Slats are deployable panels on the front of a wing that open a gap, or slot, between themselves and the main wing structure. This gap forces high-pressure air from below the wing over the top surface, energizing the boundary layer and delaying airflow separation. They allow the aircraft to fly at a higher angle of attack and slower speeds, which is critical for short takeoff and landing phases.
Flaps 15, slats extended, gear down and locked for the approach.
When pilots select the first notch of flaps on many commercial jets, it is actually the leading-edge slats that deploy first.
Also heard as
- leading-edge slat
Do not mix it up with
- Flap: Slats are installed on the leading edge of the wing, while flaps are typically on the trailing edge.
Related terms
Flap
A hinged surface on the trailing edge of an aircraft wing used to increase lift and drag.
Leading edge
The forward-facing contour of an airfoil that first meets the oncoming air.
Angle of attack
The acute angle between the chord line of an airfoil and the oncoming relative wind.
Trailing edge
The rearmost margin of an airfoil where the upper and lower airflows rejoin.