Which procedure is used to descend when cabin altitude becomes unacceptable or for an emergency descent?

• A. Cabin altitude or emergency descent procedure
• B. Rapid descent protocol
• C. Steep approach procedure
• D. Descent with altitude hold

Answer: (A)

When cabin altitude becomes unacceptable, the priority is to bring the aircraft down to a safe altitude quickly so breathable air is available again. The standard response is the cabin altitude or emergency descent procedure. This single set of actions is designed to be started immediately and carried out in a controlled way to achieve a rapid descent, maintain aircraft control, and ensure passengers have access to oxygen as needed. It directly addresses both a cabin altitude excursion and an emergency descent, which is why it’s the best fit. The other options don’t describe a unified procedure for rapid, safety-focused descent: a steep approach is for landing on short runways, and descent with altitude hold wouldn’t actually descend.