Which two flight controls are referenced as being controlled by the mechanical back-up input?

Which two flight controls are referenced as being controlled by the mechanical back-up input?

• A. Rudder; THS
• B. Rudder; Ailerons
• C. Elevator; THS
• D. Ailerons; Elevators

Answer: (A)

The test is about what surfaces have a direct mechanical backup path when the primary fly-by-wire system is unavailable. In the A320, the mechanical back-up input provides a direct, manual linkage to only two control surfaces: the rudder for yaw control, and the tailplane motion (THS), which changes the angle of the horizontal stabilizer and thus affects pitch (essentially providing elevator-like action through the tailplane). This means you can still yaw the nose and adjust pitch using the tailplane even if the electronic/hydraulic flight control system is inoperative. Ailerons aren’t wired to this mechanical path, and the elevator’s primary control relies on the FBW/hydraulic system, so they aren’t part of the mechanical back-up.

The test is about what surfaces have a direct mechanical backup path when the primary fly-by-wire system is unavailable. In the A320, the mechanical back-up input provides a direct, manual linkage to only two control surfaces: the rudder for yaw control, and the tailplane motion (THS), which changes the angle of the horizontal stabilizer and thus affects pitch (essentially providing elevator-like action through the tailplane).

This means you can still yaw the nose and adjust pitch using the tailplane even if the electronic/hydraulic flight control system is inoperative. Ailerons aren’t wired to this mechanical path, and the elevator’s primary control relies on the FBW/hydraulic system, so they aren’t part of the mechanical back-up.