Definition
The highest airspeed at which an aircraft may be flown with the wing flaps extended to any approved setting. Exceeding this speed risks structural damage to the flaps, their attachment points, or the actuating mechanism.
Plain English
The fastest you are allowed to fly with the flaps down. Go faster than this and you can break the flaps or the parts that hold them on.
Context Anchor
Seen in the aircraft limitations section, on airspeed limitation charts, and during approach and landing when the pilot is deciding whether it is safe to lower the flaps.
Derivation
The term is built from its parts, but one piece is worth flagging: 'flap' refers to the hinged panels on the trailing edge of the wing that extend downward to increase lift and drag at lower speeds. The whole phrase simply names the speed limit that applies whenever those panels are out.
Why Pilots Care
Exceeding this speed with flaps extended can bend or detach the flaps, leading to loss of control or requiring an emergency landing.
Intuition Check
Do not read “maximum” as a suggested operating speed. It is a limit, not a target. “Flap extended” means the flaps are moved out or down from their normal clean position, even if they are not fully down.
Example Sentence 1
She slowed the airplane to below the maximum flap extended speed before lowering the first notch of flaps on downwind.
Example Sentence 2
The white arc on the airspeed indicator shows the range from stall speed up to maximum flap extended speed.