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AF 447 Thread No. 10

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AF 447 Thread No. 10

Old 12th Sep 2012, 01:32
  #361 (permalink)  
 
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Originally Posted by IF789
These guys knew they had UAS (cvr)
It is not what the CVR tells.
If the guys knew, why the PNF would have said :
Fais attention ta vitesse - Fais attention ta vitesse

As the BEA attributes to the NAV ADR DISAGREE ECAM MSG the first priority after the AUTO FLT AP OFF, why that message did show up only 2 minutes later ?
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Old 12th Sep 2012, 01:32
  #362 (permalink)  
 
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I think letting automation taking away your pilot skills because the company wants you to fly on autopilot all of the time is the problem. You forget how to fly manually.
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Old 12th Sep 2012, 03:29
  #363 (permalink)  
 
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Thanks, Tex and Bubbers

I look at the transcript and see the PNF call out repeatedly that "we are climbing".

yet the nugget in the other seat keeps pulling and pulling except for a few forward stick movements.

BEAM ME UP!

A basic altitude/speed indicator steam gauge would not have helped in this case due to all the other things the crew believed that HAL was doing to "protect" plus various audio alerts and such. Then there's questionable flight director cues. Gotta admit that if I had thot about UAS from reading previous incidents reports, I would prolly just hold what I had and slow down on any drastic stick inputs. Hell, wasn't like we were gonna hit the ground in a few seconds. That's just my gut reaction.

A simple warning that the air data was questionable for HAL could have allowed the crew to revert to manual flying, ya think?
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Old 12th Sep 2012, 16:54
  #364 (permalink)  

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Gums

Thenred cross over the speed takes tells you that the info is not available, neither for you nor for the HALs. What else do you need?

A felt 5000 pages of the threads talk abou infinitely fine details of many variations, but there is no real discussion to the real issue: why did the PF pull the stick like a madman and why did four eyes in other heads not capture basic instrument indications?

There were a number of other, smilar events REPORTED, where the crew obviously understood what to do. And we can assume that there were another many UNREPORTEd events as well. There are many airlines who still classify UAS events as non-reportable.

The question remains. Why did the PF pull?
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Old 12th Sep 2012, 17:15
  #365 (permalink)  
 
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If you want a conclusive answer, you are out of luck. A likely one(s), is right in front of us, confusion re: STALLWARN, STARTLE, INCORRECT Approach to STALL recovery, TOO MUCH information, FATIGUE, WEATHER, lack of experience in the domain, lack of understanding/training in the abnormal, poor FD design, poor STALLWARN design, CRAP CRM, Captain in the wrong part of the aircraft, animosity instead of teamwork, ET CETERA.

Any one of these could fluster anyone, and those who brag differently, are blowing smoke.

Start with: PF's initial NU was proper, its continuance was not.

Last edited by Lyman; 12th Sep 2012 at 17:17.
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Old 12th Sep 2012, 17:35
  #366 (permalink)  
 
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Hi,

TTex600:

Too bad. In the mean time, rest easy sitting in the back. The pilots are running those ECAM procedures in expert fashion. You just need to hope that they remember to fly the aircraft while they piece together the puzzle the aircraft lays on their table.



I would prefer to learn what HAL receives before it presents the puzzle. When it receives garbage it will present processed garbage. Richer, more complex.

Lyman:

...lack of understanding/training in the abnormal, poor FD design, poor STALLWARN design,...


Lack of understanding on UAS was the trigger in this case

Hunter58:

Thenred cross over the speed takes tells you that the info is not available, neither for you nor for the HALs. What else do you need?


Why not a retrofit? No HAL bandwidth problems, convenient redundancy, low cost implementation, etc. Why not?

We know the answer. (another set of HUMAN FACTORS)
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Old 13th Sep 2012, 07:13
  #367 (permalink)  
 
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AF pilots like stall ?
http://www.pprune.org/rumours-news/4...ml#post7410668
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Old 13th Sep 2012, 19:33
  #368 (permalink)  
 
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Why?

Thanks, Hunter. The same question that haunts me.

