What are the symptoms of an AHRS failure and how does the flight controls system respond?

• A. Attitude/heading degradation with possible loss of yaw dampers; standby indicators used.
• B. Attitude/heading degradation; autopilot automatically compensates with no backup needed.
• C. AHRS failure only affects the heading display but not attitude control.
• D. Attitude/heading degradation, possible loss of yaw dampers; system uses standby attitude indicators and degraded control laws.

Answer: (D)

When the AHRS fails, reliable attitude and heading information is lost, so you see attitude and heading degradation and the yaw damping can be lost or degraded. To keep the airplane controllable, the system switches to a degraded mode: pilots rely on standby attitude indicators for reference, and the flight-control computers operate under degraded control laws that provide basic maneuvering capability without the full protections and automatic stabilization of normal operation.