3-2-1
Alerts, Safety, 3-2-1
Class A, 3-2-2
Class B, 3-2-2
Class C, 3-2-4
IFR Requirements, 3-2-1
IFR Separation, 3-2-1
Parachute Jumps, 3-2-2
Ultralight Vehicles, 3-2-2
Unmanned Free Balloons, 3-2-2
VFR Requirements, 3-2-1
Flight Levels, 3-1-2
General Dimensions, Segments, 3-1-1
Military Training Routes, 3-5-1
Other Areas, 3-5-1
Parachute Jumping, 3-5-5
Special Use, 3-4-1
Temporary Flight Restrictions, 3-5-2
Terminal Radar Service Areas, 3-5-9
VFR Cruising Altitudes, 3-1-2
VFR Routes, Published, 3-5-5
Class B Airspace, VFR Transition Routes, 3-5-7
VFR Corridors, 3-5-7
VFR Flyways, 3-5-5
Airway, 5-3-5
Airways, Course Changes, 5-3-7
Alcohol, 8-1-1
Alert, Safety, 4-1-10, 5-5-3
Alert Areas, 3-4-2
Alignment of Elements Approach Slope Indicator,
2-1-5
Alphabet, Phonetic, 4-2-5
ALS. See Approach Light Systems
Altimeter
Density Altitude, 7-5-4
Errors, 7-2-3
Setting, 7-2-1
High Barometric Pressure, 7-2-4
Low Barometric Pressure, 7-2-4
Altitude
Automatic Reporting, 4-1-15
Effects, 8-1-3
Hypoxia, 8-1-3
High Altitude Destinations, 5-1-16
Mandatory, 5-4-6
Maximum, 5-4-6
Minimum, 5-4-6
Ambulance, Air, 4-2-4
Amended Clearances, 4-4-2
Approach
Advance Information, Instrument Approach, 5-4-4
Approach Control, 5-4-3
Clearance, 5-4-23
Contact, 5-4-51, 5-5-2
Direction Finding, Emergency, 6-2-1
Instrument, 5-5-2
Instrument Approach Procedure, Charts, 5-4-4
Instrument Approach Procedures, 5-4-24
Low, 4-3-11
Minimums, 5-4-45
Missed, 5-4-47, 5-5-2
No-Gyro, 5-4-31
Option, 4-3-19
Overhead Approach Maneuver, 5-4-51
Precision, 5-4-30
Surveillance, 5-4-30
Visual, 5-4-49, 5-5-5
Approach Control Service, VFR Arriving Aircraft,
4-1-2
Approach Light Systems, 2-1-1
Approaches
IFR, 4-1-6
Parallel Runways, ILS/MLS, 5-4-32
Radar, 5-4-30
Timed, 5-4-27
7/31/08 AIM
Index I-3
Area Navigation (RNAV), 1-2-1, 5-1-13, 5-3-6,
5-5-7
Area Navigation (RNAV) Routes, 5-3-6
Area Navigation (RNAV) Standard Terminal Arrival
(STAR), 5-4-1
ARFF (Aircraft Rescue and Fire Fighting) Emergency
Hand Signals, 6-5-1
ARFF (Aircraft Rescue and Fire Fighting) Radio Call
Sign, 6-5-1
Arresting Devices, Aircraft, 2-3-30
ARSR. See Air Route Surveillance Radar
ARTCC. See Air Route Traffic Control Centers
Ash, Volcanic, 7-5-7
ASOS. See Automated Surface Observing System
ASR. See Airport Surveillance Radar; Surveillance
Approach
ATCRBS. See Air Traffic Control Radar Beacon
System
ATCT. See Control Towers
ATIS. See Automatic Terminal Information Service
Attitude Heading Reference System (AHRS), 1-1-24
Authority, Statutory, 1-1-1
Automated Surface Observing System (ASOS), 4-3-24,
7-1-26
Automated Weather Observing System (AWOS),
4-3-24, 7-1-24
Automated Weather Sensor System (AWSS), 7-1-26
Automatic Altitude Reporting, 4-1-15
Automatic Dependent Surveillance-Broadcast, 4-4-11
Automatic Flight Information Service (AFIS) -
Alaska FSSs Only.
See AFIS
Automatic Terminal Information Service, 4-1-7
AWOS. See Automated Weather Observing System
B
Balloons, Unmanned, 7-5-2
Free, 3-2-2
Beacon
Aeronautical Light, 2-2-1
Code, 2-2-1
Marker, 1-1-9
Nondirectional Radio, 1-1-1
Beacons, Airport/Heliport, 2-1-8
Bird
Bird Strike
Reduction, 7-4-1
Reporting, 7-4-1
Hazards, 7-4-1
Migratory, 7-4-1
Bird/Other Wildlife Strike Reporting, Form.
