Takeoff alternate requirements for three or more engines specify not more than how many hours from departure with one engine inoperative?

• A. Not more than 2 hours
• B. Not more than 1 hour
• C. Not more than 3 hours
• D. Not more than 30 minutes

Answer: (A)

Takeoff alternate planning for aircraft with three or more engines is about ensuring you have a feasible destination if you lose an engine during takeoff. The rule sets a practical limit on how far away that alternate can be when operating with one engine inoperative: the alternate airport must be reachable within not more than two hours of flight from the departure airport. This accounts for fuel, performance, and the ability to safely climb and maneuver with one engine out, while still giving you a reasonable buffer to reach a suitable landing site. The other timings don’t align with this operational standard: one hour or thirty minutes would be tighter than required for three-or-more-engine aircraft, and three hours would be too long to guarantee a safe diversion within normal fuel and performance margins.