What is the CRJ maximum altitude for single pack operation?

• A. 31,000 Feet
• B. 28,000 Feet
• C. 32,000 Feet
• D. 34,000 Feet

Answer: (A)

The limit with a single pack comes from the environmental control system’s capacity. When only one air conditioning pack is supplying conditioned air, the system has reduced airflow and cooling/heating capability. The CRJ’s pack design is certified to maintain acceptable cabin temperature and pressure up to about 31,000 feet with just one pack. Beyond that altitude, the remaining pack (or the single pack’s capacity) isn’t sufficient to keep the cabin within specified limits, so operation above that altitude with only one pack is not permitted. So, the maximum altitude for single pack operation is 31,000 feet. If you need to fly higher, both packs must be available and operating.