Stall strips

A stall strip is a small component fixed to the leading edge of the wing of an airplane to modify its aerodynamic characteristics.

[1] These stall strips may be necessary for the airplane to comply with type certification requirements.

A stall strip typically consists of a small piece of material, usually aluminium, triangular in cross section and often 6-12 inches (15–30 cm) in length.

A stall strip initiates flow separation on a region of the upper surface of the wing during flight at high angle of attack.

[1] In some cases, such as the American Aviation AA-1 Yankee, both wings are designed to incorporate stall strips.

One of a pair of stall strips installed on an American Aviation AA-1 Yankee during manufacture
The CL-215 has a stall strip on the right wing only