# eli5 When people jump with wingsuits what happens?

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They seem to have a lot of velocity forward, almost like they are flying. I cant understand how they seem to gain so much momentum forward without anything to propel them while they are falling/flying.

In my head they should just fall straight down but slower than they would without the wingsuits. Bc even if you jump forward off a cliff no way you gain that much momentum. And they don’t fall so slowly that even a little bit of forward velocity is enough to get as far as they do.

In: 2

They’re gliding. A large surface moving fast will produce a lot of force when air hits it. You correctly assume that this generally just slows you down, but if you angle yourself in a way that all the air gets redirected in a certain direction, you’ll start to accelerate in the opposite direction (to the expelled air) instead.

The wingsuits impart the ability to glide, albeit it’s a steep downward glide. With enough speed gained from gliding steeper downward, the pilot can pull up and briefly fly nearly level before resuming the steep downward glide.

Think of a fighter jet with short wings. It needs to fly at a high speed for the wings to generate enough lift to fly at all. If a fighter jet were to glide, it would be a steep downward glide pulling up at the end for a landing.

This is how the space shuttle flew also. It basically fell out of the sky, and near the end of the flight its nose was pointed nearly straight down in a supersonic dive, and then as it reached the landing zone it would pull up to allow its high velocity to let it fly level long enough to land.

The reason is in the name of the outfit. Literally a WING suit.

As such, it acts using the same principles of “lift” as any other wing. So, while gravity is pulling them “down”, the air moving over the top of the suit has a lower pressure than the air moving under the suit, creating “lift”. This lift has the effect of moving them forward, and the end result is what you see on videos . . . not so much an uncontrolled plummeting to Earth, but instead an angled descent, just as you see from a glider (though far steeper).

Taken from the air it looks like they are moving forwards quite fast but the ground they are flying over is steeper than it looks. Watch some of the videos taken from the ground as wingsuit flyers pass by. They are still falling extremely fast.