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-   -   AF 447 report out (https://www.pprune.org/rumours-news/489790-af-447-report-out.html)

Lonewolf_50 6th Jul 2012 19:40

testpanel: no. I've read the entirety of the eight previous threads, and all of the reports issued to date less the one issued today. (As I am not finished with it, I may have a change of heart after posting this).

I can find no support for your statement. Yes, other crews adapted to the weather as they saw it differently, but it is well to remember:
a. weather is dynamic not static
b. each crew's weather avoidance scheme will be informed by what they see versus what was forecast
c. there is no evidence that moderate to sever turb was a factor in this mishap.

Fox3:

If the pilots are to blame, I'll suggest that they were in part set up by the system at Air France. Noted so far is the point that has been much discussed - evidence of their unfamiliarity with aircraft handling at 35K and above. That does not explain some basic CRM failures, which may be AF driven or personality driven, and also does not explain what looks to be a fundamental instrument scan breakdown.

bubbers44 6th Jul 2012 19:42

The captain knew how to fly but by the time he got to the cockpit doing his required legal rest they had things so screwed up he took a while figuring out how they could have done what they did.

Pilots should not be left alone in a cockpit if they can't handle a simple loss of airspeed problem without crashing into the ocean. The scarey part is how many flights tonight will be flown by equally unqualified pilots while the captain takes his required legal break? You are not allowed to be on duty in the cockpit for more than 8 hrs. Monitoring an autopilot for a few thousand hours at altitude does not mean you could fly it if the autopilot disconnected with no airspeed. AF447 proved that.

Loose rivets 6th Jul 2012 19:44

It has to be appreciated what kind of stall they were in. As stated in one of the early threads, the aircraft does not enter a 'true deep stall.' However, their flight profile, the feel, and basic instrument readings could have certainly given that impression to the average line pilot. The major difference would be, for a limited time/thousands of feet, they weren't trapped, as in a deep stall.

The incredibly powerful instinct to pull away from the ground - as suggested above - is I'm sure, very real, and to get another warning, when for a moment you do the right thing, must have bolstered that faulty reasoning considerably.

It probably wasn't long before fear affected the pilots' normally methodical reasoning. It's almost certain to be the case not long after their inflow of data became confused. Their situation must have seemed almost surreal in the latter stages. That is pretty solid psychology. Not a good state to be in when you need to willfully force your hand to obey an absurdly counter-intuitive command.

There are a lot of people better prepared now, as a result of this tragedy.


Pitot heads:

They're expensive, vulnerable and need complex translation before their data is displayed. They wouldn't have been there all these years if there was an easy alternative. However, I'm surprised there isn't a backup system based on alternative technology.

Air particles, and especially water droplets can be detected electronically and this used to measure speed. The trouble is, all the same ice issues apply, with the electronic detection being far more sudden in the way it fails.

CaptainSandL 6th Jul 2012 19:45

Northbeach

The idea that " XYZ" aircraft is incapable of being stalled should be eliminated, it is a dangerous error in thinking.
I agree, this is the mentality that did for the Titanic!


Sandy Swan

I would just like to urge all Airbus pilots to read BEA's AF447 Final Report. It is an education, plugs holes in our understanding and illuminates many areas left grey or fuzzy by our training.
Again, I completely agree. I would make it form the basis of our 6 monthly tech questionairre.

BOAC 6th Jul 2012 19:55


Originally Posted by L Rivets
There are a lot of people better prepared now, as a result of this tragedy.

- we must seek the 'good' from this disaster. LR has it. CaptainSandL's following post (#122) also.

We are stuck with the AB control philosophy - it will not change markedly. We have to make what we can of it. I hope new pilots will ponder well on this accident.

deSitter 6th Jul 2012 19:56

Mountain Bear said

"The 'startle effect' is an example of the over arching mental heuristic known as the recency effect. A different but related error is the primacy effect. The report makes clear that the pilot was primed to take the plane up because of the anxiety he had expressed about the plane's flight level prior to the incident. He went up because he wanted to go up; his training be damned. "

That's a great point. The same thing happened with the A300 that crashed on Long Island. The PF was overly concerned with wake turbulence and let his anxiety go to his feet, and he knocked the rudder off. To some extent it happened with the L-1011 at DFW, where the PF was spring-loaded to land in a storm when he should have gone around.

deSitter 6th Jul 2012 20:11

Well I think the proper bodies should mandate training flights in real aircraft with the AP is disconnected. Just normal hand-flying.

Petrolhead 6th Jul 2012 20:27

Why has no one asked what they were doing in that cloud in the first place? If they had not gone into cloud, the pitots would not have iced up.

Why did they not take vectors like other aircraft?

Was the radar display turned up so they could see it? - there are two parts to the ND display knob and I often see crews in the sim turn on the radar but leave it on min brightness so you cannot see it.

Something simple Airbus can do is to set the minimum brightness still visible.

ChrisVJ 6th Jul 2012 20:30

Sorry SadPole, anyone who has ever had a VW or GMC MAF Sensor problem will tell you a MAF measure is not the answer. Compared to a pitot tube they are unreliable, need a computer to translate the indication to anything useable and when they do go wrong they screw up everything around them.

By comparison a pitot tube is an elegant, simple and direct measurement that relies directly in a principle of physics. The only complication in this event is that the modification (heating) to cope with low temps and high altitude and water were inadequate. Not the fault of the basic principle.

kaikohe76 6th Jul 2012 20:48

di sitter,

Agree with you totally, see my post on page 4. Absolutely no substitute for a knowledge of simple basics principles, combined with plenty of manual hands on flying, all this prior to bringing on the automatics.

bubbers44 6th Jul 2012 22:01

The pitot tube for airspeed compared to static pressure is the only recognized way to display airspeed. Not having that, attitude and power setting using the charts on the aircraft is the alternate way to maintain stable flight for unusable airspeed. The two in the AF447 cockpit were not capable of doing this. Sometimes it pays to hire experienced pilots.

blind pew 6th Jul 2012 22:16

GPS
Yes some companies do have it fitted and used it for unreliable airspeed proceedures before the accident.