See Appendix 1
Block Island Reporting Service, 4-1-19
Braking Action Advisories, 4-3-7
Braking Action Reports, 4-3-7
Briefing, Preflight, 7-1-6
C
Call Signs
Aircraft, 4-2-3
Ground Station, 4-2-4
Cape Code Radar Overwater Flight Following, 4-1-19
Carbon Monoxide Poisoning, 8-1-5
CAT. See Clear Air Turbulence
CDR. See Coded Depature Route
Changeover Points, 5-3-8
Charted Visual Flight Procedures, 5-4-50
Charts, Aeronautical, 9-1-1
Class A Airspace, 3-2-2
Definition, 3-2-2
Operating Rules, 3-2-2
Pilot/Equipment Requirements, 3-2-2
Class B Airspace, 3-2-2
ATC Clearances, 3-2-3
Definition, 3-2-2
Flight Procedures, 3-2-3
Mode C Veil, 3-2-3
Operating Rules, 3-2-2
Pilot/Equipment Requirements, VFR Operations,
3-2-2
Proximity Operations, 3-2-4
Separation, 3-2-3
VFR Transition Routes, 3-5-7
Class C Airspace, 3-2-4
Air Traffic Services, 3-2-5
Aircraft Separation, 3-2-5
Definition, 3-2-4
7/31/08 AIM
Index I-4
Operating Rules, 3-2-4
Outer Area, 3-2-5
Pilot/Equipment Requirements, 3-2-4
Secondary Airports, 3-2-6
Class D Airspace, 3-2-8
Definition, 3-2-8
Operating Rules, 3-2-8
Pilot/Equipment Requirements, 3-2-8
Separation for VFR Aircraft, 3-2-9
Class E Airspace, 3-2-9
Definition, 3-2-9
Operating Rules, 3-2-9
Pilot/Equipment Requirements, 3-2-9
Separation for VFR Aircraft, 3-2-9
Types, 3-2-9
Vertical Limits, 3-2-9
Class G Airspace, 3-3-1
IFR Requirements, 3-3-1
VFR Requirements, 3-3-1
Clear Air Turbulence, 7-1-45
Clearance
Abbreviated IFR Departure, 5-2-2
Adherence, 4-4-5
Air Traffic, 5-5-1
Air Traffic Control, 4-4-1
Amended, 4-4-2
Approach, 5-4-23
IFR, VFR-on-Top, 4-4-4
IFR Flights, 4-4-5
Issuance, Pilot Responsibility, 4-4-4
Items, 4-4-1
Altitude Data, 4-4-2
Clearance Limit, 4-4-1
Departure Procedure, 4-4-1
Holding Instructions, 4-4-2
Route of Flight, 4-4-1
Pre-Taxi, 5-2-1
Prefix, 4-4-1
Taxi, 5-2-1
VFR Flights, 4-4-5
Void Times, 5-2-4
Clearances, Special VFR Clearances, 4-4-3
Clearing Procedures, Visual, 4-4-10
CNF. See Computer Navigation Fix
Coded Depature Route, 4-4-3
Collision, Avoidance, Judgment, 8-1-8
Communication, Radio
Contact, Reestablishing, 6-4-2
Two-way Failure, 6-4-1
IFR Conditions, 6-4-1
Transponder Usage, 6-4-2
VFR Conditions, 6-4-1
Communications
ARTCC, 5-3-1
Additional Reports, 5-3-4
Position Reporting, 5-3-3
Distress, 6-3-1
Radio, 4-2-1
Phonetic Alphabet, 4-2-5
Release, 4-1-1
Urgency, 6-3-1
Computer Navigation Fix (CNF), 1-1-33
Conflict Alert, Aircraft, 4-1-11
Contact Approach, 5-4-51
Contact Procedures, 4-2-1
Initial Contact, 4-2-1
Control of Lighting Systems, 2-1-6
Control Towers, 4-1-1
Controlled Firing Areas, 3-4-2
Controller, Responsibility, 5-3-8, 5-4-50, 5-5-1
COP. See Changeover Points
CORONA, 7-5-9
Course Lights, 2-2-1
CVFP. See Charted Visual Flight Procedures
D
Decompression Sickness, 8-1-4
Density Altitude, Effects, 7-5-4
Departure, Restrictions, 5-2-4
Departure Control, 5-2-5
Departures, Instrument, 5-5-6
DF. See Direction Finder
Direct User Access Terminal System, 7-1-3
Direction Finder, VHF, 1-1-24
Discrete Emergency Frequency, 6-5-1
Distance Measuring Equipment, 1-1-3, 1-1-9, 5-3-12
Distress, 6-3-1
Ditching Procedures, 6-3-3
