How does Zero-G work in planes?

[Pugspaceprogram]

I have recently seen some videos on YouTube about zero-G planes, such as 'the vomit comet'. What i want to know is, how can we simulate zero-g on Earth, as in, within earths atmosphere?

[GJames]

They put the plane into a steep(ish) dive which simulates zero-g. Think of the van going off the side of the bridge in Inception if you've seen it, where everything floats up into the air. There is some more to it than that, but that's the general idea...

[Stochasty]

They put the plane into a steep(ish) dive which simulates zero-g.

Not a dive. A parabolic trajectory.

[Fractal_UK]

I have recently seen some videos on YouTube about zero-G planes, such as 'the vomit comet'. What i want to know is, how can we simulate zero-g on Earth, as in, within earths atmosphere?

The plane simply makes a rapid dive so that everyone inside is free-falling. That is why the experience of zero gravity can only be experienced for a brief period (i.e. before the plane reaches dangerously low altitude).

Remember that at the altitude of the International Space Station (for example), the gravitational acceleration is not significantly different to what it is on the surface of the Earth but due to their orbital velocity, they spend their time in a perpetual state of free-fall with the Earth's gravity acting only to keep them in orbit.

[Nibb31]

No, it's not free-falling or diving that causes the effect. It occurs also when the plane is climbing at the top of the arc.

Have you noticed, when you drive over a bump, there is a point where you are lifted from your seat ? Zero-G aircraft work in the same way. They fly up and down, in a parabolic flight path, and the weightlessness is just a transitory effect that happens for a few seconds when they are at the apex of the parabolic arc. It is countered by a higher G rating at the bottom of the arc:

Edited May 29, 2013 by Nibb31

[WestAir]

There are a whole bunch of nifty things an airplane can do that seems strange inside the cabin. Check out Bob Hoover.

If it were night time or you weren't looking out the window you'd have no idea the plane were even upside-down. Zero G is equally interesting, though it's more like the top of a roller coaster than real zero g. In fact, it's really exactly the same.

[PakledHostage]

Check out Bob Hoover.

That's almost better than Tex Johnston's infamous stunt... Almost.

[TheShadow1138]

The easiest way I can think to explain it is that as the plane crests and begins to descend it is accelerating towards the ground more than you are because its engines are adding to the acceleration the plane experiences from gravity while you only experience the acceleration due to gravity. Because of this the plane is "falling" faster than you are, and you experience "zero-g" because you are free-falling inside the plane until it pulls up.

[Pugspaceprogram]

Thanks for your submissions. Surprisingly, this was a test! I already knew but i wanted to test your knowledge. You were all correct! I congratulate you all. Why don't you try to simulate this in KSP. Do it. DO IT NOW!