Well summarized BEagle.

bernie

The pitot tubes were frozen by extreme icing conditions that the heaters couldn't cope with - temporarily. Your other questions are ones that are still without answers.

There were lots of short cuts in the story portrayed by that programme, and the bit about immediately pulling fully back is simply wrong. This has been done to death before on the numerous threads here.

I'm not sure i was watching the C4 programme closely enough, were all of the the AI indications factual?

It seems to me that we have just a new special guest into the soap opera :E
So .. maybe it can be explained by the global warming effect ? :)
It is surprising that the BEA have not investigated this possible cause ... :ugh:

NAROBS, one cannot sense the velocity of falling (or any other velocity), only changes in velocity (accelerations). Have you never been in a lift and unable to tell whether it is moving or still? Ever been on a train and unable to tell whether your train is moving or the one next to it in a station?

The initial accelerations downwards would have been mixed in with various up and down sensations caused by turbulence.

Really? Please document.

NAROBS/others

I promise to be gentle: In the last few years the AF447 accident topics such as pitot heaters, crew behaviour, falling sensations, autopilot and back up instrumentation have been been discussed in great length and in much detail here in several Pprune threads :hmm:

I'm not sure many of us have the appetite to start that hamsterwheel rolling again, but "Search" and you shall find ;)

I'm with Jeremy Clarkson on 'global warming' - it's a load of total greenwash.

How come Britain was so warm that it was a major wine exporter in Roman times, yet we had a 'little Ice Age' in mediaeval times....? It's because the world's climate is a cyclical event over which the weeny-greenies can scratch their beards, rustle their sandals and fake as much information as they like, but can actually do nothing. That's simply the way of the world....literally. Telling us all to ride ethnic peace-bicycles, to worry about our 'carbon footprint' and to stop flying won't actually do a damn thing about the polar ice caps... But it's a convenient ruse for the government to con 'eco-tax' money out of us all.

Back to AF447. Normally there is suitable system redundancy to cope with a single sensor failure; even for total loss of airspeed there is a QRH 'unreliable airspeed' checklist. As Learmount said - it's basically to 'do nothing'. Just maintain a level flight attitude and maintain the thrust setting.... Why was the training and knowledge of the 2 AF co-pilots so abysmally weak that they were clearly unaware of this?

Not sure which bits were right in the programme, it said that the RH seat pilot continued to hold full up - with the correct take over procedure this would not matter, the other pilot presses a priority button (and the programme showed the priority left light illuminated), this locks out the other side stick (though there are ways of taking it back) making the fact that the RH seat pilot was holding full up irrelevant, so either the correct takeover technique was used and the LH pilot did not take stall recovery action or he did not use the correct method and the two sets of controls would have resulted in the control inputs being put together to give a combined input and the full up stick on the RH side VERY important.

GPS can provide ground speed but not airspeed*, so is not of great use in a situation where the pitot tubes fail. What happens if you're flying against/with a strong wind? Your airspeed could be vastly different to your ground speed.

Theoretically you could use some other type of force sensor (measuring dynamic pressure, for instance) but then you encounter similar problems to those of a pitot tube: If you have a dynamic pressure sensor then what happens if you fly through heavy rain, or hail/ice clouds? You'll get abnormally high dynamic pressures and thus inaccurate speeds. Pitot tubes are used because they are robust and of good accuracy, off the top of my head I can't think of any comparable alternatives.

*Unless you have other complementary data but that is hard to get and is not too accurate in a lot of cases.

There's a thread for people to voice inaccurate and/or badly researched opinions on this subject here: http://www.pprune.org/jet-blast/4710...ge-debate.html

Reading the report again it seems the PNH did take over correctly, but then the PH took it back, but without saying anything, there should have then been an automated "priority right" callout, but this may well have been missed in the chaos, meaning the LHS pilot thought he had control when he did not!

AF 447
 

At all times the a/c had two fully functioning engines, a Stby artificial horizon, a Sby compass, and a GPS Groundspeed readout available??

What more do you need, fly the plane!

I remember an early conversion detail on the B747-400, in the simulator. On a rolling takeoff I 'stood up' the Thrust Levers pressed TOGA and the instructor failed the Auto/Throttle, so the Thrust Levers did not move, so I discontinued the takeoff.
The instructor asked why, and I mentioned the lack of Thrust Lever movement, ''Whats your arm for ?'' he replied.

Easy to forget the basics.

I've said this on JB, but as pilots, what do you think of the Captain's apparent indifference to the Cu Nims he knew were ahead?

It seems to me as SLF that he took an astonishingly blase and relaxed view of them before retiring for a kip.

Other aircraft went around the storm.

And stop insulting each other! There is at least one highly respected member of this forum who lost colleagues/friends on that flight.

Being new to this hamsterwheel and not having read much of the previous 51 pages, I found the programme last night to be concise and helpful.

I don’t know if criminal negligence charges have been brought against Air France but they certainly should be. The unbelievable sense of arrogance from the Captain and his 2 idiots for co-pilots was shocking as was their complete inability to recognise a stall situation (which they caused) sitting around dumb struck while the aircraft plummeted to the ocean.

Those 3 people are at fault for this tragedy and Air France is equally culpable and people should serve time. The bottom line is that if that had been an African or other Third World operator you could bet that they would soon be on the EU black list and quite rightly so.

As for the technology debate I expect it’s already been done to death but it certainly doesn’t help when you’ve got a clueless Captain that he wasn’t able to see what the HP was doing to his side stick.

The whole thing made my blood boil when so called professionals were so utterly incompetent.

angels

I didn't see the programme but from reading the voice recorder transcripts I'd agree the captain's handover brief perhaps wasn't the most comprehensive I've ever read or heard but I wonder what would you'd expect him to say about the Cu Nims?

The AF crew had been briefed on the weather conditions along the route of flight, the Cu Nims were where they were forecast to be, all three pilots would have been taken weather avoidance around Cu Nims in the past, (though the most junior pilot probably wouldn't have been overly experienced in doing so). If I was in the captain's shoes that night I might have mentioned we were yet to cross the ITCZ/ line of Cu Nims but if I was talking to two supposedly rated co-pilots I wouldn't expect to have to brief chapter and verse the hazards of Cu Nims and techniques for weather avoidance........(and BTW as far as I understand the crew were attempting to go around "the storm" just before the pitot tubes froze).

HP

Then it might be worth you reading the previous 50 plus pages, plus the other threads on the subject,and better still read the official accident report which is freely available on-line, rather than simply relying on a TV programme's version of events.

FWIW we still don't know why, and we will probably never know why the two pilots at the controls behaved the way they did when the airspeed information "went missing", and whilst we may know what they did and said, we don't know what they perceived or were thinking.

As for the captain's actions - I rather suspect that by the the time he returned to the flight deck it was highly unlikely there was much if anything he could do.