The use of the EMERG DEPRESS switch above which altitude is prohibited?

• A. 15,000 Feet
• B. 7,000 Feet
• C. 20,000 Feet
• D. 25,000 Feet

Answer: (A)

Emergency depressurization is a rapid venting of the cabin to quickly relieve a pressurization issue or to purge smoke. But its use is limited by altitude. In the CRJ-550, you should not activate the EMER DEPRESS switch above 15,000 feet because, at higher altitudes, a sudden loss of cabin pressure can create unsafe conditions for passengers and crew and can overwhelm the oxygen system as you attempt a descent. The normal procedures expect you to descend and manage the cabin with the standard depressurization controls and oxygen supply rather than using the emergency depressurization switch at those altitudes.