The angle of attack limiter system is operational only when which control system is active?

The angle of attack limiter system is designed to enhance the safety and performance of the aircraft by preventing excessive angles of attack, which could lead to stalls. This system operates in conjunction with the pitch electronic flight control system (EFCS). The pitch EFCS is responsible for controlling the aircraft's pitch attitude and is critical for maintaining safe flight characteristics, particularly during critical phases such as takeoff and landing.

When the pitch EFCS is active, it can monitor and manage the angle of attack effectively, allowing the angle of attack limiter to engage and extend its protective function. This relationship ensures that the aircraft can maintain optimal performance and handling while avoiding loss of control due to excessive angles of attack.

The other control systems mentioned, such as roll EFCS, yaw EFCS, and SC/EFC (Stability Control/Envelope Flight Control), deal with different aspects of flight handling and stability, and they do not directly correlate with the operation of the angle of attack limiter. Therefore, the pitch EFCS is the only system that activates the angle of attack limiter, making it essential for its operation.