Flew the route with full enlarging crew - two captains. Copilots and engineers.
Always one captain in the flight deck and sometimes the resting captain would join us for the ITCZ transit.
Cheap option one captain - blame the companies and regulators.
As to the lack of airmanship from the captain!

deSitter 6th Jul 2012 22:40

Wouldn't the captain of anything make sure that matters were all boring and predictable before taking a snooze? I mean, was there any evaluation at all of the weather ahead?

bubbers44 6th Jul 2012 22:46

I can't see the captain being the problem. When they put themselves into a full stall he wasn't even there. The two FO's managed to do it all by them selves and when he got in the cockpit they were descending at 7,000 fpm in a stall and he in a glance is going to figure out how they totally screwed up a perfectly good airplane exept for the pitot tube malfunction? Could you?

bubbers44 6th Jul 2012 22:56

ds,yes if you had two captain you would have at least one experienced pilot in the cockpit but since RIO to Paris doesn't require two captains why would AF add the cost of an additional captain. Do like everybody else and get the FO's a type rating so they qualify to fly together. It is a lot cheaper having two FO's than two captains.

mini 7th Jul 2012 00:42

None of the guys driving that night were fools, some may not have had 10,000 hours experience but they were trained as well as the majority of pilots.

The real lesson here is that if it fooled them it could fool me...

Organfreak 7th Jul 2012 01:11

@deggers316:

Once terminal velocity is achieved (can't fall any faster), vertical acceleration ceases, and thus no Gs are felt.

Buried somewhere in the myriad threads might be the information on how long it took them to accelerate to TV. I, too, wonder if they didn't feel that.

:eek:

soylentgreen 7th Jul 2012 01:33

Empiricism / a Modest Proposal
 
Thanks to those who liked my post (my first post here -- long time lurker, thanks for being kind!)

Again, i'm not a pilot, but am a cognitive psychologist, so I'm sure I come at this from a different viewpoint.

To me, the question is this:

Given an identical situation, what % of professional pilots (or perhaps '3 man groups of pilots') would flub it and crash the plane?

There seems to be a contingent of forum members saying "0% : the AF guys were idiots".
There are others saying "100% : the AB design is at fault".

In my opinion, this is actually a very nice scientific question, amenable to research. Let's calculate this %age empirically.

Imagine this:

Get 100 x 3-man crews, and put them in a multi-day full-experience simulator. In this simulator, they fly full flights, sleep odd hours in weird hotel rooms, etc. Each crew does this for 30 days. 99% of the flights are uneventful.

At some point, each crew will get on 1% of their flights an AF447-type scenario. No warning, it just happens.

From this study, we calculate the ultimate data point: what % of crews survive. And perhaps more interestingly: what % of crews survive for the right reasons.

Expensive as hell? Sure.

Would it cost more than one AF447 tragedy? (Not snark: that's a serious question - how long would it take to do this study? I have no idea.)

The outcome would be quite interesting.

Reading the BEA report, the most interesting findings to me was the comparison to events "similar" to the AF447 event, which the BEA summarizes as follows (p 106, english edition)
  • 'Calling on the "unreliable airspeed" procedure was rare'
  • 'The triggering of the STALL warning was noticed. It was suprisging and many crews tended to consider it as inconsistent"'

So I propose (a modest proposal, being on a forum where we do nothing but argue) that we don't need to argue theory : The BEA has collected the pilot (ahem) study data for us...

Let's take the next step, do the real experiment and see what the data shows.

If, for example, 99% of fully-trained expert pilots flub this, then the "bad pilots" chorus would probably have to rethink their position.

If, for example less than 1% of fully-trained pilots flub this, perhaps that's more of an example of bad apples needing to be better-trained or weeded out?s

Or maybe in either case, we need to consider the human-machine interface as the thing that must change?

We could of course include variations and get lots of data : set the simulator up with A vs. B style controls. 2 vs 3 vs 4 man crews. Time since last slept. Time since woken up. Aurual vs. visual warnings. Fullt-time AOA sensors.

We could even include some stooges (experimental confidants) to mess with the results: what if half the simulated AF447 scenarios, the PF was in fact a trained experimenter who just holds nose up, and we see if the other 2 PNFs figure it out and overrule him?

Sounds like a fun experiment to me!

(NB - I'm sure a lot of this research has been already done, right? I'm not a researcher in this field, so I'd be surprised if these ideas are novel).

CafeClub 7th Jul 2012 01:49

two controls?
 
Apologies if this is covered elsewhere, but a search doesn't pull up a definitive answer... and I have NO wish to convert this to an A vs B thread.

What is the STATED logic from Airbus (they must have a reason) for input on one sidestick not to be felt on the other? As a previous poster points out this is low tech enough to be available (in a way) on every decent video game joystick?

Surely situational awareness would be greatly assisted by such a physical link between the controls? What is the manufacturers reasoning behind NOT linking "feel" between the sidesticks?

Organfreak 7th Jul 2012 02:41

CafeClub:

What is the STATED logic from Airbus (they must have a reason) for input on one sidestick not to be felt on the other?
I'd love to know what their official answer is, too.

In the likely event that they haven't commented on it, I'll posit the answer:

=Cheaper=. (A bunch.) :ok:

The override buttons and lighted cues were meant to replace the need for linked (yokes). This time they didn't.

No doubt, AB and its apologists will find a way to make it "a feature," not a cost-saving, neato, toy joystick. :hmm:
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