## 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 (TCAN)- An ultra-high frequency electronic rho-theta air naviga- tion 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.) 

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, 

## T 

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

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

TAKEOFF 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 a display resulting from a primary radar return, a radar beacon reply, or an ADS-B report. The specific target symbol presented to ATC may vary based on the surveillance source and automation platform. 

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. 

## TARGET SYMBOL- 

(See ICAO term TAKEOFF RUN AVAILABLE.) 

(See ASSOCIATED.) (See DIGITAL TARGET.) (See DIGITIZED RADAR TARGET.) (See FUSED TARGET.) (See PRIMARY RADAR TARGET.) (See RADAR.) (See SECONDARY RADAR TARGET.) (See ICAO term TARGET.) (See UNASSOCIATED.) 

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. 

(See TARGET.) 

(See ICAO term TARGET.) 

