Which combination is required to activate Emergency Descent Mode?

• A. Autopilot on, altitude above 20,000 feet, and CABIN ALT CAS displayed
• B. Autopilot off, altitude above 20,000 feet
• C. Autopilot on, altitude below 5,000 feet
• D. Autopilot on, altitude above 40,000 feet

Answer: (A)

Emergency Descent Mode is a controlled automatic descent that must be activated with the autopilot handling the flight path. It only engages when the aircraft is in a condition where a rapid, managed descent is appropriate, which means the autopilot must be providing control, you must be at a high enough altitude to execute a safe, automated descent, and the cabin altitude warning/monitoring indicator must be active so the system recognizes a cabin-pressurization issue that needs correction. So the required combination is autopilot on, altitude above 20,000 feet, and the CABIN ALT CAS display active. Without autopilot on, or if you’re below the threshold, or if the cabin-altitude warning isn’t displayed, EDM isn’t activated.