I see a PNF telling the nugget that "we are climbing". a few times

I realize that a "crewed" plane has to allow for experience and a clear chain of command. I do not see this with the AF477 crew. Not having flown a jet with more than one pilot ( me), I have trouble understanding the mentality of the "crewed" planes. My VooDoo experience had a RIO in the back seat with no flight controls, so the guy told me where to go, and "turn left", "climb", etc. I could also tell if I was pressing the envelope by his breathng rate on hot mike. Heh heh.

It is easy for us to say what we would have done. My guess is that the PNF was trying to decode all the ECAM messages and such, but still pointed out to the nugget that "we are climbing". I also believe that the PNF should have exerted his "seniority" in a forceful manner. But never having flown a jet with two "pilots", I am not "in the zone" with you heavy pilots.
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Old 13th Sep 2012, 21:07
  #369 (permalink)  
 
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Originally Posted by gums View Post
...due to all the other things the crew believed that [the systems were] doing to "protect"...
To be fair gums, that's speculation on the part of the PF's assumptions. Also, we know that the PNF called Alternate Law and should thus have been aware that there were no hard protections any more.

I suspect that the PNF didn't spend any more time than necessary "heads-down" in the ECAM, because shortly after making those calls he's verbally correcting the PF on his flightpath. If he saw "ALTERNATE LAW (NO PROT)", then it's likely he would have seen the preceding "NAV ADR DISAGREE" too.

I can't be certain, but I have to say that I don't think it's a question of inadequate annunciation of the UAS problem. The evidence suggests to me that the result of the PF's immediate instinctive action on AP disconnect quickly became a greater threat to the safety of the flight than the UAS, and it was that which caused confusion and indecision in the PNF. From that point onwards it becomes purely a CRM issue.

Last edited by DozyWannabe; 13th Sep 2012 at 21:24.
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Old 13th Sep 2012, 21:51
  #370 (permalink)  
 
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Problem I see as a dinosaur from single seat planes is lack of authority from the more experienced PNF. Hell, I was the aircraft commander for my whole career. Only had about 4,000 hours, but damned near that many landings, maybe more. I used the A/P all the time to allow me to scan an approach plate, set my IFF, etc. I even allowed HAL to follow the ILS when in the VooDoo. Just to see how good he was. My 100/one-eigth landing was pure manual, with super talk vrom a Navy chief on the PAR scope.

As with others, I can't believe the nugget would pull back and hold it for so long. I completely understand the insidious approach to stall and then actually getting into the stall. The plane obviously has great aero, so no severe shaking or wing rock or....... Hell, the F-102 I flew a hundred years ago and the Concorde just had increased sink rate as you slowed down or pulled hard. BFD. The Deuce was so docile that one of my classmates damaged the main gear by trying to "flare" and then having a severe sink rate at touchdown. I think that the Mirage pilots here will have similar war stories.

I shall still maintain that the PF and the PNF were thinking that HAL would "protect" them from extreme AoA, even tho' the stall warning was displayed over and over.

'twas a sad day/night. I assign some fault to the plethora of warnings/cautions and such, with no clear indications of what was FUBAR. But my main feeling is what Bubbers and others have opined - hold what you got and take a few seconds to get squared away.

that;s my feelings, folks....
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Old 13th Sep 2012, 22:09
  #371 (permalink)  
 
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Originally Posted by gums View Post
I shall still maintain that the PF and the PNF were thinking that HAL would "protect" them from extreme AoA, even tho' the stall warning was displayed over and over.
I say again - the PNF knew they were in Alternate, so he should (and probably did) know that there were no hard protections from that point.

The grey areas are where procedures and drills meet human psychology, especially the facet of human psychology that instinctively tries to deny that the problem or danger could be as great as it is. We saw it at Tenerife when the F/O and F/E let the Captain take off despite both of them being unsure of their safety, we saw it with Birgenair 301 when the two F/Os could see what was happening and yet did not physically take control and - outside of aviation - we saw it twice at Chernobyl when the shift leader refused to believe that his bungling the safety test could have destroyed the reactor, and later when the plant director ignored the level of radiation leakage from the portable equipment (which indicated 15,000 roentgens/hr), instead preferring to believe that it was at a relatively safe level as indicated by the plant's equipment (which went off the scale at 3.6 roentgens/hr).