DME. See Distance Measuring Equipment
7/31/08 AIM
Index I-5
Doppler Radar, 1-1-24
DUATS. See Direct User Access System
E
Ear Block, 8-1-3
EFAS. See En Route Flight Advisory Service
ELT. See Emergency Locator Transmitters
Emergency, 6-1-1
Air Piracy, 6-3-6
Airborne Aircraft Inspection, 7-5-8
Aircraft, Overdue, 6-2-5
Body Signals, 6-2-6
Direction Finding Instrument Approach, 6-2-1
Ditching Procedures, 6-3-3
Explosives Detection, FAA K-9 Team Program,
6-2-4
Fuel Dumping, 6-3-7
Inflight Monitoring and Reporting, 6-2-4
Intercept and Escort, 6-2-2
Locator Transmitters, 6-2-2
Obtaining Assistance, 6-3-2
Pilot Authority, 6-1-1
Pilot Responsibility, 6-1-1
Request Assistance Immediately, 6-1-1
Search and Rescue, 6-2-5
Services, 6-2-1
Radar Service for VFR Aircraft in Difficulty,
6-2-1
Survival Equipment, 6-2-6
Transponder Operation, 6-2-1
VFR Search and Rescue Protection, 6-2-6
Emergency Locator Transmitter, 6-2-2
En Route Flight Advisory Service, 7-1-8
Escort, 6-2-2
Explosives, FAA K-9 Detection Team Program, 6-2-4
F
Final Guard, 3-5-1
Fitness, Flight
Alcohol, 8-1-1
Emotion, 8-1-2
Fatigue, 8-1-2
Hypoxia, 8-1-3
Stress, 8-1-2
Flight
Aerobatic, 8-1-7
Fitness, 8-1-1
Illusions, 8-1-5
Over National Forests, 7-4-1
Over National Parks, 7-4-1
Over National Refuges, 7-4-1
Safety, Meteorology, 7-1-1
Vision, 8-1-6
Flight Check Aircraft, 4-3-20
Flight Information Services, 7-1-21
Flight Inspections Aircraft, 4-3-20
Flight Management System, 1-2-3, 5-1-11
Flight Management System Procedures, 5-4-1
Flight Plan
Change, 5-1-18
Proposed Departure Time, 5-1-18
Closing
DVFR, 5-1-19
VFR, 5-1-19
Composite, VFR/IFR, 5-1-9
DVFR Flights, 5-1-9
Explanation of IFR, 5-1-14
Explanation of VFR, 5-1-8
Form 7233-1, 5-1-8, 5-1-15
IFR, Canceling, 5-1-19
IFR Flights, 5-1-10
VFR Flights, 5-1-7
Flight Restrictions, Temporary, 3-5-2
Flight Service Stations, 4-1-1
Flights, Outside the United States, 5-1-17
Flying, Mountain, 7-5-3
FMS. See Flight Management System
FMSP. See Flight Management System Procedures
Forms
Bird Strike Incident/Ingestion Report, Appendix 1-1
Volcanic Activity Reporting Form, Appendix 2-1
Frequency, Instrument Landing System, 1-1-10
FSS. See Flight Service Stations
Fuel Dumping, 6-3-7
G
Gate Holding, 4-3-13
GBAS. See Ground Based Augmentation System
7/31/08 AIM
Index I-6
Glideslope
Runway Centerline Lighting System (RCLS), 2-1-5
Visual Indicators, 2-1-2
Global Navigation Satellite System, 1-1-40, 5-1-11
Global Positioning System, 1-1-24
Database, 1-1-31
Equipment, 1-1-31
GPS Approach Procedures, 1-1-31
GLS. See GNSS Landing System
GNSS. See Global Navigation Satellite System
GNSS Landing System (GLS), 1-1-40
GPS. See Global Positioning System
GPS Approach Procedures, 1-1-31
Ground Based Augmentation System (GBAS), 1-1-41
Ground Station, Call Signs, 4-2-4
Ground Vehicle Operations, 4-1-6
Gulf of Mexico Grid System, 10-1-6
H
Half-Way Signs, 7-5-5
Hand Signals, 4-3-20
Hazard
Antenna Tower, 7-5-1
Bird, 7-4-1
Flight
Obstructions to Flight, 7-5-1
Potential, 7-5-1
VFR in Congested Areas, 7-5-1
Ground Icing Conditions, 7-5-12
Mountain Flying, 7-5-3
Overhead Wires, 7-5-2
Unmanned Balloons, 7-5-2
