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AF447 final crew conversation - Thread No. 1

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AF447 final crew conversation - Thread No. 1

Old 1st Nov 2011, 20:30
  #601 (permalink)  
 
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On extended leave but just got the BBC Ent (Polish) a full report of this incident. Old ground too but it does seem to be a case of blocked pitot tubes caused by supercooled water droplets. This was after a careful study of the meteorological conditions at the time. Looks like the crew were faced with a number of confusing indications. I have to say, at great risk on the PPRuNe pages, that 'Flight with unreliable airspeed indications' is a regularly practiced exercise in my present company. Another fave is to leave the seat, pretend to be in the forward loo, return (after closing your eyes) to find Handling pilot confused with a series of events. Sort it out as a crew. Most agree, good value & that was the point of my earlier offering. Return to the Flt-Deck and face something that needs to be corrected, quickly. That is what the Trainer did on my mate's Line Training even though it provoked much heated debate, later.
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Old 1st Nov 2011, 21:37
  #602 (permalink)  
 
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Originally Posted by chrisN View Post
Would it be beyond the wit of man to even devise a “computer knows best mode – it will recover as the pilots have not realised” before it’s too late?

Told you it was wild.
Not wild - that is exactly what AB Normal Law is.

Unfortunately in this case, normal law bailed out because of sensor failure, on the not-entirely-unreasonable logic that computer may not know best when it knows it is half-blinded.
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Old 1st Nov 2011, 22:03
  #603 (permalink)  
 
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Unfortunately when normal law went off line the pilots were not capable of going on line. It is a new problem caused by over reliance on automation and not competent pilots. I think the clock is ticking until the next one because nothing has changed. Competent pilots are expensive, new hires out of school are cheap. The bean counters have full control.
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Old 1st Nov 2011, 22:14
  #604 (permalink)  
 
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Originally Posted by HazelNuts39 View Post
I wonder if the system knows enough. It is latched in Alternate law because it doesn't trust airspeed anymore. Can it really trust AoA (one of the three is not functioning properly)? I would like to understand why, when the system reconfigures to Alternate law, the High-AoA protection reconfigures from an AoA reference to an airspeed reference. Is that because it doesn't trust AoA? Finally, the AoA value is zero when IAS<60kt. The system also 'knows' attitude and vertical speed. Is that enough?
Two levels of Alt law. If speeds have not failed, then it trusts those to keep some protections in place (Alt1). If speeds have failed, then it will latch the lower level of Alt law, with no protections in place.

Quite possibly it's this way round because airspeed was considered one of the more reliable air-data parameters...


Is attitude and vertical speed enough to warn on ? - I'm not sure. VS is coming, I think, from the same airdata that's dubious. What if there's static port failure ? If anything. I'd want to go to just the inertials - accelerometers should be plenty reliable enough over short time frame - and engine data only. Something like "if pointy end up, and engine power up and IRU says we going down, must be still stalled, or wings fallen off".

Need to be careful though that we're introducing a lot of complexity, and hence additional failure risk, into a very simple system (currently more or less "is aoa > threshold"). Stall warning failure is not good either.
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Old 1st Nov 2011, 23:05
  #605 (permalink)  
 
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Inexperienced pilots ? Both co-pilots had more hours than a lot of low cost carrier captains.. The pnf more than a lot of not so low cost captains. Methinks quite an experienced crew over all. As for rest periods you have to take them at some point. Who knows what reasons the capt took that break, maybe the lesser demanding part & he trusted his crew.
At least unlike some airlines where the co pilots only have 150-200 hrs which apparently is fine if they have appropriate training.
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Old 2nd Nov 2011, 02:40
  #606 (permalink)  
 
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150-200 hrs does not qualify anybody to fly an airliner across the Atlantic. 2000 hrs doesn't either. In our country it was 5,000 hrs minimum to be an FO on an airliner. Recently the bean counters have found a way to get cheap help at 350 hrs. Good luck.
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Old 2nd Nov 2011, 04:46
  #607 (permalink)  
 
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"Hours" are less and less relevant unfortunately. Especially for FO's flying long haul routes. Somewhere back in one of the previous threads this was covered with the approximiate math that the PF probably had something on the order of 9 hours a month of actual "PF" time with actual stick time literally measured in minutes (if any at all). So over the course of a year he might have 90-100 total flying hours with possibly a dozen takeoffs and landings and potentially less then an hour of "hands on" line flying.

So how unexpected is it really that under extreme stress and in totally unexpected circumstances he would fall back on the protections that had been heavily stressed in a low altitude stall recovery....in effect he appears to have been instinctively flying a missed approach type "recovery".

So the reality is that a bright carefully selected 300 hr (actual type specific with significant hands on stick/sim time) would be more likely to respond correctly then a more experienced pilot whose training was far in the past.

