How quickly must thrust reversers deploy and stow?

Thrust reversers are a critical component of aircraft that assist in decelerating the aircraft during landing. The deployment and stowing of thrust reversers must be accomplished within a specific timeframe to ensure effective performance and safety.

The answer indicating less than 5 seconds is correct because this timeframe is designed to optimize the aircraft's stopping capability while minimizing the risk of instability or control issues during landing rollout. Quick deployment allows the pilot to rapidly decrease the aircraft's speed, particularly in adverse conditions or during emergency situations. A slower deployment time could lead to inadequate braking performance and increase stopping distances, which is particularly important on shorter runways or in scenarios where immediate action is necessary.

In contrast, longer deployment times might compromise safety by delaying the reversal of thrust that is essential for quick deceleration, making the need for a response within a 5-second window critical in aviation operations.