Why do fighter jets not have winglets?

Why do so many airplanes have a kink in their wing?

"What is that?" Many air travelers ask themselves when they let their eyes wander out of the aircraft window and discover the tip of the wing bent upwards. It is remarkable that there is still this surprise effect, after all, this wing shape has existed for almost 15 years. Since readers keep asking us about this phenomenon, today we answer the question: "Why do so many aircraft actually have a kink in the wing"? Take a look at the different "winglet" shapes in our photo show.

The name of this kink in the wing is called "Sharklets" (from the English word for shark) on Airbus and "Winglets" (from the English word for wing) on ​​Boeing.

But both names are repeatedly mixed up or confused and no longer clearly assigned to the different aircraft manufacturers. We will therefore stick to the term "winglets" in this article.

There are these pure forms:

  • The classic "winglets" are angular and inclined upwards.
  • "Blended Winglets" offer a flowing and round transition to the tip - the construction appears softer.
  • The "Wingtip Fences" are usually a bit smaller and aligned both vertically upwards and downwards.
  • And with the "Raked Wingtips" it is basically not a real "winglet", but an arrow-like extension of the wing.

Of course there are also various mixed forms, but the pure forms are sufficient to explain the basic principle, as their basic data are roughly identical.

Appearance isn't everything

No question about it, this wing shape gives the aircraft a more modern look, but that's not the background to this design. There are purely economic reasons, because the ends, which are usually 2.40 meters long, are bent and save three to seven percent on fuel. That would mean that an airplane can save up to a million liters of fuel a year. The modern shape increases the aspect ratio of the wing without increasing the wingspan. The curved ends reduce the drag created by air turbulence at the wing tips. This increases lift and reduces CO2 emissions at the same time.

The range also increases by up to 300 kilometers, depending on the type of aircraft, and it is possible to transport more weight. Studies also show that less turbulence on the wing leads to less aircraft noise. Since the "winglets" mean additional weight, the airlines have to calculate precisely whether the installation is really worthwhile. The largest "winglets" so far are installed in a Boeing 767 and offer a height of 3.45 meters.

The invention initially had a completely different reason

As is so often the case, the history of its origins is very bizarre and had nothing to do with today's use. Because back then it was really all about the optics. Well-heeled customers wanted their private jets to look different from other aircraft. The well-to-do travelers came in handy that this renovation looked even more elegant. In 1991, for example, the first aircraft to be equipped with "blended winglets" was a Gulfstream II business jet. More and more jets were retrofitted until the enormous savings potential became apparent, which the wealthy customers did not care about at first. The trend spilled over to the large aircraft manufacturers and became socially acceptable.