Plain English Meaning

The speed to fly when the engine has failed or is at idle, so the airplane travels the farthest before it reaches the ground.

Full Definition

The airspeed at which an airplane achieves its most efficient unpowered descent, typically the speed that produces the greatest distance forward per unit of altitude lost (best glide speed) or, in some contexts, the minimum rate of descent. Best glide speed is published in the Pilot's Operating Handbook for a specific weight and configuration.

Context Anchor

You will see this term in engine-out practice, power-off approaches, and discussions, especially when an airplane is slow and descending in the .