During Emergency Descent Mode, what happens to the throttles?

• A. Auto throttles reduce to idle.
• B. Throttles remain at current setting.
• C. Throttles advance to maximum.
• D. Throttles cycle between idle and cruise.

Answer: (A)

In Emergency Descent Mode the autothrottle set-point goes to idle. This is done because the goal is a rapid, controlled descent to a lower altitude while keeping engine thrust minimal, which allows the aircraft to descend quickly without fighting the descent with thrust. The autopilot (or flight guidance) then manages the pitch to achieve the target descent rate, and you can always override with manual thrust if you need a different speed or to ensure certain performance. Keeping throttles at the current setting would slow the descent; pushing thrust higher would oppose the descent and slow you further or stall risk; cycling between idle and higher thrust would create an unstable or inconsistent descent.