How winglets work

A little bend makes aircraft quieter and more effi­cient: designed to improve lift, winglets are up- or down­turned extensions at the tips of wings.


A little bend makes aircraft quieter and more fuel-efficient: winglets—upturned or down­turned extensions at the tips of wings—improve an air­craft’s environ­mental perfor­mance by reducing drag and increasing lift.

Inspired by nature: Birds of prey have long wingtip feathers that they can spread out like a fan, which reduces air resist­ance and increases lift and speed. Richard T. Whitcomb, a specialist in aero­dynamics at NASA, adapted this principle for aviation in the 1970s, at a time when the oil crisis had caused prices for aviation fuel to sky­rocket. According to Whitcomb's calcu­lations, an additional vertical wing saves fuel because it increases the lift-to-drag ratio.

The principle: An aircraft’s lift is generated by low pres­sure on the upper surface of the wing and high pressure on the lower surface of the wing. Air flows up around the wing to balance out the low pres­sure. This air move­ment creates vortices, particu­larly at the wingtips, which coun­ter­act lift and increase kerosene consumption. Winglets are able to reduce these vortices.

How it works: Winglets break down the vortices at the wingtips into smaller eddies, which partly cancel each other out. This reduces flow resist­ance and improves lift—the air­craft rises faster and there­fore generates less noise while taking off. It also needs less energy in flight, which increases its range.

Net benefit: Winglets increase the weight of an air­craft, both with their own weight and also because of the structural rein­force­ments that need to be made to the wings. However, this negative effect is com­pen­sated for by the reduc­tion in fuel con­sump­tion, particularly on long-haul flights. The net outcome is that winglets lower fuel con­sump­tion by up to five percent.

Evolution: Wingtip designs can be very different. Airbus initially fitted com­mer­cial aircraft with wingtip fences, which have sur­faces extending both above and below the wingtip. Boeing devel­oped blended winglets, which are attached to the wing to form a smooth curve. More recent Airbus models have Sharklets, which curve up and back.

Taller than a man: Depending on the design, winglets can be quite large. The largest examples, measuring 3.45 meters, are fitted to the wings of the Boeing 767-300ER.

MTU Newsletter
MTU Newsletter

Receive regular updates on excellent service and top technology “made by MTU” with our newsletter, which also features a range of topics from the wider world of aviation.

You may also be interested in these articles:

Better flight connections

11.2016 | Dealing with the increase in worldwide air traffic between urban centers calls for new, quieter aircraft and more efficient airports. Big data applications also help get passengers and luggage to their destination more quickly.

“Sweet spot” for every aircraft

06.2017 | Analyst David H Perry (JP Morgan) explains in an interview why the C Series and E2 have taken over the title of most cost-efficient aircraft in the 100 to 130 seat category – and how Airbus and Boeing are responding to this new competition.