For how long do the PCUs provide rudder dampening against gust loads after hydraulic pressure is removed?

The correct answer is that the PCUs (Power Control Units) provide rudder dampening against gust loads for 12 hours after hydraulic pressure is removed. This duration is crucial for maintaining control and stability of the aircraft in case of unexpected weather conditions or handling anomalies after the hydraulic system failure.

The design of the PCUs incorporates specialized mechanisms that allow for continued rudder response to control surfaces, which helps pilots maintain directional stability even when hydraulic power is no longer available. This extended period provides a safety buffer, allowing for time to safely land or manage the aircraft following a hydraulic failure.

Understanding the time window for rudder dampening is essential for pilots and flight crews to effectively respond to emergencies, and is a key aspect of standard operating procedures regarding hydraulic system failures.