What is the APU maximum altitude for bleed air use in the CRJ 200?

The maximum altitude for bleed air use from the Auxiliary Power Unit (APU) in the CRJ 200 is set at 15,000 feet. This altitude limitation is primarily due to the performance characteristics of the APU and the design of the aircraft's systems. At altitudes above 15,000 feet, the APU may not provide sufficient bleed air pressure or flow to effectively support the environmental control systems or engine starting procedures.

This operational parameter ensures that the APU delivers adequate air supply when needed, maintaining safety and operational efficiency. As the aircraft ascends, changes in atmospheric pressure and temperature can significantly affect the performance of the APU, which is why manufacturers specify maximum operational altitudes for various uses. Understanding these limitations is crucial for pilots and crew to ensure they adhere to the operational guidelines for safe aircraft management.