Why use winglets

Although not as popular as upward facing winglets, downward facing winglets perform much the same task. Depending on the type of aircraft, sometimes both upward facing and downward facing winglets are present. Though they are more recently visible on modern aircraft, downward facing winglets owe their most widespread usage to mid-century military jets.

A visit to an aviation museum featuring a Messerschmitt Me, a German World War II airplane, will reveal an early form of downward facing winglets.

Later, downward-facing winglets were known as the Hoerner wing tips, or Hoerner tips. They were named after Sighard F. Hoerner, who published a paper on the apparatus in the early 50s and conduced a great deal of research on wingtip vortices. After World War II, Hoerner tips mostly made their way onto gliders, sport planes, homebuilts, and light experimental aircraft. First introduced by Aviation Partners in , blended airplane winglets are sleek, highly effective wingtip devices which, unlike traditional upward facing winglets, are smoothly integrated into the wing.

Because the sweep of the area where the winglet meets the wing itself creates less drag than traditional winglets, blended winglets provide even more fuel efficiency.

Perhaps the type of winglet with the best name is the sharklet. Sharklets are present on Airbus A aircraft and are almost exactly the same as blended winglets. Airbus was in a legal dispute with Aviation Partners over the technology for several years. Is it possible to improve on a blended winglet?

Aviation Partners thinks so. In the mids, the company tested an open-loop design which sits at the end of the wing. Named spiroids, these devices were redesigned in the last decade. They just might show up as standard on a passenger jet near you before too long. Matthew A. Johnston has over 23 years of experience serving various roles in education and is currently serving as the President of California Aeronautical University. He is proud of his collaboration with airlines, aviation businesses and individual aviation professionals who are working with him to develop California Aeronautical University as a leader in educating aviation professionals.

By breaking up vortices, winglets reduce the drag on an airplane, which translates into fuel savings. The airflow around winglets is complicated, so designing them is tricky. Conventional upright winglets are currently used on a number of airliners, including the Boeing and the Airbus A and A This occurs when you're at high angles of attack. During takeoff and landing, you're slow - so you're at a high angle of attack and generating strong wingtip vortices.

When you're cruising at high altitudes, like a jet in the flight levels, the air is thin. So, you need a high angle of attack to generate enough lift to stay level, even though you're moving fast. Your wingtip vortices are stronger here, too.

Why do wingtip vortices generate drag? They actually angle your wings' lift backward, turning some of your lift into drag. A wing generates lift perpendicular to the relative wind. If you didn't have wingtip vortices, lift would point nearly straight up. However, the wingtip vortices curve up and around the wingtips, pushing the air flowing over the wing downward.

That angles your relative wind downward and tilts the lift vector backward. This causes two problems. First, some of your lift is now pointing backward, adding to drag. And second, you don't have as much lift pointing upward, countering weight.

So, to maintain level flight, you need to increase your angle-of-attack and generate more lift. And generating more lift means you're generating more induced drag.

This extra angle of attack you need is called the induced angle of attack. As a result, Boeing found the performance it was seeking without the need for vertical extensions. According to Gregg, the first-generation winglets fitted to aircraft such as the Boeing and the McDonnell Douglas MD11 offered up to 2. Second-generation winglets, such as those found on Boeing's workhorse , , and aircraft are much larger than the first-gen models, with greater curvature.

Get the latest Boeing stock price here. For you. World globe An icon of the world globe, indicating different international options. Get the Insider App. Click here to learn more. A leading-edge research firm focused on digital transformation. Good Subscriber Account active since Shortcuts.