64.16 Thrust Reversers

64.16.2 Describe thrust reversal.

Thrust reversal, or reverse thrust, is the redirection of all or part of an engine's normal rearward airflow so that a component of thrust acts forward, opposing the aircraft's direction of travel.

The engine itself does not rotate in reverse. Instead, a thrust-reverser system changes the direction in which the engine airflow or exhaust gases are discharged.

Depending on the engine design, reverse thrust may be produced by redirecting:

• the hot exhaust gases from the engine; or
• the fan or bypass airflow of a turbofan engine.

Thrust reversal is used primarily after touchdown to assist in slowing the aircraft.

64.16.4 Explain the purpose and operation of thrust reversal.

The purpose of thrust reversal is to provide an additional decelerating force during the landing roll.

Reverse thrust helps to:

• reduce the landing roll;
• reduce the load on the wheel brakes;
• reduce brake wear and heating; and
• provide additional deceleration when wheel braking effectiveness is reduced, such as on a wet or contaminated runway.