Personally I think this incident highlights how important actual hand-flying is toward maintaining situational awareness. My thought is that the over reliance on automation decreases the ability of the "PF" to actually be mentally "flying" the airplane which can lead to a mental "brain lock" when suddenly forced to assume flying responsibility. From all I've seen the AP disconnect left the plane relatively trimmed and stable with a slightly banked and nose down attitude at (or immediately after) disconnect. The flight control inputs required should have been very minimal and consistent with normal inputs in mild turbulence.

I've got to belive that the combination of surprise and a focus on low altitude upset recovery procedures led to an ingrained response that was completely incorrect for the specific circumstances.
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Old 2nd Nov 2011, 05:34
  #608 (permalink)  
 
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Originally Posted by SLFinAZ
Personally I think this incident highlights how important actual hand-flying is toward maintaining situational awareness. My thought is that the over reliance on automation decreases the ability of the "PF" to actually be mentally "flying" the airplane which can lead to a mental "brain lock" when suddenly forced to assume flying responsibility. From all I've seen the AP disconnect left the plane relatively trimmed and stable with a slightly banked and nose down attitude at (or immediately after) disconnect. The flight control inputs required should have been very minimal and consistent with normal inputs in mild turbulence.
If only the Airbus could be flown by hand.

The only time we get to fly by hand is the first and last 50 feet, or if something goes terribly wrong and we find ourself in direct law. As long as the FBW is in normal law, the SS is nothing more than a autopilot input device. Adding a bank request through the SS is the same as turning the heading select knob on the flight control panel. Both actions result in the autopilot turning the aircraft.

Hand flying an Airbus in normal law does not prepare one for hand flying an Airbus in degraded law. And we haven't even discussed hand trimming. It is virtually impossible to practice hand trimming. Yes, I have tried.

I routinely turn off AutoThrust, Autopilot, and Flight Director when flying visual approaches. All I'm accomplishing is to maintain my instrument scan. I have no confidence that my hand "flying" practice will translate to proficiency in degrade law ops.
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Old 2nd Nov 2011, 06:17
  #609 (permalink)  
 
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I repeat my 535 post as no 330 capt has disputed my 320 view that the RHS SS is visible from the LHS even if the lighting is down. You just have to look across the flight deck. OK when the capt appeared from the bunk he would struggle to see either SS from the jumpseat.

Tray table OUT or IN ?

Certainly with the table stowed the other SS is visible. I'll have do another check with the table out. Not 'til 13 Nov though.
My original check was to do with visibility in a dark flight deck.

This just made my day, that was funny!

How about a "smoke in the cockpit", AP unavailable due to some electrical cock-up that concoctes the smoke?
You have your goggles on and are battling to read and work the ECAM on old and faded screens. With no feedback whatsoever just try to "see" what kind of inputs your buddy is swinging ...

I bet you'd give one nut for some tactile feedback then.
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Old 2nd Nov 2011, 06:49
  #610 (permalink)  
 
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You do not leave inexperienced (albeit qualified) F/Os to penetrate the ITCZ.
FWIW, the older F/O had many more hours on type than the captain as well as considerably more experience in the ITCZ...
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Old 2nd Nov 2011, 07:57
  #611 (permalink)  
 
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Zorin 75

the older F/O had many more hours on type than the captain as well as considerably more experience in the ITCZ...
So then why didn't the Captain put him in control...Wouldn't have that made much more sense????
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Old 2nd Nov 2011, 10:45
  #612 (permalink)  
 
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A Question for Jet Drivers.

I fly helicopters and dont fully understand fixed wing. I sort of follow the stall that caused this crash but I dont understand how the Aircraft got into the stall in the first place.I seem to remember it happened at night so no external reference , and it happened in a storm so was the cause windshear caused by the updrafts downdrafts etc?Any explanation appreciated.
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Old 2nd Nov 2011, 11:25
  #613 (permalink)  
 
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The stall was caused by the pilot flying mishandling the aircraft.
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Old 2nd Nov 2011, 11:37
  #614 (permalink)  
 
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Things like 'experience' and 'qualification' seem to become more and more relative. Unless requirements are uniform, "qualifications" generally can be achieved in two ways - extensive and intensive training plus a certain dedication on part of the trainee OR by lowering requirements and artificially reducing the fail rate. Pretty much the same goes for ''experience" that is measured in hours/days/years. All depends on what person does most of this time. With advances in technology and increases in its reliabilty there must be pilots that would have thousands of hours and not a single malfunction just as there ARE people who never experienced things like a light bulb going off when they were alone and had to "deal' with it and there will be more people like that in the future.

In this context praising someone for obtaining "qualifications" or passing exam is premature unless you know what is required to qualify and what questions are asked at the exam.

