- T -
TA (Traffic Advisory) An alert issued by the TCAS/ACAS (–>) which informs the pilot that another aircraft is coming dangerously close to their aircraft. If the other aircraft does not immediately change its heading, this alert is followed by a Resolution Advisory (–> RA).
Take-off Clearance for take-off is issued by the control tower.
Taxiway Located between the apron area and the runways.
TCAS (Traffic Alert and Collision Avoidance System) An onboard anti-collision alarm system which warns pilots through use of visual and acoustic signals when two aircraft fail to respect separation minima (–> TA). The TCAS instructs the pilot to perform a vertical avoidance manœuvre (–> RA) if the pilot fails to correct the aircraft’s heading immediately (–> ACAS).
TMA (Terminal Manœuvring Area) The area of controlled airspace around an airport in which approaches and departures follow specific routes.
Tower (TWR) –> Aerodrome control
Traffic routes Traffic routes are formed by especially busy airways. This is the case for North-South and East-West continental and intercontinental traffic. The airspace controlled by skyguide includes two intersections of routes which carry some of the heaviest traffic in Europe. These routes generate numerous overflights, climbs and descents, which make this airspace one of the most complex in Europe.
Transponder (or radar responder) On-board equipment which communicates with secondary radar (–>) and transmits the aircraft’s identification code to ground-based systems.
TRINET Trinational audit organisation which forged a partnership between German, Austrian and Swiss (skyguide) air navigation services. TriNET performs independent analyses on the safety (–>) of technical systems and operational procedures.
Turbulence Irregular airflow, usually occurring where airflows or air masses mix. Turbulence can also be created by the passing of another aircraft. (–> Wake turbulence)