Definition
A wing flap that, when extended, opens a narrow gap (slot) between the flap and the trailing edge of the wing. Higher-pressure air from beneath the wing flows through this slot and energizes the airflow over the upper surface of the deflected flap, allowing the flap to produce more lift at higher deflection angles before the airflow separates and stalls.
Plain English
A flap that lets a thin stream of air pass through a gap between the flap and the wing when it is lowered. That extra airflow keeps the air attached to the flap longer, so the wing can produce more lift without stalling.
Context Anchor
Encountered in airplane aerodynamics, aircraft systems descriptions, and practical discussions of flap use during takeoff, approach, and landing.
Derivation
From 'slot,' a narrow opening or gap. The name describes the defining feature: a deliberate gap opens between the wing and the flap when the flap is deflected.
Why Pilots Care
Slotted flaps provide greater lift and better stall characteristics than plain flaps, enabling shorter takeoff and landing distances and safer low-speed flight.
Intuition Check
A slotted flap is not simply a flap with holes in it. The “slot” is the narrow gap that forms between the wing and the flap when the flap is extended.
Example Sentence 1
The Cessna 172 uses slotted flaps, which is why it can approach at a relatively slow speed without losing lift.
Example Sentence 2
Compared to split flaps, slotted flaps maintain better airflow over the wing at higher deflection angles.