Why Do Airplane Wings Curl Up at the End?

Have you ever noticed that airplane wings curl up at the very end? Why is that? Called winglets, the curled tips shrink the vortices at the end of the wing, which in turn improves its fuel efficiency.

What’s cool is that this wingtip design is stolen from nature: birds curl their wings when they fly. Find out the fascinating history of winglets in the video by Real Engineering below.