What would a plane crash like the Air France one be like from inside the plane?

Factual Questions
1

I realize no one seems to be sure exactly what happened to the Air France flight that crashed in the Atlantic between Rio and Paris. But I’ve read a few expert opinions that suspect that roughly what happened is this: the plane was flying through a thunderstorm and severe turbulence (the pilots were possibly having to fly it manually - after ice blocked up certain autopilot instruments - and without certain gauges). This required it to fly within an exact speed range - too fast and it would start to break up in the pressure of the storm, too slow and it would stall, and with a plane that size in conditions that difficult the stall would be an irreversible one. Some experts have been suggesting the plane stalled and then started to break up in mid-air.

My question is, what would any of these scenarios be like from inside the plane?

  1. If a plane stalls: what happens, does the plane just start heading downwards? Are the pilots still vaguely controlling where it lands, like the plane Sullenberger landed in the Hudson?
  2. If a plane ‘breaks up in mid-air’: what does this mean and what would it be like for passengers? I have an image of planes splitting into separate pieces and just falling from the sky (something like an aerial Titanic), but I suspect it means something more like, crucial pieces getting ripped off the plane and forcing an emergency landing. Either of these? I read a news story which contended that, if the cabin is breached and loses pressure, all passengers would fall unconscious immediately, and that this is probably what happened on the Air France flight.
2

I have no idea, but I’d like to join you in the morbid curiosity of the scenario. I hope to god no one had to stay conscious very long to witness their demise, let alone plummet toward the ocean.

3

30 seconds to unconsciousness is a number I’ve heard a few times. When Payne Stewart’s plane depressurized at altitude we were assured that unconsciousness was “nearly instantaneous.”. Though several of the Challenger astronauts were apparently alive (if knocked out) when they hit the water (they deduced this from their emergency oxygen having been used – but of course there is no emergency oxygen available if your aircraft breaks up in mid-air). The Japan Airlines flight that crashed into a montain depressurized and people were alive till impact, but that happened during the climb, much lower than 35k feet.

4

Unpleasant.

I’ve had a book on (General Aviation) crash investigations on my shelf for a while, and I just picked it up the other day. I’ve only read the introduction, deciding I’d save it for my flights to New Orleans. Of course, by the time I read it this thread will no longer be topical.

Anyway. A ‘stall’ means an ‘aerodynamic stall’. A lot of people think it means the engines. Basically, when the air comes unstuck from the wings, the wings no longer generate sufficient lift for flight. Stall behaviour is different for different aircraft. Some stalls are mild, and some are nasty. For example, practicing stalls in a Cessna is fun. Stalling a rotor on a helicopter would be fatal. But generally, an airplane isn’t going to ‘fall out of the sky’ after a stall. Get the air flowing over the wings (lower the nose) and they start flying again. Usually. In wind shear conditions it might be more difficult. For one thing, wind shear is a change in velocity. You could recover from a stall and get into another one when you fly into another mass of air moving in a different direction.

Another factor is that an airplane can stall at any speed. Exceed the critical angle of attack (by hitting wind sheer or even overcontrolling) and you can stall. So let’s say you get into wind shear and stall. You point the nose down to recover. Then you hit different-direction wind. Suddenly you’re exceeding V[sub]NE[/sub] (never-exceed speed). I’m not going to run through every possible scenario, so let me just do this one. Your airspeed is much faster than the aircraft is designed for. Let’s say this causes flutter (fluttering of control surfaces). The control surface can’t take the stress and breaks off. Maybe it’s still attached by a control cable, and starts banging against the rest of the structure. Or maybe it puts the aircraft into a seriously wrong position. A tailplane that’s flapping in the breeze could tear off the aft end of the fuselage. Now you’ve got this huge twisting force on the wings, and they rip off. So the passengers would be in a tumbling tube with positive, negative, and other G-forces acting on them like one of those ring things you can strap into at a carnival.

As for losing consciousness after losing cabin pressure, I’ve been through an altitude chamber. One of the exercises was rapid decompression. We were in an antechamber with a simulated altitude of 8,000 feet. The main chamber was at like 30,000 feet. As the instructor lulled us into complacency with his lesson, a valve was opened between the chambers. Instantly the antechamber filled with fog as it lost its pressure. We donned out masks and hit the 100% switch. Nobody passed out. That was the most fun I had in the chamber. I wished we could do it a few more times. But we had our masks hanging off of our helmets. A passenger in an airplane that was breaking apart and tumbling would have little chance to grab the oxygen mask and would likely lose consciousness in just a couple of minutes.

5

I clicked over here thinking the Title said “Air Force One”. I hope the nsa doesn’t make the same mistake.
Anyway, my curiosity is piqued, so I’ll read this.
Peace,
mangeorge

6

Some misconceptions here.

