Final answer:
The yaw damper disengaged light will come on when rudder pressure drops below a certain level or when yaw damper power is lost, indicating a malfunction in the system. This system is a crucial part of an aircraft's flight control system, helping to stabilize the yaw motion of the aircraft. Faults in the yaw damper circuit or a loss of power can also trigger the disengaged light.
Step-by-step explanation:
In aviation, the yaw damper is a system that helps stabilize an aircraft's yaw motion, which is the side-to-side movement of the nose of the aircraft. The yaw damper system includes rudder pressure as one of its inputs. The yaw damper disengaged light will come on when rudder pressure drops below a certain threshold, or when yaw damper power is lost, or when certain circuit faults occur within the yaw damper system.
For example, if there is a fault in the yaw damper system's circuitry or if there is a loss of power to the yaw damper, the yaw damper disengaged light will illuminate. This serves as a warning to the pilot that the yaw damper is not functioning properly. Rudder pressure is also monitored, and if it drops below a certain level, it can trigger the yaw damper disengaged light.
Overall, the yaw damper system is an important component of an aircraft's flight control system, helping to reduce yawing oscillations and improve stability during flight.