What do the sidestick priority lights indicate?

The sidestick priority lights serve an essential function in the A320's flight control system, indicating which pilot has control authority over the aircraft's flight controls. When the Captain's sidestick priority light is illuminated, it signifies that the Captain has taken priority, and concurrently, the First Officer's sidestick inputs will not be processed if it is in a neutral position. This ensures that there is no conflict between the two pilots in operating the aircraft, allowing for a clear and structured approach to coordinated flight management during all phases of operation.

This system is crucial for safety, particularly in high-pressure situations where quick decision-making is vital. By designating priority, the sidestick lights help prevent confusion and maintain effective control of the aircraft by reinforcing which pilot's inputs are being recognized at any given time.