T
TACAN-
(See TACTICAL AIR
NAVIGATION.)
TACAN-ONLY AIRCRAFT- An
aircraft, normally military, possessing TACAN with DME but no VOR navigational
system capability. Clearances must specify TACAN or VORTAC fixes and approaches.
TACTICAL AIR NAVIGATION-
An ultra-high frequency electronic rho-theta air navigation aid which provides
suitably equipped aircraft a continuous indication of bearing and distance to
the TACAN station.
(See VORTAC.)
(Refer to AIM.)
TAILWIND- Any wind more
than 90 degrees to the longitudinal axis of the runway. The magnetic direction
of the runway shall be used as the basis for determining the longitudinal axis.
TAKEOFF AREA-
(See LANDING AREA.)
TAKE-OFF DISTANCE
AVAILABLE [ICAO]- The length of the take-off run available plus the length of
the clearway, if provided.
TAKE-OFF RUN AVAILABLE [ICAO]-
The length of runway declared available and suitable for the ground run of an
aeroplane take-off.
TARGET- The indication
shown on an analog display resulting from a primary radar return or a radar
beacon reply.
(See ASSOCIATED.)
(See DIGITAL TARGET.)
(See DIGITIZED RADAR TARGET.)
(See PRIMARY RADAR TARGET.)
(See RADAR.)
(See SECONDARY RADAR TARGET.)
(See TARGET SYMBOL.)
(See ICAO term TARGET.)
(See UNASSOCIATED.)
TARGET [ICAO]- In radar:
a. Generally, any
discrete object which reflects or retransmits energy back to the radar
equipment.
b. Specifically, an
object of radar search or surveillance.
TARGET RESOLUTION- A
process to ensure that correlated radar targets do not touch. Target resolution
shall be applied as follows:
a. Between the
edges of two primary targets or the edges of the ASR-9 primary target symbol.
b. Between the end
of the beacon control slash and the edge of a primary target.
c. Between the ends
of two beacon control slashes.
Note 1: MANDATORY TRAFFIC
ADVISORIES AND SAFETY ALERTS SHALL BE ISSUED WHEN THIS PROCEDURE IS USED.
Note 2: This procedure
shall not be provided utilizing mosaic radar systems.
TARGET SYMBOL- A
computer-generated indication shown on a radar display resulting from a primary
radar return or a radar beacon reply.
TAS-
(See TERMINAL AUTOMATION
SYSTEMS.)
TAWS-
(See TERRAIN AWARENESS
WARNING SYSTEM.)
TAXI- The movement of an
airplane under its own power on the surface of an airport (14 CFR
Section 135.100 [Note]). Also, it describes the surface movement of helicopters
equipped with wheels.
(See AIR TAXI.)
(See HOVER TAXI.)
(Refer to 14 CFR
Section 135.100.)
(Refer to AIM.)
TAXI PATTERNS- Patterns
established to illustrate the desired flow of ground traffic for the different
runways or airport areas available for use.
TCAS-
(See TRAFFIC ALERT AND
COLLISION AVOIDANCE SYSTEM.)
TCH-
(See THRESHOLD CROSSING
HEIGHT.)
TCLT-
(See TENTATIVE CALCULATED
LANDING TIME.)
TDLS-
(See TERMINAL DATA LINK
SYSTEM.)
TDZE-
(See TOUCHDOWN ZONE
ELEVATION.)
TELEPHONE INFORMATION
BRIEFING SERVICE- A continuous telephone recording of meteorological and/or
aeronautical information.
(Refer to AIM.)
TENTATIVE CALCULATED
LANDING TIME- A projected time calculated for adapted vertex for each arrival
aircraft based upon runway configuration, airport acceptance rate, airport
arrival delay period, and other metered arrival aircraft. This time is either
the VTA of the aircraft or the TCLT/ACLT of the previous aircraft plus the AAI,
whichever is later. This time will be updated in response to an aircraft's
progress and its current relationship to other arrivals.
TERMINAL AREA- A general
term used to describe airspace in which approach control service or airport
traffic control service is provided.
