Fatal Flight 447: Chaos in the Cockpit C4

[surveyor]

Fairly damning on the crew so far.

Did not realise they were in a stall, or set the plane up in a basic pitch and power format when they lost instruments. Sounds like the captain had a clue, but spotted too late that one of the pilots trying to pull back on the stick was cancelling out the other trying to get the nose down.

[dfen5]

Scary stuff. I still reckon you get an idea what these giants are doing in the air, 10 degree nose up at one point, they must have been able to feel the incline from their own senses? When coming in to land in the dark and not looking out I can tell it's nose up as a passenger..

[Ginetta G15 Girl]

dfen5 said:

When coming in to land in the dark and not looking out I can tell it's nose up as a passenger..

No you can't, you really can't. You will get the same sensation if the a/c were to carry out a level acceleration - It's called The Somatogravic Illusion and it can kill you very quickly if you believe it and not your instruments.

[LotusOmega375D]

It could have done without the posh lawyer's input. Best keep the talking heads of these programmes to aviation experts.

[anonymous-user]

Surely a simple spirit level type contraption on the dash would show the pitch as a fail safe in the event of instrument failure?

[Ginetta G15 Girl]

D3fender said:

Surely a simple spirit level type contraption on the dash would show the pitch as a fail safe in the event of instrument failure?

I'm afraid not because it would suffer from acceleration based errors.

[Bradgate]

AF 447 was one of the most serious and worrying incidents in aviation of the last decade. Modern airliners operated by major first-world carriers don't just drop out of the sky - but this one did. The investigation has uncovered serious issues with pilot training on glass-cockpit, fly-by-wire aircraft.

Those interested in in-depth discussion and analysis about AF 447 can find it here :

http://www.pprune.org/rumours-news/489790-af-447-r...

Edited by Bradgate on Sunday 16th September 22:23

[dfen5]

Ginetta G15 Girl said:

No you can't, you really can't. You will get the same sensation if the a/c were to carry out a level acceleration - It's called The Somatogravic Illusion and it can kill you very quickly if you believe it and not your instruments.

Blimey - I was a nervous flyer before watching that and hearing that too! How that chap pulling back on that stick for so long wasn't noticed or why he thought it a good idea..

[surveyor]

Ginetta G15 Girl said:

D3fender said:

Surely a simple spirit level type contraption on the dash would show the pitch as a fail safe in the event of instrument failure?

I'm afraid not because it would suffer from acceleration based errors.

From memory they did have an artificial horizon - one of the few instruments that was working. Is that enough to set the pitch and power, which from what I understand is what they should have done while they sorted out the rest?

Be interested to hear from a Pilot rather than armchair (especially myself) and media 'experts'?

[Simpo Two]

Ginetta G15 Girl said:

dfen5 said:

When coming in to land in the dark and not looking out I can tell it's nose up as a passenger..

No you can't, you really can't. You will get the same sensation if the a/c were to carry out a level acceleration - It's called The Somatogravic Illusion and it can kill you very quickly if you believe it and not your instruments.

Presumably the same way the Harrier 'simulator' fools you into thinking you're decelerating over a clearing just by tipping you forwards... except you know you're in a box fixed to the ground so you can work out what's actually happening.

I think the programme on 447 was discussed here some months back.

[Ginetta G15 Girl]

There are a whole raft of illusions that can utterly convince you that the a/c is doing something that it isn't - in RAF parlance these are generally termed 'the leans' and all Aircrew will have experienced them in some way, shape, or form in their careers. Fortunately the RAF trains its Aircrew in such a way that you are fully aware of these pitfalls from the earliest stage of training. Indeed there is a sort of simulator that is used during AvMed training that fully demonstrates these illusions within the safety of the classroom.

The bottom line is, if you get into a 'U/P' (unusual position) then by selecting a known POWER, ATTITUDE and TRIM the a/c will be where you want it to be.

