Reverse thrust is prohibited during which phase?

• A. In flight
• B. On landing rollout
• C. During taxi
• D. In hover

Answer: (A)

Reverse thrust is a ground-based deceleration aid. It is designed to help slow the airplane after touchdown, when the wheels are on the runway and the airflow over the wings remains in a controlled state. Using reverse thrust in the air would disrupt the aerodynamics, increase drag unpredictably, and could upset pitch, roll, or yaw moments and even stress the engine or airframe. For safety and controllability, reversers are inhibited above certain speeds and are permitted only during the landing rollout phase. That’s why the phase where reverse thrust is prohibited is in flight. During landing rollout you can use it under procedure, while taxi and hover are not applicable contexts for deploying reversers on a fixed-wing aircraft.