Volcanic Ash, 7-5-7
Hazardous Area Reporting Service, 4-1-18
HDTA. See High Density Traffic Airports
Helicopter
IFR Operations, 10-1-1
Landing Area Markings, 2-3-19
VFR Operations at Controlled Airports, 4-3-13
Special Operations, 10-2-1
Wake Turbulence, 7-3-6
High Density Traffic Airports, 4-1-21
Hold, For Release, 5-2-4
Holding, 5-3-8
Holding Position Markings, 2-3-1, 2-3-12
for Instrument Landing Systems, 2-3-12
for Taxiway/Taxiway Intersections, 2-3-12
Holding Position Signs, Surface Painted, 2-3-12
Hypoxia, 8-1-3
I
Icing Terms, 7-1-42
IFR, 4-4-4
Operations, To High Altitude Destinations, 5-1-16
Procedures, Use When Operating VFR, 5-1-2
IFR
Approaches, 4-1-6
Military Training Routes, 3-5-2
Separation Standards, 4-4-7
ILS. See Instrument Landing System
In-Runway Lighting, 2-1-5
Taxiway Centerline Lead-off Lights, 2-1-6
Taxiway Centerline Lead-On Lights, 2-1-6
Touchdown Zone Lighting, 2-1-6
Incident, Aircraft, Reporting, 7-6-1
Inertial Navigation System, 1-1-24
Inertial Reference Unit (IRU), 1-1-24, 5-1-11
Initial Contact, 4-2-1
INS. See Internal Navigation System
Instrument Departure Procedures (DP), 5-2-5
Instrument Landing System, 1-1-7
Category, 1-1-10
Compass Locator, 1-1-10
Course, Distortion, 1-1-11
Distance Measuring Equipment, 1-1-9
Frequency, 1-1-10
Glide Path, 1-1-8
Glide Slope, 1-1-8
Critical Area, 1-1-11
Holding Position Markings, 2-3-12
Inoperative Components, 1-1-10
Localizer, 1-1-7
Critical Area, 1-1-11
Locators, Compass, 1-1-7
Marker Beacon, 1-1-9
Minimums, 1-1-10
Instrument Meteorological Conditions (IMC), 5-2-5
Integrated Terminal Weather System, 4-3-7
7/31/08 AIM
Index I-7
Intercept, 6-2-2
Interception
Procedures, 5-6-2
Signals, 5-6-5
Interchange Aircraft, 4-2-4
Intersection Takeoffs, 4-3-8
IR. See IFR Military Training Routes
IRU. See Inertial Reference Unit
ITWS. See Integrated Terminal Weather System
K
K-9 Explosives Detection Team, 6-2-4
L
LAHSO. See Land and Hold Short Operations
Land and Hold Short Lights, 2-1-6
Land and Hold Short Operations (LAHSO), 4-3-9
Landing
Minimums, 5-4-45
Priority, 5-4-51
Laser Beam Exposure Questionnaire, Appendix 3-1
Laser Operations, 7-5-10
Law Enforcement Operations
Civil, 5-6-4
Military, 5-6-4
LDA. See Localizer-Type Directional Aid
Leased Aircraft, 4-2-4
Lifeguard, 4-2-4
Light Signals, Traffic Control, 4-3-11
Lighting
Aeronautical Light Beacons, 2-2-1
Aids
Airport, 2-1-1
Approach Light Systems, 2-1-1
Control of Lighting Systems, 2-1-6
In-Runway Lighting, 2-1-5
Pilot Control of Airport Lighting, 2-1-6
Runway End Identifier Lights, 2-1-5
Taxiway Lights, 2-1-9
Airport/Heliport Beacons, 2-1-8
Airport, Radio Control, 4-1-6
Code Beacon, 2-2-1
Course, 2-2-1
Navigation, 2-2-1
Obstruction, 2-2-1
LLWAS. See Low Level Wind Shear Alert System
Local Airport Advisory (LAA), 3-5-1, 4-1-3
Local Flow Traffic Management Program, 5-4-2
Localizer Performance with Vertical Guidance, 1-1-37
Localizer-Type Directional Aid, 1-1-8
Locator, Compass, 1-1-10
Long Island Sound Reporting Service, 4-1-18
Long Range Navigation, 1-1-16
Chain, 1-1-17
Receiver, 1-1-22
LORAN. See Long Range Navigation
Low Approach, 4-3-11