Another potential HF issue recalls the Kegworth crash, when radio calls distracted the crew from performing troubleshooting that could have clued them into shutting the wrong engine down. The AF447 PNF was clearly monitoring the ECAM initially, but his attention was drawn away by the attitude of the aircraft following the PF's stick inputs.
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Old 13th Sep 2012, 22:15
  #372 (permalink)  
 
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should thus have been aware that there were no hard protections any more.
Dozy, you say this in retrospect, and with the benefit of three years, plus, of dicsussion of this issue.

You are making an assumption unsupported by any evidence we have.

It cannot be known that he
a) knew that
b) associated that at the moment with his immediate flight problem.

Whatever he knew

as opposed to whatever was or wasn't written in various manuals, was or wasn't covered in training, was or wasn't reinforced in various training

he may have also made an assumption about what the PF knew (as you are doing with him). This would shed some light on why it seems to have taken him a while to realize that something other than a bit of basic airwork was the problem over there in the right seat.

If he ever grasped that.

The AF447 PNF was clearly monitoring the ECAM initially, but his attention was drawn away by the attitude of the aircraft following the PF's stick inputs.
Could be, and likely ECAM and multiple screens took up much of his attention.

That leaves us lacking in understanding why a particular procedure was not called out and executed: the UAS drill that has been much discussed for the past year or so.

According to you, he knew that too.

Knowledge not applied often appears equivalent to ignorance, eh?

(See also Scripture, from the Book of James: Faith without works is dead. Or as they say in Missouri: Show me!).

Aviate-Navigate-Communicate is the order of operations for the crew, not just the guy with stick in hand. If the other gent is having trouble flying, you help him do that first, get the rest of it sorted out later.

Well, that's what I was taught in CRM.

And to ice that cake, I'll never forget the day another crew member, in an aircraft with retractable gear, reminded BOTH of us pilots up front that "we ought to have the gear down to land" just before we began our flare. We took his advice, and he drank for free for more than one day.

Basics first.

By the whole CREW.

Last edited by Lonewolf_50; 13th Sep 2012 at 22:22.
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Old 13th Sep 2012, 22:28
  #373 (permalink)  
 
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@LW50

I appreciate what you're saying and you may be right. However, the fact is that once outside of Normal Law, there are no protections which will hold the aircraft in a safe attitude in spite of the PFC input. 2-3k hours on type mostly in autopilot can explain the lack of manual handling ability, but it cannot explain the lack of knowledge of the systems on which they relied.

The loss of hard protections in *any* Alternate Law mode is down in black and white in the FCOMs and should be basic required knowledge when flying the type. This is why I found the hamster wheel regarding the Alternate modes so baffling, because in any flight law outside of Normal, the aircraft will follow PFC input right through Alpha Prot and Alpha Max if that input is sustained.

I'm speculating openly on HF issues with possible regard to this accident - I'm not claiming any certainty over what might have happened.

You mention a timely reminder to lower the gear - and I'm absolutely with you on that whole sentiment regarding A-N-C and CRM. That's why I'm speculating that the second the PNF noticed the unusual attitude, it effectively drew his attention away from the technical troubleshooting and quickly became his overriding concern (hence saying it was a CRM issue from that point onwards!)

Last edited by DozyWannabe; 13th Sep 2012 at 22:37.
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Old 14th Sep 2012, 00:17
  #374 (permalink)  
 
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Thanks, Wolf.

Sure glad Doze ain't up front analyzing all the data and trusting HAL. Whew!

Hell, the thing is acting like we designed it. It's "their fault". etc, etc.

The AoA "protections" should have remained in force, as actual CAS never got below 60 knots. Many ways to verify the AoA inputs, and AoA is prolly the most important flight parameter for all phases of flight.

