Definition
The distance an airplane can travel forward through the air for a given loss of altitude after the engine has stopped producing thrust, expressed as a glide ratio (forward distance to altitude lost) and achieved by flying at the airplane's best glide speed in a clean configuration.
Plain English
How far the airplane can travel without engine power for every foot of altitude it gives up. Better glide performance means more distance to reach a safe landing spot.
Context Anchor
You see this term in engine-failure planning, especially when deciding whether a runway or landing area is within reach after takeoff.
Derivation
Glide comes from Old English glīdan, meaning to move smoothly without effort. In aviation it refers to flight without engine power — the airplane moving forward by trading altitude for distance.
Why Pilots Care
It determines whether a pilot can reach a safe landing spot after sudden power loss, directly affecting survival in engine-out situations.
Grounding Statement
If the engine quits after takeoff, glide performance is the realistic forward distance the airplane can cover before it reaches the ground.
Intuition Check
Glide performance does not mean the airplane can stay level or float indefinitely. It means how efficiently the airplane trades altitude for forward distance while descending.
Example Sentence 1
After the engine failed, the pilot pitched for best glide speed to get maximum glide performance and reached the airport with altitude to spare.
Example Sentence 2
Best glide speed is selected to maximize glide performance when returning to the airport from the traffic pattern.