Low Level Wind Shear Alert System (LLWAS), 4-3-7,
7-1-49
Low Level Wind Shear/Microburst Detection Systems,
4-3-7
LPV. See Localizer Perfomance with Vertical Guidance
M
MAYDAY, 6-3-1
Medical
Carbon Monoxide Poisoning, 8-1-5
Decompression Sickness, 8-1-4
Facts, Pilots, 8-1-1
Flight, Ear Block, 8-1-3
Illness, 8-1-1
Medication, 8-1-1
Sinus Block, 8-1-4
Meteorology, 7-1-1
ATC InFlight Weather Avoidance, 7-1-35
Automated Surface Observing System, 7-1-26
Categorical Outlooks, 7-1-19
Clear Air Turbulence, 7-1-45
Cloud Heights, Reporting, 7-1-38
Direct User Access Terminal System, 7-1-3
Drizzle, Intensity, 7-1-39
En Route Flight Advisory Service, 7-1-8
FAA Weather Services, 7-1-1
ICAO, Weather Formats, 7-1-60
Icing, Airframe, 7-1-41
Inflight Aviation Weather Advisories, 7-1-9
Inflight Weather Broadcasts, 7-1-20
Microbursts, 7-1-45
7/31/08 AIM
Index I-8
National Weather Service, Aviation Products, 7-1-1
Pilot Weather Reports, 7-1-39
Precipitation, Intensity, 7-1-39
Preflight Briefing, 7-1-6
Runway Visual Range, 7-1-37
Telephone Information Briefing Service, 7-1-19
Thunderstorms, 7-1-55
Flying, 7-1-56
Transcribed Weather Broadcast, 7-1-19
Turbulence, 7-1-44
Visibility, Reporting, 7-1-39
Weather, Radar Services, 7-1-31
Weather Observing Programs, 7-1-24
Wind Shear, 7-1-45
Microwave Landing System, 1-1-13
Approach Azimuth Guidance, 1-1-13
Data Communications, 1-1-14
Elevation Guidance, 1-1-14
Operational Flexibility, 1-1-15
Range Guidance, 1-1-14
Military Operations Areas, 3-4-2
Military Training Routes, 3-5-1
IFR, 3-5-2
VFR, 3-5-2
Minimum, Fuel Advisory, 5-5-6
Minimum Safe Altitudes, 5-4-6
Minimum Vectoring Altitudes, 5-4-17
Minimums
Approach, 5-4-45
Instrument Landing Systems, 1-1-10
Landing, 5-4-45
Missed Approach, 5-4-47
MLS. See Microwave Landing System
MOA. See Military Operations Areas
Mode C, 4-1-15
Mountain Flying, 7-5-3
Mountain Wave, 7-5-4
Mountainous Areas, 5-6-7
MSA. See Minimum Safe Altitudes
Multicom, 4-1-6
MVA. See Minimum Vectoring Altitudes
N
National Forests, 7-4-1
National Geospatial-Intelligence Agency (NGA),
5-4-6
National Parks, 7-4-1
National Refuges, 7-4-1
National Security Areas, 3-5-9
National Weather Service, Aviation Products, 7-1-1
NAVAID
Identifier Removal During Maintenance, 1-1-15
Maintenance, 1-1-15
Performance, User Report, 1-1-16
Service Volumes, 1-1-4
with Voice, 1-1-16
Navigation, Aids, 1-1-1
Nondirectional Radio Beacon, 1-1-1
Radio, VHF Omni-directional Range, 1-1-1
Navigation Reference System (NRS), 5-1-14
Navigational
Aids, Radio
Distance Measuring Equipment, 1-1-3
Doppler Radar, 1-1-24
Identifier Removal During Maintenance, 1-1-15
Instrument Landing System, 1-1-7
Localizer-Type Directional Aid, 1-1-8
Long Range Navigation, 1-1-16
Microwave Landing System, 1-1-13
Navaid Service Volumes, 1-1-4
NAVAIDs with Voice, 1-1-16
Performance, User Report, 1-1-16
Simplified Directional Facility, 1-1-11
Tactical Air Navigation, 1-1-3
VHF Direction Finder, 1-1-24
VHF Omni-directional Range/Tactical Air
Navigation, 1-1-3
Inertial Navigation System, 1-1-24
NDB. See Nondirectional Radio Beacon
Near Midair Collision, 7-6-2
NGA. See National Geospatial-Intelligence Agency