An aerodynamic stall isn’t necessarily a catastrophic event - indeed it and the recovery can be reasonably easy (though this is much more likely to be true when the pilot is ready for it). There’s certainly no reason why it could not be accomplished in substantially less than 35,000’.

Oversimplified, a stall occurs when some aerodynamic surface (most often a wing) exceeds its critical angle of attack. The result is a rapid loss of a high percentage of the lift being produced. If both wings stall together the nose drops, angle of attack becomes substantially lower, the airspeed increases, and the plane flies off happily having lost some altitude. A stall that involves just one wing is more of a problem, as it tends to lead to a spin entry (typically a bit harder to recover from, and likely to consume more altitude but still by no means impossible).

The plane that landed in the Hudson River was under full control through the entire event (well, until it was in the water).

7

Helpful links:

Aerodynamic stall

Flutter

8

I’ve experienced lots of full stalls in a Cessna 172 (all purposeful, thank god). The airplane goes into a dramatic nose-down attitude very quickly. Different planes are different as Johnny pointed out, but if an airliner acts anything like a 172, then I’d imagine that the initial nose-down attitude would essentially shake the hell out of everything. My guess is that a very substantial number of people would be knocked unconscious almost instantly, not experiencing any of the rest of the flight.

9

One can only hope that the passengers and crew fell into unconsciousness in short order.

A human in free fall drops roughly 10,000 feet/minute. Granted different things drop at different rates in an atmosphere but lets go with that as a very rough guess.

Assuming that number and assuming* the plane plummeted straight into the ocean that is a 4 minute fall. The horror of that if you were conscious the whole way boggles the mind.
*- Note planes may not just “fall” straight down. IIRC TWA-800 had the front 1/4 of the plane fall off. The rest, including the wings, was in one piece. The reconstruction I saw showed the plane do a roller coaster maneuver…nose drops off plane loses weight up front and pitches up…plane stalls and pitches down…picks up speed, gains lift again and pitches up. Since the plane was at a relatively low altitude it is believed likely some passengers were conscious all the way.

10

I’m not particularly interested in the aerodynamics of what a stall is or how it occurs - I’d already read those wikipedia links about it - as I am in what it would be like for the passengers.

As for (2), does anyone know what ‘breaking up’ even means for a plane in mid-air? And what would it be like for the passengers?

11

:eek:

12

See post #4. I described one break-up scenario there.

To reiterate: Something breaks off. This results in over-stressing other things that break off. Passengers are thrown around violently. They are rendered unconscious or dead by being thrown about, or by hypoxia from not having access to supplemental oxygen.

13

Tangentially related:

The Free Fall Research Page. There are some survivors’ first-hand accounts of falling out of the sky without a parachute… others were unconscious throughout some or most of their free-falls.

Also, I’m reminded of the scene in Fight Club where the Narrator is imagining his own demise by airliner breaking up in the air. It was intended to be darkly humorous I know, but was done “realistically” enough it freaked the **** out of me.

Werner Herzog also made a film, Wings of Hope, about Juliane Koepcke, who survived after the plane she was in broke up in the air. (the only survivor, she fell two miles still strapped in her seat). Haven’t seen it, but it might provide some insight into what it’s like to be in such a crash.

14

As naval aviators say with their characteristic sangfroid, “Ruin your whole day.”

15

Former big jet pilot here …

Assuming the early overly-sensational news reports about flying through a thunderstorm followed by electrical problems are accurate, it would have been a pretty exciting experience for all aboard. Perhaps a peak experience for all.

Truly severe turbulence, enough to damage the aircraft, would be insane in the cabin.

Overhead bins would be opening, spilling stuff everywhere. Which would then be bouncing from floor to ceiling, over and over, along with anyone not belted in. There would be a lot of creaking and groaning noises as the cabin interior flexed along with the airframe. There are lots of joints in the interior to let it shift as the airframe flexes in normal flight, and they’d all be getting a max-case workout.

Meanwhile there is nearly continuous lightning outside. And the airplane is rolling side to side 20+ degrees every few seconds. Plus some drunken sideways lurches that are surprisingly unnerving in an airplane.

And 90% of the people are screaming. Maybe not at first, but the above conditions could easily last 5 minutes. Once the least stable person starts screaming, the mob effect quickly takes over.

Had they been lucky, about now they come out the other side of the storm line. Well over half the people have shit themselves, a couple dozen people have concussions or broken limbs from being hit with flying suitcases & stuff. A handful of people with weak hearts have had heart attacks & died. The airplane is fine, and the pilots divert to the nearest airport able to handle the injured. Which out over the Atlantic may be 2+ hours away.
But they weren’t lucky.

For whatever reason, the aircraft lost most electrical power and the pilots were flying off standby instruments.

