What is the maximum altitude for single pack operations in the CRJ 550/700/900?

The maximum altitude for single pack operations in the CRJ 550/700/900 is 31,000 feet. This limitation is set to ensure the cabin remains adequately pressurized and the environmental control system continues to function effectively under lower ambient pressure conditions. When operating with only one pack, the aircraft can maintain comfortable cabin conditions up to this altitude.

At altitudes above this threshold, the risk of inadequate cabin pressurization increases, and the performance of the remaining pack may not be sufficient to maintain desired temperature and pressure levels, which is why operating above 31,000 feet with a single pack is not allowable. Knowing this is essential for ensuring the safety and comfort of passengers and crew during flight operations.