It happens everywhere but it's very sad and definitely wrong that it seems to be happening in aviation. Human capital is the most expensive of all, this is where the costs always seem to grow and this is the one single area management ALWAYS look into when they want to increase the profit margins. I heard that aviation cannot be taken out of the context of the wider economy, but I think that it has to be. I suspect if regular economic enterprises were physically at the height of 10000 meters above the ground and keept there by the quality of the personel, the attitude to outsourcing scr*w-ups would be little bit different and the ratio of professionals knowing which buttons to press and WHY these buttons and not the others to office plankton only capable of pressing the learned combinations of buttons would be a bit higher.

The fact that both FO were "qualified" and type-rated yet there are number of things that they had never even been trained for speaks volumes. And its a huge regulator's failure that despite that they were allowed in the cockpit of a commercial passenger flight, and what's worse BOTH of them at the same time in the same cockpit. But unless this is strictly regulated to ther point of directly criminalising deviations it will be happening and will be happening more and more often. Nothing illegal after all, whereas it should be illegal just as its illegal to sell contaminated aviation fuel. And coming from corporate finance I know that generally companies will do as much (as little) as the regulation let them get away with. Humans in general do not often do more than is formally required.

And this is precisely the reason why I believe that Air France will be let off lightly considering that they just killed 228 people including their own staff. Unless regulation changes other big airlines might be tempted to follow their example. It's easier for them too - they are the ones that can afford the newer aircraft and better mainainance, so their estimated technology fail rate is lower and human factor doesn't play as big a role when everything works 100%.
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Old 2nd Nov 2011, 14:14
  #615 (permalink)  
 
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Punching through the ITCZ is not a habit to be recommended, serviceable pitots or not. I have done it several times and it is one of the worst flying experiences you can have. The Captain would have known that.
We will never know why they did not deviate 100, 200 or 300 miles to go around it. It is plausable the 1st and 2nd officers did not feel they had that sort of authority and did not want to wake the old man up for his say so. I think it was a grave mistake of the Captain not to have been there and the talk of him needing rest so as to be rested for the approach is laughable, there was another 7 hours for him to sleep after the ITCZ.
My guess is the plane would have deviated if he had been there. I mentioned at the vey beginning that I suspected the Captain not to be in the cockpit and was shouted down by the experts.
IMO it raises other issues of whether the younger generation of pilots are too hestitant to do things without a clearance. Did they ask for a deviation? Perhaps they did and could not get through or it was denied? Descend 500 feet and deviate anyway without a clearance but I think this sort of thinking outside the box is not encouraged in pilots anymore.
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Old 2nd Nov 2011, 15:55
  #616 (permalink)  
 
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hawker750, you talk much sense there.

Surely it would be prudent for the Captain to be on the flightdeck when approaching an area of hazardous weather such as the ITCZ? Is there not anything in the Air France Operations Manual which states this?

I think this sort of thinking outside the box is not encouraged in pilots anymore.
Sadly it often isn't know apart from some notable exceptions by some operators but you can't blame it on the individuals - they are merely a product of the "system".

There are times when you just have to have the moral courage (aka b***s) to do what you consider necessary and face the music later.
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Old 2nd Nov 2011, 16:23
  #617 (permalink)  
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Punching through the ITCZ is not a habit to be recommended, serviceable pitots or not. I have done it several times and it is one of the worst flying experiences you can have. The Captain would have known that.
-ah! That must be why a/c do it day in day out then, including several that night on that track. Are we not being a touch melodramatic? It's only a big front (think Dolly Parton...)
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Old 2nd Nov 2011, 16:33
  #618 (permalink)  
 
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BOAC
The two times I have had the misfortune of being caught in a cell in the ITCZ (both times because the radar lied) were not fun. Firstly in a King Air I went in at 28,000 feet and it spat me out at 38,000 feet, the 10,000 feet climb was dome with zero thrust. It destroyed the nose cone and had two lightning holes in the leading edge. The second time in a Hawker only destroyed the nose cone and dented the leading edges. I would deviate as much as it takes to avoid lines of CB's in the ITCZ
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Old 2nd Nov 2011, 16:42
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BOAC.
We probably flew together VC10's or 707's?
Quote:
ah! That must be why a/c do it day in day out then, including several that night on that track. Are we not being a touch melodramatic? It's only a big front (think Dolly Parton...)

I do not think I am being melodramatic. In a cell your margins for safe flight are dramatically reduced and it is crews' responsibities to mitigate risk as much as possible.
I'll bet the souls of the passengers now wish perhaps the crew had been a bit melodramatic
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Old 2nd Nov 2011, 16:56
  #620 (permalink)  
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Punching through the ITCZ is not a habit to be recommended
is the melodrama. You did not say 'punching through CBs' which we all agree is not a good idea. Remembering the ITCZ effectively encircles the world it makes it a bit of a challenge to 'go round the ITCZ' as you were suggesting - which is why hundreds of a/c have for YEARS flown through it.
We probably flew together VC10's or 707's?
- no.

Do we have, yet again, to tell YOU as well that they did not, as far as we know, 'punch through a CB' - unless you know differently, of course.

I can hear that Oozlum bird flapping again.
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