How long is the PTU inhibited after cargo door operation?

The PTU, or Power Transfer Unit, is inhibited for a duration of 40 seconds following cargo door operation. This is a precautionary measure to ensure that the hydraulic system remains stable and to prevent any potential interference or additional load on the hydraulic system during critical operations such as opening or closing the cargo doors. After this inhibition period, the PTU can resume normal function without affecting the aircraft's operations.

The inhibition duration is carefully designed based on the aircraft's hydraulic system dynamics and the need to maintain optimal performance and safety standards. This time frame allows for the system to stabilize after any changes in hydraulic pressure that may occur due to cargo door operations. Understanding the intentional design of this delay is essential for maintaining safety and efficiency in aircraft operations.