What type of engine air bleed valves are installed on the CRJ?

• A. ACSC controlled PRSOVs
• B. Manual PRSOVs
• C. Throttle-controlled valves
• D. AIPU controlled valves

Answer: (A)

Engine air bleed valves on the CRJ are designed to regulate and isolate bleed air automatically. They are implemented as PRSOVs—Pressure Regulating and Shutoff Valves—and on the CRJ they are controlled by the Air Conditioning System Controller (ACSC). The ACSC continuously monitors the bleed air demands from the environmental control system, cabin conditioning, and anti-ice needs, and it open or close the PRSOVs to maintain the correct bleed pressure and flow without pilot input. This automatic coordination keeps packs supplied with stable bleed air across different engine settings and flight conditions.

Manual PRSOVs would require pilot intervention and wouldn’t provide the automatic coordination the ECS needs. Throttle-controlled valves would tie bleed to engine throttle in a way that isn’t how the CRJ’s bleed system is designed to operate, and valves controlled by another unit like AIPU would imply a different control scheme not used for engine bleed in this aircraft.