Now it’s pitch dark in the cabin (except for the lightning outside). In a cruel irony, the “floor lighting will lead you to an exit” lights will be on. Not that those exits do any good 7 miles up.

Now the pitch and roll gyrations get more extreme. Flying a half-powered airplane off the standby instruments is damn hard.

Maybe they get a little too nose low and within a few seconds are over-speeding. Something breaks off. More likely, they got a little slow and that combined with an updraft caused an aerodynamic stall. if they hit a strong enough updraft, they don’t even need to have gotten slow.

Unlike the stalls described by light plane pilots above, stalling a big jet is quite a ride on a good day in smooth air. At night in extreme turbulence, it’s the coup de grace.

You’d expect a severe and nearly instant roll one way or the other, easily past 45 degrees, and maybe to 90 degrees or more. (i.e. one wing pointing straight down, the other straight up). Perhaps an engine breaks off as they are designed to do.

Then the aircraft either snaps over the other way, or tries to keep rolling onto its back. Full opposite control inputs may not be enough.

Now the nose starts to fall and the speed pick up. A couple more gyrations and they get it under control. Or they don’t, and from on its back they end up diving more or less vertically.

After 10-15 seconds of that, something catastrophic breaks off. A big piece of wing or tail. Now the unbalanced aircraft cartwheels more or less sideways. Within the next few seconds the fuselage breaks into several large pieces. At this point pressurization fails and the people are suddenly exposed to -30 to -50 degree temperatures and low pressure. As well as all the flailing wires and broken airplane chunks whipping around in the 300-600 mph wind. The lightning hasn’t stopped either.

Assuming you’ve got a good heart, are wearing your seatbelt and aren’t right at the edge of a chunk, you’re still 100% alive, conscious, & uninjured. Scared and doomed, but uninjured.

Due to the extreme adrenaline rush, folks will be using up blood oxygen at a furious pace. Many will lose consciousness due to lack of air pressure at altitude. But far from all.

And because you’re falling into thicker air at a pretty good clip, I’d wager all but the elderly will revive to at least a groggy state prior to impact. It’ll take 2-ish minutes for the fuselage chunks to fall to the sea. Many will be fully conscious and aware for the entire ride.

The final impact will kill 99% of the people, and critically injure the last 2 lucky (?) souls. Who’ll drown as their fuselage chunk sinks with them still strapped in.

All in all, probably a peak experience.

16

Here’s an example of an in-flight break-up of a GA airplane from Air Crash Investigation Of General Aviation Aircraft (removed illustration references):

17

That scenario (ie. what I called the ‘aerial Titanic’ scenario: the fuselage breaks into several large pieces, so passengers fall straight downwards, looking out into the sky, then sink strapped to the large pieces of metal) is pretty much the nightmare scenario that I was wondering about. I hope to God that’s not what happened to the Air France flight.

This was more what I figured ‘breaking apart in mid-air’ probably meant; crucial external pieces break off rendering the plane un-flyable, passengers quickly lose consciousness due to the turbulence or the loss of cabin pressure, and the plane head downwards fairly quickly. Not as bad as the scenario above but still not exactly pleasant. As far as the Air France flight goes I find it (morbidly) comforting that because the plane didn’t send any mayday signals other than automatic ones (including the automatic message that the cabin had lost pressure), that probably means the pilots fell unconscious very quickly, which hopefully means no one on board was conscious for whatever happened, especially if it was one of the scenarios painted here…

18

Oh, it’s just as bad. I was just trying to fit it into a nutshell. LSLGuy’s excellent post gave us the graphic details. (With the bonus about stall behaviour of big jets.)

19

People do not lose consciousness from turbulence, period. People lose consciouslness from depressurization slowly, over a span of 30-300 seconds depending on altitude & stress. All the while descending to thicker air.

The relationship between the curve of altitude lost & air pressure gained per unit time while falling versus the curve of time to unconscious at any given pressure pretty well guarantee that everyone other than the frail remain awake and alert throughout.
[pet rant mode=on]
I really do not understand the common mentality that keeps trying to assert that humans will become unconscious before they die unpleasantly. People, by and large, don’t.

Back after 9/11 there was a lot of discussion about how people jumping out of the buildings would somehow become unconscious. Bogus.

When someone is mauled by a zoo animal folks want to claim that the idiot who wanted to swim with the polar bears or cavort with the lions lost unconsciousness at the first hostile snarl. Not so.

Folks, the world does not work that way.
[pet rant mode=off]

20

I could envision a case where turbulence can cause unconsciousness: shaken-baby syndrome. I assume it could happen in adults as well. This is not to say that people losing consciousness by violent movement of their heads happens with any frequency, or that it has ever happened; but it seems plausible to me. That is, I’m not disagreeing with you; just saying that it might happen rarely.