Can air be taken from the 6th and 10th stages simultaneously?

• A. Yes
• B. No
• C. Only 6th Stage
• D. Only 10th Stage

Answer: (B)

Bleed air sources are selected and routed to the aircraft’s air distribution system through valves, valves that are designed so only one source feeds the system at a time. This keeps the pressure and temperature within safe, predictable ranges and prevents air from different stages from fighting each other.

Because the system uses a single active bleed source at a time, taking air from two different stages simultaneously would cause their pressures to conflict and could over-pressurize or destabilize the system. The plumbing and valve logic—including check valves to prevent backflow—are arranged to avoid that scenario. For these reasons, air cannot be taken from both the 6th and 10th stages at the same time.