Definition
The highest speed at which an aircraft may be flown with the wing flaps in any extended position. Exceeding this speed risks structural damage to the flaps and their supporting structure. On the airspeed indicator, the upper limit of the white arc marks this speed, designated VFE.
Plain English
The fastest you are allowed to fly while the flaps are out. Go faster than this with flaps down and you can damage them.
Context Anchor
Seen in the aircraft flight manual or pilot’s operating handbook, on cockpit placards, and during takeoff, approach, and landing configuration changes.
Derivation
Extended comes from the Latin idea of stretching or putting something out. In this term, it means the flaps have been moved out or down from their normal flush position on the wing, not that they have been physically stretched.
Why Pilots Care
Exceeding this speed while extending flaps or flying with them down can cause structural damage to the flaps or wing.
Intuition Check
Flap extended speed is not the speed at which the flaps move. It is the maximum airspeed allowed after the flaps are extended.
Example Sentence 1
She slowed the aircraft below the flap extended speed before lowering the first notch of flaps on the downwind leg.
Example Sentence 2
The checklist reminded the crew to observe flap extended speed during the approach configuration.