NMAC. See Near Midair Collision
Nondirectional Radio Beacon, 1-1-1
Nonmovement Area Boundary Markings, 2-3-18
NOTAM. See Notice to Airmen
Notice to Airmen, 5-1-2
FDC NOTAM, 5-1-3
7/31/08 AIM
Index I-9
NOTAM Contractions, 5-1-4
NOTAM D, 5-1-3
NOTAM L, 5-1-3
Notice to Airmen System, 5-1-2
O
Obstacle Departure Procedures, 5-2-5
Obstruction Alert, 4-1-10
Operation Raincheck, 4-1-2
Operation Take-off, 4-1-2
Operational Information System (OIS), 5-1-9
Option Approach, 4-3-19
P
P-static, 7-5-9
PAN-PAN, 6-3-1
PAPI. See Precision Approach Path Indicator
PAR. See Precision Approach; Precision Approach
Radar
Parachute Jumps, 3-2-2, 3-5-5
Phonetic Alphabet, 4-2-5
Pilot
Authority, 6-1-1
Responsibility, 4-1-14, 4-4-1, 4-4-4, 5-4-50,
5-5-1, 6-1-1, 7-3-6
Pilot Control of Airport Lighting, 2-1-6
Pilot Visits to Air Traffic Facilities, 4-1-1
Pilot Weather Reports, 7-1-39
Piracy, Air, Emergency, 6-3-6
PIREPs. See Pilot Weather Reports
Position Reporting, 5-3-3
Pre-departure Clearance Procedures, 5-2-1
Precipitation Static, 7-5-9
Precision Approach, 5-4-30
Precision Approach Path Indicator, 2-1-3
Precision Approach Radar, 4-5-7
Precision Approach Systems, 1-1-40
Preflight, Preparation, 5-1-1
Priority, Landing, 5-4-51
Procedure Turn, 5-4-26
Limitations, 5-4-27
Procedures
Arrival, 5-4-1
En Route, 5-3-1
Instrument Approach, 5-4-24
Interception, 5-6-2
Prohibited Areas, 3-4-1
Publications, Aeronautical, 9-1-1
Pulsating Visual Approach Slope Indicator, 2-1-5
R
Radar
Air Traffic Control Radar Beacon System, 4-5-2
Airport Route Surveillance Radar, 4-5-7
Airport Surveillance Radar, 4-5-7
Approach Control, 5-4-3
Approaches, 5-4-30
Capabilities, 4-5-1
Doppler, 1-1-24
Limitations, 4-5-1
Monitoring of Instrument Approaches, 5-4-31
Precision Approach, 4-5-7
Precision Approach Radar, 4-5-7
Surveillance, 4-5-7
Vector, 5-5-3
Radar Assistance to VFR Aircraft, 4-1-11
Radar Beacon, Phraseology, 4-1-17
Radar Sequencing and Separation, VFR Aircraft,
TRSA, 4-1-13
Radar Traffic Information Service, 4-1-8
Radio, Communications, 4-2-1
Altitudes, 4-2-6
Contact Procedures, 4-2-1
Directions, 4-2-6
Inoperative Transmitter, 4-2-7
Phonetic Alphabet, 4-2-5
Receiver Inoperative, 4-2-7
Speeds, 4-2-6
Student Pilots, 4-2-4
Technique, 4-2-1
Time, 4-2-6
Transmitter and Receiver Inoperative, 4-2-7
VFR Flights, 4-2-8
RCLS. See Runway Centerline Lighting
Receiver, VOR, Check, 1-1-2
7/31/08 AIM
Index I-10
REIL. See Runway End Identifier Lights
Release Time, 5-2-4
Remote Airport Advisory (RAA), 3-5-1, 4-1-4
Remote Airport Information Service (RAIS), 3-5-1,
4-1-4
Required Navigation Performance (RNP), 1-2-1,
5-4-21
Required Navigation Performance (RNP) Operations,
5-1-19, 5-5-7
Rescue Coordination Center
Air Force, 6-2-5
Alaska, 6-2-5
Coast Guard, 6-2-5
Joint Rescue, Hawaii, 6-2-5
Reservations, Airport, 4-1-21
Responsibility
Controller, 5-3-8, 5-4-50, 5-5-1
Pilot, 4-1-14, 4-4-1, 4-4-4, 5-4-50, 5-5-1, 6-1-1,
7-3-6
Restricted Areas, 3-4-1
Restrictions
Departure, 5-2-4
Flight, Temporary, 3-5-2
RNAV. See Area Navigation
RNP. See Required Navigation Performance
Route
Coded Departure Route, 4-4-3
Course Changes, 5-3-7
Route System, 5-3-5
