What is a typical effect of Alternate Law on the flight control system?

• A. Alternate Law provides more protections.
• B. Alternate Law has full control authority and stability.
• C. Alternate Law disables autothrust.
• D. Alternate Law degrades protections and may limit control authority and stability.

Answer: (D)

Alternate Law represents a degraded flight control mode that occurs after certain faults. In this state, the protections built into Normal Law are reduced or removed, so the airplane relies more on pilot input with less automatic envelope guidance. Because protections are diminished, the flight control system may limit some automatic safeguards and the aircraft can exhibit reduced stability and less margin in handling—meaning handling becomes more manual and the pilot bears more responsibility to maintain the flight path. Autothrust behavior may be altered, and the overall envelope protection is not as robust as in Normal Law.

That’s why the statement describing degraded protections with potential limitations on control authority and stability best fits Alternate Law. The other options imply more protections, full authority, or a complete disablement of autothrust, which do not align with how Alternate Law typically behaves.