AF447 wreckage located...

[magpie215]

DamienB said:

MarkK said:

A pilot is only going to commence stall recovery if they realise they are in a stall in the first place.

What, like a stall warner going off? Or perhaps the altimeter unwinding at a frightening rate? No excuses.

Maybe the stall warning system was frozen so never sounded.

Stands to reason that if this was caused by pitot/static icing that pitot heat was not selected so maybe stall vane heating was off too??

not sure on the anti icing setup on the scarebus.

[Marky Boy]

I'm not a pilot so can't comment on this too much. However even with the BEA press release, we still don't have the full picture of what the instruments were telling the pilots. I cannot believe that 3 experienced pilots would not have recovered the stall, had they actually known they were in one.

One can only speculate as to what other warnings and indicators they had in this situation. Until the official report is released I will not pass judgement on these pilots.

It reminds me of the Aero Peru 603 crash tbh, the amount of warnings, often conflicting, make me think that maybe the pilots didn't stand a chance.

http://www.youtube.com/watch?v=pXTbseOEFdQ

[anonymous-user]

DamienB said:

If experienced pilots cannot filter out the important information and fly the aircraft then clearly their experience is next to worthless - it's just hours boring holes in the sky. The basic stick and rudder flying techniques aren't being emphasized enough in their training - and their currency regime is failing badly.

You're being very critical about a situation that you appear to know very little about.

I assume before you passed judgement you made sure you were aware of all the facts and have experience of similar situations in similar weather. I had a go at recreating the AF447 incident in a simulator and it was absolutely horrendous. That's with knowing I was about to get it.

Sounds like you know best though.

[Chuck328]

el stovey said:

You're being very critical about a situation that you appear to know very little about.

I assume before you passed judgement you made sure you were aware of all the facts and have experience of similar situations in similar weather. I had a go at recreating the AF447 incident in a simulator and it was absolutely horrendous. That's with knowing I was about to get it.

Sounds like you know best though.

+1

[Simpo Two]

Well you guys can carry on staring at faulty instruments; I'll get me NVGs

The problem - obviously - is complexity. You don't need to be a Senior Captain to see that. They crashed because the system made an easy problem too complex for three pilots to solve.

[dvs_dave]

NVG's can't see through clouds so would be of no use.

What is puzzling though is how it wasn't obvious from a seat of the pants perspective that the plane was descending at an alaming rate whilst at a huge nose up attitute. Why weren't they gunning the engines to try to power out of the situation?

The final report will contain the answers but its still a very mysterious and terrible accident.

[Simpo Two]

dvs_dave said:

NVG's can't see through clouds so would be of no use.

I thought they'd be above the clouds at 36,000 feet - so there'd be a 'cloud horizon' if nothing else. There is certainly something of a frequency that can see through clouds, radar or IR or something of that ilk.

dvs_dave said:

What is puzzling though is how it wasn't obvious from a seat of the pants perspective that the plane was descending at an alaming rate whilst at a huge nose up attitute. Why weren't they gunning the engines to try to power out of the situation?

With no outside references they could only go by what the instruments were telling them, and because one/several of them were giving incorrect readings they couldn't solve the problem. The only other clue they have is G, and if there's roughly 1G straight down that's no help; your brain tells you you're flying straight and level. You can learn to ignore brain and use instruments, but when they're malfunctioning sadly there's sometimes no way out.

There was a case some years ago of an airliner that had a gyro stuck showing a slight amount of roll. Attempting to 'level the wings' the pilots banked irrecoverably and dived into the sea at 600mph - 1G all the way

[MitchT]

Simpo Two said:

I thought they'd be above the clouds at 36,000 feet

As I understand it they were flying through a severe thunderstorm. Large storm cells can rise to well above 40,000 feet. In some cases the only way past one is around it or through it. Over is not an option.

[DamienB]

magpie215 said:

Maybe the stall warning system was frozen so never sounded.

"Maybe?" Try reading the report!

At 2 h 10 min 51, the stall warning was triggered again. The thrust levers were positioned in the TO/GA detent and the PF maintained nose-up inputs.