If you don't have a functional artificial horizon, but you have a conventional 'Turn and Slip' instrument then, again, it is fully possible to regain 'straight and level' (albeit rather coarsely) with associated reference to the ASI and Altimeter.

Unfortunately I have no experience of how the Civies train (and especially not Air France), nor have I flown 'Glass Cockpit' a/c so I am not prepared to make a public judgement upon this case.

[davepoth]

It's a scary thought that if both pilots had said "fk it", left the plane to its own devices and gone back to the galley for a sandwich, they would have been quite likely to get to their destination without incident.

[Tango13]

Ginetta G15 Girl said:

There are a whole raft of illusions that can utterly convince you that the a/c is doing something that it isn't - in RAF parlance these are generally termed 'the leans' and all Aircrew will have experienced them in some way, shape, or form in their careers. Fortunately the RAF trains its Aircrew in such a way that you are fully aware of these pitfalls from the earliest stage of training. Indeed there is a sort of simulator that is used during AvMed training that fully demonstrates these illusions within the safety of the classroom.

The bottom line is, if you get into a 'U/P' (unusual position) then by selecting a known POWER, ATTITUDE and TRIM the a/c will be where you want it to be.

If you don't have a functional artificial horizon, but you have a conventional 'Turn and Slip' instrument then, again, it is fully possible to regain 'straight and level' (albeit rather coarsely) with associated reference to the ASI and Altimeter.

Unfortunately I have no experience of how the Civies train (and especially not Air France), nor have I flown 'Glass Cockpit' a/c so I am not prepared to make a public judgement upon this case.

It's possible to experience something similar whilst parking a car. I once pulled into a parking spot just as the car on my right started to reverse out, my inner ear was telling me I was stopped but my eyes were telling me I was still moving forwards. After standing on the brakes a bit harder and double checking the handbrake I realised it was a form of vertigo and stopped panicking

[FUBMW]

It's very important to note that the aircraft was descending with a sink rate of over 100000 m/s, hence they only had 2 minutes at best from when they started to be in 'real trouble'. When the autopilot was disengaged, the safety parameters that the computers govern with manual flight also disengaged. This is known as 'dIrect law' where the pitch and trim are not adjusted accordingly by the computer systems.

[hidetheelephants]

FUBMW said:

It's very important to note that the aircraft was descending with a sink rate of over 100000 m/s, hence they only had 2 minutes at best from when they started to be in 'real trouble'.

0.3%C! With that sinkrate you're really in trouble!

Edited by hidetheelephants on Monday 17th September 00:15

[FUBMW]

hidetheelephants said:

0.3%C! With that sinkrate you're really in trouble!

Edited by hidetheelephants on Monday 17th September 00:15

And that ladies and gents, is why significant figures are important. My apologies, 10000 m/s sounds about right. Still, that's a scary amount to comprehend for such a relatively inexperienced pilot. No shortcuts can be taken in the name of safety.

[hidetheelephants]

Have just watched it; once the AP goes off the 2/O just freezes on the stick, he doesn't seem to respond coherently to the F/O or the Captain. Even the stall horn doesn't shake him out of it, and the F/O not doing a proper 'Give me the fking stick!' command finishes it off. The Captain might as well have stayed in his bunk. Terrible way to go.

[Ginetta G15 Girl]

Simpo Two said:

Presumably the same way the Harrier 'simulator' fools you into thinking you're decelerating over a clearing just by tipping you forwards...

Basically yes - the 'box' tips forward which is sensed by the otoliths in your middle ear, however your eyes tell you you are upright and not angled forward, so your brain is fooled into thinking you are decelerating.

[Ginetta G15 Girl]

FUBMW said:

My apologies, 10000 m/s sounds about right.

Surely 10000 m/s is of the order of 33,000 ft/s? That figure can't be right for the Rate of Descent! If it were then the a/c would have gone from cruising altitude to impact in just over a second!

[Zad]

10km/s is of course 36,000km/h or Mach 30. That would orbit the earth in just over an hour. I think a decimal point may have been lost in translation.