Pilot/Controller Glossary

TACAN-
(See TACTICAL AIR NAVIGATION.)

this pertains to the act of becoming airborne after
departing a takeoff area.

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.

TAKEOFF RUN AVAILABLE (TORA) " The
runway length declared available and suitable for the
ground run of an airplane taking off.

TACTICAL AIR NAVIGATION (TCAN)- An
ultra-high frequency electronic rho-thetir navigation aid which provides suitably equipped aircraft a
continuous indication of bearing and distance to the
TACAN station.

TAKEOFF RUN AVAILABLE [ICAO]- The length
of runway declared available and suitable for the
ground run of an aeroplane take-off.

(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.)

TAKEOFF DISTANCE AVAILABLE (TODA)" The
takeoff run available plus the length of any remaining
runway or clearway beyond the far end of the takeoff
run available.
(See ICAO term TAKEOFF DISTANCE
AVAILABLE.)

TAKEOFF DISTANCE AVAILABLE [ICAO]- The
length of the takeoff run available plus the length of
the clearway, if provided.
TAKEOFF HOLD LIGHTS (THL)" The THL
system is composed of in-pavement lighting in a
double, longitudinal row of lights aligned either side
of the runway centerline. The lights are focused
toward the arrival end of the runway at the "line up
and wait" point, and they extend for 1,500 feet in
front of the holding aircraft. Illuminated red lights
indicate to an aircraft in position for takeoff or rolling
that it is unsafe to takeoff because the runway is
occupied or about to be occupied by an aircraft or
vehicle.
TAKEOFF ROLL - The process whereby an aircraft
is aligned with the runway centerline and the aircraft
is moving with the intent to take off. For helicopters,

(See ICAO term TAKEOFF RUN AVAILABLE.)

TARGET- The indication shown on an analog
display resulting from a primary radar return or a
radar beacon reply.

ASSOCIATED.)
DIGITAL TARGET.)
DIGITIZED RADAR TARGET.)
FUSED TARGET.)
PRIMARY RADAR TARGET.)
RADAR.)
SECONDARY RADAR TARGET.)
TARGET SYMBOL.)
ICAO term TARGET.)
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 must be applied as follows:
a. Between the edges of two primary targets or the
edges of the ASR-9/11 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 must be issued when this procedure is used.
Note 2: This procedure must not be used when
utilizing mosaic radar systems or multi-sensor
mode.

TARGET SYMBOL- A computer-generated indication shown on a radar display resulting from a
primary radar return or a radar beacon reply.