Runway
Aiming Point Markings, 2-3-2
Centerline Markings, 2-3-2
Closed
Lighting, 2-3-18
Marking, 2-3-18
Demarcation Bar, 2-3-4
Designators, 2-3-2
Holding Position Markings, 2-3-12
Markings, 2-3-1
Separation, 4-4-9
Shoulder Markings, 2-3-3
Side Stripe Markings, 2-3-3
Signs, Distance Remaining, 2-3-29
Threshold Bar, 2-3-4
Threshold Markings, 2-3-3
Touchdown Zone Markers, 2-3-2
Runway Centerline Lighting System (RCLS), 2-1-5
Runway Edge Light Systems, 2-1-5
Runway End Identifier Lights, 2-1-5
Runway Friction Advisories, 4-3-8
Runway Friction Reports, 4-3-8
Runway Visual Range, 7-1-37
Runways, Use, 4-3-6
RVR. See Runway Visual Range
S
Safety
Alert, 5-5-3
Alerts, 3-2-1
Aircraft Conflict, 3-2-1
Mode C Intruder, 3-2-1
Terrain/Obstruction, 3-2-1
Aviation, Reporting, 7-6-1
Seaplane, 7-5-6
Safety Alert, 4-1-10
Aircraft Conflict Alert, 4-1-11
Obstruction Alert, 4-1-10
Terrain Alert, 4-1-10
SAR. See Search and Rescue
SCAT-I DGPS. See Special Category I Differential
GPS
SCATANA. See Security Control of Air Traffic and Air
Navigation Aids
Scuba Diving, Decompression Sickness, 8-1-4
SDF. See Simplified Directional Facility
Seaplane, Safety, 7-5-6
Search and Rescue, 6-2-2, 6-2-5
Security, National, 5-6-1
Security Control of Air Traffic and Air Navigation
Aids, 5-6-2
See and Avoid, 5-5-4
Separation
IFR, Standards, 4-4-7
Runway, 4-4-9
Visual, 4-4-9, 5-5-5
Wake Turbulence, 7-3-7
Side-Step Maneuver, 5-4-45
7/31/08 AIM
Index I-11
Signs
Airport, 2-3-1
Half-Way, 7-5-5
Simplified Directional Facility, 1-1-11
Sinus Block, 8-1-4
Special Category I Differential GPS (SCAT-I DGPS),
1-1-41
Special Instrument Approach Procedures, 1-1-41,
5-4-26
Special Traffic Management Programs, 4-1-21
Special Use Airspace, 3-4-1
Alert Areas, 3-4-2
Controlled Firing Areas, 3-4-2
Military Operations Areas, 3-4-2
Prohibited Areas, 3-4-1
Restricted Areas, 3-4-1
Warning Areas, 3-4-1
Special VFR Clearances, 4-4-3
Speed, Adjustments, 4-4-7, 5-5-4
Standard Instrument Departures, 5-2-5
Standard Terminal Arrival, 5-4-1
STAR. See Standard Terminal Arrival
Supplemental Weather Service Locations, 4-1-1
Surface Painted Holding Position Signs, 2-3-12
Surveillance Approach, 5-4-30
Surveillance Radar, 4-5-7
Surveillance Systems, 4-5-1
SWSL. See Supplemental Weather Service Locations
T
TACAN. See Tactical Air Navigation
Tactical Air Navigation, 1-1-3
Takeoffs, Intersection, 4-3-8
Taxi
Clearance, 5-2-1
During Low Visibility, 4-3-16
Taxi Into Position And Hold, Taxi, 5-2-1
Taxiway
Centerline Markings, 2-3-7
Closed
Lighting, 2-3-18
Marking, 2-3-18
Edge Markings, 2-3-7
Geographic Position Markings, 2-3-10
Holding Position Markings, 2-3-12
Markings, 2-3-1, 2-3-7
Shoulder Markings, 2-3-7
Surface Painted Direction Signs, 2-3-10
Surface Painted Location Signs, 2-3-10
Taxiway Centerline Lead-Off Lights, 2-1-6
Taxiway Lights, 2-1-9
Centerline, 2-1-9
Clearance Bar, 2-1-9
Edge, 2-1-9
Runway Guard, 2-1-9
Stop Bar, 2-1-9
TCAS. See Traffic Alert and Collision Avoidance
System
TDWR. See Terminal Doppler Weather Radar
TDZL. See Touchdown Zone Lights
TEC. See Tower En Route Control
Telephone Information Briefing Service, 7-1-19