TERMINAL AREA FACILITY- A
facility providing air traffic control service for arriving and departing IFR,
VFR, Special VFR, and on occasion en route aircraft.
(See APPROACH CONTROL
FACILITY.)
(See TOWER.)
TERMINAL AUTOMATION
SYSTEMS (TAS)- TAS is used to identify the numerous automated tracking systems
including ARTS IIE, ARTS IIIA, ARTS IIIE, STARS, and MEARTS.
TERMINAL DATA LINK SYSTEM
(TDLS)- A system that provides Digital Automatic Terminal Information Service
(D-ATIS) both on a specified radio frequency and also, for subscribers, in a
text message via data link to the cockpit or to a gate printer. TDLS also
provides Pre-departure Clearances (PDC), at selected airports, to subscribers,
through a service provider, in text to the cockpit or to a gate printer. In
addition, TDLS will emulate the Flight Data Input/Output (FDIO) information
within the control tower.
TERMINAL RADAR SERVICE
AREA- Airspace surrounding designated airports wherein ATC provides radar
vectoring, sequencing, and separation on a full-time basis for all IFR and
participating VFR aircraft. The AIM contains an explanation of TRSA. TRSAs are
depicted on VFR aeronautical charts. Pilot participation is urged but is not
mandatory.
TERMINAL VFR RADAR
SERVICE- A national program instituted to extend the terminal radar services
provided instrument flight rules (IFR) aircraft to visual flight rules (VFR)
aircraft. The program is divided into four types service referred to as basic
radar service, terminal radar service area (TRSA) service, Class B service and
Class C service. The type of service provided at a particular location is
contained in the Airport/Facility Directory.
a. Basic Radar
Service- These services are provided for VFR aircraft by all commissioned
terminal radar facilities. Basic radar service includes safety alerts, traffic
advisories, limited radar vectoring when requested by the pilot, and sequencing
at locations where procedures have been established for this purpose and/or when
covered by a letter of agreement. The purpose of this service is to adjust the
flow of arriving IFR and VFR aircraft into the traffic pattern in a safe and
orderly manner and to provide traffic advisories to departing VFR aircraft.
b. TRSA Service-
This service provides, in addition to basic radar service, sequencing of all IFR
and participating VFR aircraft to the primary airport and separation between all
participating VFR aircraft. The purpose of this service is to provide separation
between all participating VFR aircraft and all IFR aircraft operating within the
area defined as a TRSA.
c. Class C Service-
This service provides, in addition to basic radar service, approved separation
between IFR and VFR aircraft, and sequencing of VFR aircraft, and sequencing of
VFR arrivals to the primary airport.
d. Class B Service-
This service provides, in addition to basic radar service, approved separation
of aircraft based on IFR, VFR, and/or weight, and sequencing of VFR arrivals to
the primary airport(s).
(See CONTROLLED AIRSPACE.)
(See TERMINAL RADAR SERVICE
AREA.)
(Refer to AIM.)
(Refer to AIRPORT/FACILITY
DIRECTORY.)
TERMINAL-VERY HIGH
FREQUENCY OMNIDIRECTIONAL RANGE STATION- A very high frequency terminal
omnirange station located on or near an airport and used as an approach aid.
(See NAVIGATIONAL AID.)
(See VOR.)
TERRAIN AWARENESS WARNING
SYSTEM (TAWS)- An on-board, terrain proximity alerting system providing the
aircrew `Low Altitude warnings' to allow immediate pilot action.
TERRAIN
FOLLOWING- The flight of a military aircraft maintaining a constant AGL altitude
above the terrain or the highest obstruction. The altitude of the aircraft will
constantly change with the varying terrain and/or obstruction.
TETRAHEDRON- A device
normally located on uncontrolled airports and used as a landing direction
indicator. The small end of a tetrahedron points in the direction of landing. At
controlled airports, the tetrahedron, if installed, should be disregarded
because tower instructions supersede the indicator.
(See SEGMENTED CIRCLE.)
