# Passengers in a falling plane, author request

1. May 6, 2013

### Govicide

I'm an author and I want to correctly portray a scene (with a bit of artistic license) in my next book. However, I don't think I understand the physics of the situation.

Scenario: Passengers flying in a G6 going 450mph at 35,000 feet. Jet goes into a nosedive at let's say a 45 degree angle, wings level. The jet accelerates towards the ground in its fall. What would the passengers experience? Would they tumble toward the cockpit if they were unbuckled? Would they be weightless? Would they hit the ceiling? Would they be forced toward the back of the plane due to the acceleration? Would it be a combination of all of these and more? If so, what would the order be?

And, if the jet pulls out of the dive, what would be the forces on the passengers? Once again, into their seats? Heads against the ceiling? Etc. . . .

Thanks in advance . . .

2. May 6, 2013

3. May 6, 2013

### AlephZero

To a rough approximation, tale a ride on a roller coaster, and transfer what you feel to the aircraft cabin situation.

If you are talking about a civilian passenger aircraft, any g forces big enough to "throw people around the passenger cabin" would be likely to make the wings fall off. Civil aircraft aren't designed to do aerobatics.

If any passengers were out of their seats and walking around, they might well fall over if they didn't grab hold of something to steady themselves, but that's probably about as "violent" as it would get.

The "vomit comet" is a very special case, because it is deliberately flown to maintain zero gravity for a short time. That wouldn't happen "by chance".

4. May 6, 2013

### A.T.

The begin of the dive might produce 0 or negative g-forces, so people would float around. This depend how quickly the nose goes down. Once diving in a straight line at 45 you are pushed mainly into the seats again, with some forward-backward-variation depending how fast you gain speed.

5. May 7, 2013

### CWatters

Alephzero - I dissagree. The Vomit Comet only generates about 1.8g pulling pull out of it's dive. Somthing a commercial jet should easily withstand.

When I was a child I flew in a turboprop aircraft that experienced sufficient -ve g for drinking glasses to hit the ceiling. Clear air turbulence is ocasionally severe enough to cause death and severe injury - one web site says that between 1981 and 1997 there were 342 reports of severe turbulence during which 3 passengers died and there were 80 serious injuries (usually taken to mean broken limbs). The aircraft usually survives to make a safe landing even if damaged to the point that they are later written off.

I believe the main problem with doing it deliberately is excess air speed. You can't produce zero g for long without building up excess speed and that might cause structural damage.

I agree with A.T. - If you want to make people weightless a 45 degree dive isn't going to do it because I doubt a jet could continue to accelerate fast enough like that. The vomit comet flies a parabolic path - it can generate weightless conditions even while climbing.

Last edited: May 7, 2013