Final answer:
Dutch roll is less effectively damped at high altitudes when the yaw damper is inoperative, due to reduced air density affecting control surface effectiveness.
Step-by-step explanation:
Dutch roll damping is degraded at high altitudes with the yaw damper inoperative. The yaw damper is a gyroscopic device designed to automatically counteract the oscillatory yawing motion known as Dutch roll, typically in sweeping-wing aircraft. At high altitudes, the air density is lower, leading to less aerodynamic effectiveness of the control surfaces like the rudder and ailerons.
This, in turn, results in poorer natural damping of the oscillations, increasing the tendency for Dutch roll to occur. Without the assistance of a yaw damper, the pilot must work harder to maintain directional stability, especially during turbulence or when manual inputs are needed to correct the roll and yaw motions.
In aviation, dutch roll damping refers to the stability of an aircraft's yawing motion. It is controlled by the yaw damper system.
When the yaw damper is inoperative, the damping of the aircraft's dutch roll motion is compromised, which can lead to unstable and oscillatory yawing movements.
For example, if an aircraft experiences a disturbance that causes it to yaw from side to side, the yaw damper would typically counteract these motions and maintain stability. However, without the yaw damper, the aircraft's dutch roll motion would persist and may become more pronounced, making it more difficult for the pilots to control.