(Refer to AIM.)
TF-
(See TERRAIN FOLLOWING.)
THAT IS CORRECT-
The understanding you have is right.
360 OVERHEAD-
(See OVERHEAD MANEUVER.)
THRESHOLD- The beginning
of that portion of the runway usable for landing.
(See AIRPORT LIGHTING.)
(See DISPLACED THRESHOLD.)
THRESHOLD CROSSING HEIGHT-
The theoretical height above the runway threshold at which the aircraft's
glideslope antenna would be if the aircraft maintains the trajectory established
by the mean ILS glideslope or MLS glidepath.
(See GLIDESLOPE.)
(See THRESHOLD.)
THRESHOLD LIGHTS-
(See AIRPORT LIGHTING.)
TIBS-
(See TELEPHONE INFORMATION
BRIEFING SERVICE.)
TIME GROUP- Four digits
representing the hour and minutes from the Coordinated Universal Time (UTC)
clock. FAA uses UTC for all operations. The term "ZULU" may be used to denote
UTC. The word "local" or the time zone equivalent shall be used to denote local
when local time is given during radio and telephone communications. When
written, a time zone designator is used to indicate local time; e.g. "0205M"
(Mountain). The local time may be based on the 24-hour clock system. The day
begins at 0000 and ends at 2359.
TMA-
(See TRAFFIC MANAGEMENT
ADVISOR.)
TMPA-
(See TRAFFIC MANAGEMENT
PROGRAM ALERT.)
TMU-
(See TRAFFIC MANAGEMENT
UNIT.)
TODA [ICAO]-
(See ICAO Term TAKE-OFF
DISTANCE AVAILABLE.)
TORA [ICAO]-
(See ICAO Term TAKE-OFF RUN
AVAILABLE.)
TORCHING- The burning of
fuel at the end of an exhaust pipe or stack of a reciprocating aircraft engine,
the result of an excessive richness in the fuel air mixture.
TOTAL ESTIMATED ELAPSED
TIME [ICAO]- For IFR flights, the estimated time required from take-off to
arrive over that designated point, defined by reference to navigation aids, from
which it is intended that an instrument approach procedure will be commenced,
or, if no navigation aid is associated with the destination aerodrome, to arrive
over the destination aerodrome. For VFR flights, the estimated time required
from take-off to arrive over the destination aerodrome.
(See ICAO term ESTIMATED
ELAPSED TIME.)
TOUCH-AND-GO- An operation
by an aircraft that lands and departs on a runway without stopping or exiting
the runway.
TOUCH-AND-GO LANDING-
(See TOUCH-AND-GO.)
TOUCHDOWN-
a. The point at
which an aircraft first makes contact with the landing surface.
b. Concerning a
precision radar approach (PAR), it is the point where the glide path intercepts
the landing surface.
(See ICAO term TOUCHDOWN.)
TOUCHDOWN [ICAO]- The point where the nominal glide path intercepts the runway.
Note: Touchdown as
defined above is only a datum and is not necessarily the actual point at which
the aircraft will touch the runway.
TOUCHDOWN RVR-
(See VISIBILITY.)
TOUCHDOWN ZONE- The first
3,000 feet of the runway beginning at the threshold. The area is used for
determination of Touchdown Zone Elevation in the development of straight-in
landing minimums for instrument approaches.
(See ICAO term TOUCHDOWN
ZONE.)
TOUCHDOWN ZONE [ICAO]- The
portion of a runway, beyond the threshold, where it is intended landing aircraft
first contact the runway.
TOUCHDOWN ZONE ELEVATION-
The highest elevation in the first 3,000 feet of the landing surface. TDZE is
indicated on the instrument approach procedure chart when straight-in landing
minimums are authorized.
(See TOUCHDOWN ZONE.)
TOUCHDOWN ZONE LIGHTING-
(See AIRPORT LIGHTING.)
