Why are the tips of wings curved up on some airplanes ?
Question asked by Emilie.
Winglets are vertical extensions of wingtips that improve an airplane’s fuel efficiency. Airplanes of all types and sizes are flying with winglets, from single-seat hang gliders and ultralights, to global jumbo jets. Some airplanes are designed and manufactured with sleek upturned winglets that blend smoothly into the outer wing sections. Add-on winglets are also custom made for many types of airplanes.
As an airplane wing moves through the air, low pressure is created on top of the wing, higher pressure is on the bottom. At the wing tip this higher pressure air flows into the lower pressure on top of the wing, in a circular motion, creating a vortex. This vortex of rapidly swirling air creates drag. In addition, the vortices created by wings of large aircraft can be dangerous to other aircraft behind. Winglets reduce size and power of wing vortices, thus reducing drag. Reduction of drag translates to approximately 5% improvement in fuel consumption of an airplane. Over time the fuel savings and reduction of carbon emissions are quite substantial.
The concept of winglets originated with a British aerodynamicist in the late 1800s. The idea remained on the drawing board until 1976, when Dr. Richard Whitcomb, a NASA aerodynamicist, conducted further research with winglets. Since the 1970s, when the price of aviation fuel began spiraling upward, airlines and aircraft manufacturers have looked at many ways to improve the operating efficiency of their aircraft. Winglets have become one of the industry’s most visible fuel-saving technologies and their use continues to expand.
A bit more about Captain Dan:
Captain Dan Baz enrolled in Flight School at the age of 16.
He has completed studies in Aircraft Engineering and Master of Business Administration. He has been at the controls of many different types of aircraft, from single engine Cessnas to large intercontinental jets on global routes.
Over the last four decades he has flown thousands of hours up in the blue sky.
Have a question for the Captain ? Send it to Captain Dan Baz email@example.com Every week a question from the readers will be selected and answer posted in this column.