With the X Bleed selector in AUTO, the X Bleed valve will ________________ when the APU bleed valve is open and the APU air is supplied to the pneumatic system.

With the X Bleed selector in AUTO, the X Bleed valve will ________________ when the APU bleed valve is open and the APU air is supplied to the pneumatic system.

• A. Remain closed
• B. Open
• C. Close
• D. No effect

Answer: (B)

The cross-bleed valve is there to connect bleed air sources to the pneumatic system when needed. In AUTO, it opens whenever bleed air is available from the APU and the pneumatic system requires air. If the APU bleed valve is already open and supplying air to the system, the X bleed valve will open to allow that air to feed the entire pneumatic system. It wouldn’t stay closed or have no effect because the automatic logic is designed to route available bleed air to the system when demanded.

The cross-bleed valve is there to connect bleed air sources to the pneumatic system when needed. In AUTO, it opens whenever bleed air is available from the APU and the pneumatic system requires air. If the APU bleed valve is already open and supplying air to the system, the X bleed valve will open to allow that air to feed the entire pneumatic system. It wouldn’t stay closed or have no effect because the automatic logic is designed to route available bleed air to the system when demanded.