TOWER- A terminal facility
that uses air/ground communications, visual signaling, and other devices to
provide ATC services to aircraft operating in the vicinity of an airport or on
the movement area. Authorizes aircraft to land or takeoff at the airport
controlled by the tower or to transit the Class D airspace area regardless of
flight plan or weather conditions (IFR or VFR). A tower may also provide
approach control services (radar or nonradar).
(See AIRPORT TRAFFIC CONTROL
SERVICE.)
(See APPROACH CONTROL
FACILITY.)
(See APPROACH CONTROL
SERVICE.)
(See MOVEMENT AREA.)
(See TOWER EN ROUTE CONTROL
SERVICE.)
(See ICAO term AERODROME
CONTROL TOWER.)
(Refer to AIM.)
TOWER EN ROUTE CONTROL
SERVICE- The control of IFR en route traffic within delegated airspace between
two or more adjacent approach control facilities. This service is designed to
expedite traffic and reduce control and pilot communication requirements.
TOWER TO TOWER-
(See TOWER EN ROUTE CONTROL
SERVICE.)
TPX-42- A numeric beacon
decoder equipment/system. It is designed to be added to terminal radar systems
for beacon decoding. It provides rapid target identification, reinforcement of
the primary radar target, and altitude information from Mode C.
(See AUTOMATED RADAR TERMINAL
SYSTEMS.)
(See TRANSPONDER.)
TRACEABLE PRESSURE
STANDARD- The facility station pressure instrument, with
certification/calibration traceable to the National Institute of Standards and
Technology. Traceable pressure standards may be mercurial barometers,
commissioned ASOS or dual transducer AWOS, or portable pressure standards or
DASI.
TRACK- The actual flight
path of an aircraft over the surface of the earth.
(See COURSE.)
(See FLIGHT PATH.)
(See ROUTE.)
(See ICAO term TRACK.)
TRACK [ICAO]- The
projection on the earth's surface of the path of an aircraft, the direction of
which path at any point is usually expressed in degrees from North (True,
Magnetic, or Grid).
TRAFFIC-
a. 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.
b. Observation
of radar identified and nonidentified 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 AVOIDANCE 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 avoidance) 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
contraction 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. The display allows the traffic management coordinator 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 process of calculating a trajectory.
TRANSCRIBED WEATHER
BROADCAST- A continuous recording of meteorological and aeronautical information
that is broadcast on L/MF and VOR facilities for pilots. (Provided only in
Alaska.)
(Refer to AIM.)
TRANSFER OF CONTROL- That
action whereby the responsibility for the separation of an aircraft is
transferred from one controller to another.
(See ICAO term TRANSFER OF
CONTROL.)
TRANSFER OF CONTROL [ICAO]-
Transfer of responsibility for providing air traffic control service.
TRANSFERRING CONTROLLER- A
controller/facility transferring control of an aircraft to another
controller/facility.
(See ICAO term TRANSFERRING
UNIT/CONTROLLER.)
TRANSFERRING FACILITY-
(See TRANSFERRING
CONTROLLER.)
TRANSFERRING
UNIT/CONTROLLER [ICAO]- Air traffic control unit/air traffic controller in the
process of transferring the responsibility for providing air traffic control
service to an aircraft to the next air traffic control unit/air traffic
controller along the route of flight.
Note: See definition of
accepting unit/controller.
TRANSITION-
a. 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 transmission 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 automatically receives radio signals from
interrogators on the ground, and selectively replies with a specific reply pulse
or pulse group only to those interrogations being received on the mode to which
it is set to respond.
(See INTERROGATOR.)
(See ICAO term TRANSPONDER.)
(Refer to AIM.)
TRANSPONDER [ICAO]- A
receiver/transmitter which will generate a reply signal upon proper
interrogation; the interrogation and reply being on different frequencies.
TRANSPONDER CODES-
(See CODES.)
TRANSPONDER OBSERVED - Phraseology used
to inform a VFR pilot the aircraft’s assigned beacon
code and position have been observed. Specifically,
this term conveys to a VFR pilot the transponder
reply has been observed and its position correlated for
transit through the designated area.
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 FAILURE-
(See LOST COMMUNICATIONS.)
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