Definition
The highest airspeed at which the wing flaps may be extended or operated, designated VFE. Exceeding this speed with flaps extended can structurally damage the flaps, their tracks, or their attachment points.
Plain English
The fastest you are allowed to fly with the flaps lowered. Above this speed, keep the flaps up.
Context Anchor
Seen during approach, landing configuration changes, and instrument procedures where the pilot slows the airplane and extends flaps in steps.
Derivation
Maximum comes from a Latin word meaning “greatest.” Extension comes from Latin roots meaning “to stretch out.” Together, the term points to the greatest speed allowed while moving the flaps out from the wing.
Why Pilots Care
Extending flaps above this speed risks structural damage to the flaps or wing.
Intuition Check
Do not read “maximum” as a target speed. It is a limit. Do not read “extension” as meaning the flaps are already out; here it means the speed limit for moving them out.
Example Sentence 1
On the descent into the airport, she waited until the airspeed dropped below the maximum flap extension speed before lowering the first notch of flaps.
Example Sentence 2
During the approach briefing the instructor pointed out the white arc and reminded the student not to exceed maximum flap extension speed.