Alternate requirements specify which conditions?

• A. One hour at normal cruise in still air with one engine
• B. Two hours at cruise with two engines
• C. 30 minutes at approach speed
• D. One hour at high altitude with one engine

Answer: (A)

Alternate requirements define the extra fuel you must have when you must divert to an alternate airport. They ensure you can reach the alternate and still have a safety margin to conduct an approach or hold. The standard planning margin is enough fuel to fly to the alternate and then hold or operate for about one hour at normal cruise with one engine inoperative, assuming still air. That still-air assumption gives the minimum endurance, since winds would change the actual time needed. The other durations don’t reflect the usual alternate fuel margin used in this context, and the specific wind/altitude conditions don’t override the basic one-hour reserve.