A leading-edge cuff is a fixed

aerodynamic Aerodynamics, from grc, ἀήρ ''aero'' (air) + grc, δυναμική (dynamics), is the study of the motion of air, particularly when affected by a solid object, such as an airplane wing. It involves topics covered in the field of fluid dyn ...

wing device employed on

fixed-wing aircraft A fixed-wing aircraft is a heavier-than-air Aircraft, flying machine, such as an airplane, which is capable of flight using wings that generate Lift (force), lift caused by the aircraft's forward airspeed and the wing configuration, shape of ...

to improve the stall and spin characteristics. Cuffs may be either factory-designed or an after-market add-on modification.Crane, Dale: ''Dictionary of Aeronautical Terms, third edition'', page 144. Aviation Supplies & Academics, 1997. A leading-edge cuff is a wing leading-edge modification, usually a lightly drooped outboard

leading-edge extension A leading-edge extension (LEX) is a small extension to an aircraft wing surface, forward of the leading edge. The primary reason for adding an extension is to improve the airflow at high angles of attack and low airspeeds, to improve handling an ...

. In most cases of outboard leading-edge modification, the wing cuff starts about 50–70% half-span and spans the outer leading edge of the wing. The main goal is to produce a more gradual and gentler stall onset, without any spin departure tendency, particularly where the original wing has a sharp/asymmetric stall behaviour with a passive, non-moving, low-cost device that would have a minimal impact on performance. A further benefit is to lowering stall speed, with lower approach speeds and shorter landing distances. They may also, depending on cuff location, improve

aileron An aileron (French for "little wing" or "fin") is a hinged flight control surface usually forming part of the trailing edge of each wing of a fixed-wing aircraft. Ailerons are used in pairs to control the aircraft in roll (or movement arou ...

control at low speed.

Terminology

Leading-edge cuffs were called droop concept or drooped leading edge (DLE), or modified outboard leading edge in technical reports on stall/spin resistance. In these reports and others

NASA The National Aeronautics and Space Administration (NASA ) is an independent agency of the US federal government responsible for the civil space program, aeronautics research, and space research. NASA was established in 1958, succeedi ...

reports on the same obj