Temporary Flight Restrictions, 3-5-2
Terminal Arrival Area (TAA), 5-4-7
Terminal Doppler Weather Radar (TDWR), 4-3-7,
7-1-50
Terminal Radar Service Areas, 3-5-9
Terminal Radar Services for VFR Aircraft, 4-1-12
Terminal Weather Information For Pilots System
(TWIP), 7-1-55
Terrain Alert, 4-1-10
TIBS. See Telephone Information Briefing Service
Time
Clearance Void, 5-2-4
Release, 5-2-4
TIPH. See Taxi Into Position And Hold
TIS-B. See Traffic Information Service-Broadcast
TLS. See Transponder Landing System
Touchdown Zone Lights (TDZL), 2-1-6
Tower, Antenna, 7-5-1
Tower En Route Control, 4-1-14
Traffic
Advisories, 5-5-4
Local Flow Traffic Management Program, 5-4-2
Traffic Advisory Practices, Airports Without Operating
Control Towers, 4-1-2
7/31/08 AIM
Index I-12
Traffic Alert and Collision Avoidance System, 4-4-10
Traffic Control Light Signals, 4-3-11
Traffic Information Service (TIS), 4-4-11, 4-5-8
Traffic Information Service-Broadcast, 4-4-11
Traffic Patterns, 4-3-2
Transcribed Weather Broadcast, 7-1-19
Transponder Landing System (TLS), 1-1-41
Transponder Operation, 4-1-15
Automatic Altitude Reporting, 4-1-15
Code Changes, 4-1-16
Emergency, 6-2-1
Ident Feature, 4-1-16
Mode C, 4-1-15
Under Visual Flight Rules, 4-1-17
VFR, 4-1-17
Tri-Color Visual Approach Slope Indicator, 2-1-4
TRSA. See Terminal Radar Service Areas
Turbulence, Wake, 7-3-1
Air Traffic Separation, 7-3-7
Helicopters, 7-3-6
Pilot Responsibility, 7-3-6
Vortex Behavior, 7-3-2
Vortex Generation, 7-3-1
Vortex Strength, 7-3-1
TWEB. See Transcribed Weather Broadcast
TWIP. See Terminal Weather Information For Pilots
System
U
Ultralight Vehicles, 3-2-2
Unicom, 4-1-6
Unidentified Flying Object (UFO) Reports, 7-6-3
Unmanned Aircraft, 7-5-2
Urgency, 6-3-1
V
VASI. See Visual Approach Slope Indicator
VCOA. See Visual Climb Over the Airport
VDP. See Visual Descent Points
Vector, Radar, 5-5-3
Vehicle Roadway Markings, 2-3-16
Vertical Navigation, 5-1-11
VFR Corridors, 3-5-7
VFR Flights in Terminal Areas, 4-3-13
VFR Flyways, 3-5-5
VFR Military Training Routes, 3-5-2
VFR Transition Routes, 3-5-7
VFR-on-Top, 5-5-6
VHF, Direction Finder, 1-1-24
VHF Omni-directional Range, 1-1-1
VHF Omni-directional Range/Tactical Air Navigation,
1-1-3
Visual
Approach, 5-4-49, 5-5-5
Clearing Procedures, 4-4-10
Glideslope Indicators, 2-1-2
Separation, 4-4-9, 5-5-5
Visual Approach Slope Indicator, 2-1-2
Visual Climb Over the Airport (VCOA), 5-2-7
Visual Descent Points, 5-4-17
Visual Meteorological Conditions (VMC), 5-2-5
VNAV. See Vertical Navigation
Void Times, Clearance, 5-2-4
Volcanic, Ash, 7-5-7
Volcanic Activity Reporting, Forms. See Appendix 2
VOR
See also VHF Omni-directional Range
Receiver Check, 1-1-2
VOR Receiver Checkpoint Markings, 2-3-16
VORTAC. See VHF Omni-directional Range/Tactical
Air Navigation
VR. See VFR Military Training Routes
W
Waivers, 4-1-23
Wake, Turbulence, 7-3-1
Warning Areas, 3-4-1
Weather
Deviations in Oceanic Controlled Airspace, 7-1-36
ICAO, Weather Formats, 7-1-60
Weather System Processor (WSP), 4-1-23, 4-3-7,
7-1-51
WSP. See Weather System Processor
U.S. Department
Of Transportation
Federal Aviation
Administration
