What type of devices can be attached to the leading edge of an airfoil for increased lift?

The leading edge of an airfoil can be equipped with fixed and movable slats to enhance lift, especially at lower speeds or during takeoff and landing phases of flight. Slats are devices that extend out from the wing and create a slot or gap between the slat and the main wing, thereby allowing for smoother airflow over the surface. This modification helps to delay airflow separation, which typically occurs at higher angles of attack, thus maintaining lift at greater angles.

Fixed slats are permanently attached and serve to increase the camber of the wing, while movable slats can be adjusted during flight to optimize performance based on varying aerodynamic conditions. By increasing lift, slats effectively improve the overall maneuverability and safety of the aircraft during critical phases of flight.