What Are Slats and Slots?

Leading edge slats are lift improvement devices (aerofoils) fitted to the leading edge of a wing to increase CLmax at high angles of attack. There are two different types of slats: fixed and automatic.

Fixed slats are mounted so that there is a permanent slot just behind the leading edge, which at high angles of attack channels airflow through and over the wing, reducing turbulence in the airflow.

Automatic slats are extended by air pressure at high angles of attack, opening the slot. At lower angles of attack, as the slat is retracted, it creates less drag than a fixed slot. Slats and slots, when extended, significantly increase the camber of a wing.