TEC.  See Tower En Route Control. 

Technique.  The manner in which procedures are executed. 

Telephone information briefing service (TIBS).  An FSS service providing continuously updated automated telephone recordings of area and/or route weather, airspace procedures, and special aviation-oriented announcements. 

Temporary flight restriction (TFR).  Restriction to flight imposed in order to: 

1. Protect persons and property in the air or on the surface from an existing or imminent flight associated hazard; 

2. Provide a safe environment for the operation of disaster relief aircraft; 

3. Prevent an unsafe congestion of sightseeing aircraft above an incident; 

4. Protect the President, Vice President, or other public figures; and, 

5. Provide a safe environment for space agency operations. 

Pilots are expected to check appropriate NOTAMs during flight planning when conducting flight in an area where a temporary flight restriction is in effect. 

Tension.  Maintaining an excessively strong grip on the control column, usually resulting in an overcontrolled situation. 

Terminal aerodrome forecast (TAF).  A report established for the 5 statute mile radius around an airport. Utilizes the same descriptors and abbreviations as the METAR report. 

Terminal arrival area (TAA).  A procedure to provide a new transition method for arriving aircraft equipped with FMS and/or GPS navigational equipment. The TAA contains a “T” structure that normally provides a NoPT for aircraft using the approach. 

Terminal instrument approach procedure (TERP). Prescribes standardized methods for use in designing instrument flight procedures. 

TERP. See terminal instrument approach procedure. 

Terminal radar service areas (TRSA). Areas where participating pilots can receive additional radar services. The purpose of the service is to provide separation between all IFR operations and participating VFR aircraft. 

Terrain awareness and warning system (TAWS). A timed-based system that provides information concerning potential hazards with fixed objects by using GPS positioning and a database of terrain and obstructions to provide true predictability of the upcoming terrain and obstacles. 

TFR.  See temporary flight restriction. 

Thermosphere.  The last layer of the atmosphere that begins above the mesosphere and gradually fades away into space. 

Threshold crossing height (TCH). The theoretical height above the runway threshold at which the aircraft’s glideslope antenna would be if the aircraft maintained the trajectory established by the mean ILS glideslope or MLS glidepath. 

Thrust. The force which imparts a change in the velocity of a mass. This force is measured in pounds but has no element of time or rate. The term “thrust required” is generally associated with jet engines. A forward force which propels the airplane through the air. 

Thrust (aerodynamic force).  The forward aerodynamic force produced by a propeller, fan, or turbojet engine as it forces a mass of air to the rear, behind the aircraft. 

Thrust line.  An imaginary line passing through the center of the propeller hub, perpendicular to the plane of the propeller rotation. 

Time and speed table.  A table depicted on an instrument approach procedure chart that identifies the distance from the FAF to the MAP, and provides the time required to transit that distance based on various groundspeeds. 

Timed turn.  A turn in which the clock and the turn coordinator are used to change heading a definite number of degrees in a given time. 

TIS. See traffic information service. 

Title 14 of the Code of Federal Regulations (14 CFR). Includes the federal aviation regulations governing the operation of aircraft, airways, and airmen. 

Torque. (1) A resistance to turning or twisting. (2) Forces that produce a twisting or rotating motion. (3) In an airplane, the tendency of the aircraft to turn (roll) in the opposite direction of rotation of the engine and propeller. (4) In helicopters with a single, main rotor system, the tendency of the helicopter to turn in the opposite direction of the main rotor rotation. 

