What is the purpose of best glide speed in engine-out scenarios?

• A. To maximize rate of climb.
• B. To allow for the highest airspeed while maintaining altitude.
• C. To maximize the distance traveled using the best lift-to-drag ratio.
• D. To minimize fuel consumption.

Answer: (C)

In an engine-out situation, the goal is to convert as much of your altitude into forward distance as efficiently as possible. The airspeed that achieves this is best glide speed—the speed at which the lift-to-drag ratio is at its maximum. At this point, the airplane can travel the farthest horizontal distance for a given loss of altitude because drag is minimized relative to lift.

If you go faster than this speed, drag (especially parasite drag) increases and you lose range. If you go slower, induced drag rises as you near stall, also reducing glide distance. There’s no engine to sustain altitude or burn fuel in a glide, so maximizing glide distance—not climb, not just speed, and not fuel use—is the priority.