Winglets allow the wings to be more efficient at creating lift, which means planes require less power from the engines. ... Winglets help mitigate the effects of "induced drag." When an aircraft is in flight, the air pressure on top of the wing is lower than the air pressure under the wing.

What are the purpose of winglets?

Winglets are vertical extensions of wingtips that improve an aircraft's fuel efficiency and cruising range. Designed as small airfoils, winglets reduce the aerodynamic drag associated with vortices that develop at the wingtips as the airplane moves through the air.

Are winglets effective?

Flight tests showed that the winglets increased range by about 6.5 percent and improved directional stability.