A deliberately shaped twist in the wing design is called a washout. The wing is designed in such a way so that in flight, the angle of attack at the wingtip is smaller than the angle of attack at the wing root. Consequently, more lift is generated by the inner part of the wing, while less lift is generated at the wingtips.

At high angles of attack, the wing root section of the wing reaches the stalling angle of attack prior to the wingtip. Stalling at the wing root is preferable. The turbulent air that flows back over the elevator creates a buffet that the pilot feels on the controls. The buffeting acts as a warning sign of an impending stall.

Stalling at the wing root means that more lift is generated at the outer sections of the wing. This makes the airplane more stable in the event of an uneven loss of lift. Stalling at the wing root also means that the ailerons near the wingtips are more effective. In addition to this, the reduced pressure difference between the top and bottom of the wing at the wingtips leads to less leakage of the airflow around the wingtips, smaller wingtip vortices, and lower induced drag.