What is the APR power (one engine) limit?

• A. 5 min
• B. 10 min
• C. 15 min
• D. 20 min

Answer: (B)

APR power on one engine is a temporary high-thrust setting used to maintain required performance when operating with one engine inoperative. The limit of ten minutes exists because running at APR power for longer than that can push the remaining engine and related systems toward thermal and mechanical limits, reducing safety margins. Ten minutes gives enough time to accomplish the intended maneuver or continue the approach while staying within approved operating limits; after that window, procedures call for reducing thrust or transitioning to a safer configuration to protect the engine and ensure controllability. Shorter durations wouldn’t provide sufficient performance in some scenarios, while longer durations risk overheating and higher wear.