The takeoff altitude must not be more than how many minutes away from the departure airport at normal cruising speed with one engine inoperative?

• A. 30 minutes
• B. 60 minutes
• C. 15 minutes
• D. 90 minutes

Answer: (B)

Engine-out performance planning centers on staying within a known diversion envelope after liftoff. When one engine is inoperative, the airplane’s ability to climb, accelerate, and maneuver is reduced, so you must be able to reach a suitable airport within a safe margin. The standard planning assumption is you can reach the departure airport (or an alternate) within 60 minutes of normal cruising speed if an engine fails. This 60-minute limit provides a practical, consistent guideline for fuel planning, maneuvering, and landing options, ensuring you have enough time and energy to execute the required procedures and safely land.

Options like 15 or 30 minutes would not leave enough margin for the engine-out procedure and potential contingencies, while 90 minutes exceeds typical planning assumptions and could imply unnecessary risk or fuel planning complexities.