(my bold)

El stovey - do you think that it's an acceptable standard of flying when three pilots cannot recognise a stall when a) the stall warner has sounded, b) the altimeter is unwinding (and presumably the standby VSI is also showing a frightening figure) despite full power and the AI showing positive pitch and c) the wings are dropping and having to be lifted every few seconds? They had 3 minutes to sort it, but there was only a brief and ineffectual attempt at lowering the nose. There is no real indication from the information released so far that they had even the slightest clue that they were in a battle for the lives of everybody on board.

Several other crews have successfully dealt with the same scenario without spearing 228 people into the sea at over 100mph. The conclusion may not be "cool" or PC but on the basis of the information released so far this crew performed poorly, end of...

[Munter]

DamienB said:

Several other crews have successfully dealt with the same scenario without spearing 228 people into the sea at over 100mph. The conclusion may not be "cool" or PC but on the basis of the information released so far this crew performed poorly, end of...

Given the data recorder has only recently been recovered. Have they been put through the same, or do you mean similar?

[Le TVR]

el stovey said:

I had a go at recreating the AF447 incident in a simulator and it was absolutely horrendous.

One thing I was unaware of was that the stall warning is only operative above 60 kts IAS? So the stall warning going on/off may not have meant what you might first think.....

Any idea what sort of Vls-Mmo margin they would have had to play with at the start of the upset?

[davepoth]

Le TVR said:

One thing I was unaware of was that the stall warning is only operative above 60 kts IAS? So the stall warning going on/off may not have meant what you might first think.....

Any idea what sort of Vls-Mmo margin they would have had to play with at the start of the upset?

http://www.pprune.org/tech-log/409310-a320-turbule...

Not that I have any idea about these things since the only planes I fly are paper and made of sales reports, but that would appear to suggest not very much at all.

[tank slapper]

DamienB said:

Several other crews have successfully dealt with the same scenario without spearing 228 people into the sea at over 100mph. The conclusion may not be "cool" or PC but on the basis of the information released so far this crew performed poorly, end of...

It's far too early to be making judgements like that. You have no idea what the instruments were displaying, and you have no idea what the crew were aware of or otherwise. It is very easy to sit in the comfort of your own home with a few vague snippets of information and point the finger after the fact. It is something else entirely to deal with it as it happens unexpectedly and without the knowledge of what exactly has failed.

[Mojocvh]

Le TVR said:

One thing I was unaware of was that the stall warning is only operative above 60 kts IAS? So the stall warning going on/off may not have meant what you might first think.....

Any idea what sort of Vls-Mmo margin they would have had to play with at the start of the upset?

The stall warning is driven not by airspeed but angle of attack.

[Roadrunner23]

MitchT said:

As I understand it they were flying through a severe thunderstorm. Large storm cells can rise to well above 40,000 feet. In some cases the only way past one is around it or through it. Over is not an option.

I understand that the storm had clouds towering up to 50,000 ft.

[magpie215]

DamienB said:

magpie215 said:

Maybe the stall warning system was frozen so never sounded.

"Maybe?" Try reading the report!

sorry missed that

[MitchT]

Roadrunner23 said:

I understand that the storm had clouds towering up to 50,000 ft.

Exactly. Which is why they wouldn't be above clouds at 36,000 feet as Simpo Two suggested they might.

Example of 'supercell' storm cloud:

[Simpo Two]

MitchT said:

Exactly. Which is why they wouldn't be above clouds at 36,000 feet as Simpo Two suggested they might.

That's a fair point. But is it normal for airliners to fly through such storms? They have radar, can they not avoid? Better to be late than risk passenger's lives.

[davepoth]

Simpo Two said:

That's a fair point. But is it normal for airliners to fly through such storms? They have radar, can they not avoid? Better to be late than risk passenger's lives.

That's one of the questions that needs to be looked at as I understand it.

[El Guapo]

davepoth said:

They had no idea how fast they were going, no idea which way the nose was pointing, and probably no idea what altitude they were at. pulling up rather than down seems like a sensible idea in the circumstances.

I have seen nothing in the preliminary report to suggest that there was any problem with the altimeter or attitude indicator.
The circumstances suggest that the crew initially believed that the aircraft was in a dive but soon afterwards, with engines at idle and the nose well up, how can they not have deduced that their continued rapid descent meant that they were stalled?
The man-machine interface seems to have been the problem; a trained pilot in a computerless aircraft at FL370, equipped with only thrust levers, altimeter and attitude control, would have been able to cope with a failed airspeed indicator.