I re-read the CVR and see the PNF reminding the nugget that "we're climbing", two or three times. No clue as to what the PNF did after that or during that. But the nugget kept pulling, maybe believng that HAL would prevent a stall AoA.
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Old 14th Sep 2012, 00:28
  #375 (permalink)  
 
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Originally Posted by DW
then it's likely he would have seen the preceding "NAV ADR DISAGREE" too.
That message was not preceding anything ... it came up much later, far too late to give valuable information to the crew.
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Old 14th Sep 2012, 00:38
  #376 (permalink)  
 
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@gums:

"HAL" told the crew that - for the moment - it couldn't deal with the speeds, and the PNF seems to have been aware of that fact. The flight control system never did anything untrustworthy - the annunciator system used the <60kts value to inhibit Stall Warning (albeit very late in the sequence), but I suspect that it would have been the same in any other modern type.

Maybe I'm expressing myself in a way that's hard to understand, but I'd like to know where you get the "Dozy trusts HAL" idea from, when it has no bearing on anything I've said.

As soon as Alternate Law is triggered and latched - even if the AoA protections remain in force - they cannot counteract a sustained PFC input because the system is designed to defer to the human pilot if Normal Law cannot be maintained. If I recall correctly if the aircraft is flying the soft protections will attempt to return the aircraft to a safe attitude if the stick is released, but in this case the stick was never released.

It's possible that the PF either never heard or failed to understand the consequences of the PNF's "Alternate Law" call, but the idea that the PF believed the hard protections were still active can never be anything more than speculation.

@CONF iture - reference? [EDIT : You're right - NAV ADR DISAGREE came sometime around 02:12:44 - so it must have been an ADR FAULT triggering ALTERNATE 2. Nevertheless, the PNF seems to have been aware that pulling up was not the correct response...]

Last edited by DozyWannabe; 14th Sep 2012 at 01:03.
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Old 14th Sep 2012, 02:47
  #377 (permalink)  
 
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gums, " But the nugget kept pulling, maybe believing that HAL would prevent a stall AoA."

Is there another way to see it?

The report is cherry picked sufficient to lend it to simplistic statements such as this. Gums, "nugget" is not a terribly professional term...

Dozy, this flight path went South in the first 20 seconds, tops. That is 2:10:25.
Speeds were acknowledged as duff at 2:10:16, and (generic) Alternate Law six seconds later, at 2:10:22. Not AL2.

PNF quickly stopped correcting PF, and ended up confused, telling Captain "We have tried everything, what do we do?"

Failing a complete CVR, and the true "nuggets", BEA has not made a case for a more complete picture.

I do not trust that BEA have redacted only irrelevant commentary and audio signals from the CVR for the public record....

That is not a widespread belief, but it is mine.

regards
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Old 14th Sep 2012, 02:59
  #378 (permalink)  
 
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Originally Posted by DW
so it must have been an ADR FAULT triggering ALTERNATE 2
No ADR FAULT.
The speed fall by ADR 2 and 1 were enough to disconnect the AP and cause the transition to ALT LAW but why the system is not telling the crew the reason for which it takes these steps ?
NAV IAS DISCREPANCY or SUDDEN CHANGE or UAS ...
This could be a serious help to the crew to understand what's happening and switch to the appropriate procedure.

I have not read the BEA mentioning the NAV IAS DISCREPANCY ecam msg ... did I miss it ?
Was it available on F-GZCP ?
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Old 14th Sep 2012, 03:08
  #379 (permalink)  
 
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What could possibly have caused the a/c to be unable to hold a heading? I think there was a reason for the NAV glitch.

Ref: BEA trace of leaky turn to starboard....

Last edited by Lyman; 14th Sep 2012 at 03:10.
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Old 14th Sep 2012, 10:22
  #380 (permalink)  
 
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Cool

Hi,

DW
It's possible that the PF either never heard or failed to understand the consequences of the PNF's "Alternate Law" call, but the idea that the PF believed the hard protections were still active can never be anything more than speculation.
This speculation seems to still be the most plausible
In fact it is supported by the fact that the pilot continues pulling on the stick despite the stall alarm and the remarks of the PNF
More .. the PF never acknowledge verbally the PNF "Alternate law"
A "normal" pilot (pilot knowing the Airbus flight laws) can do this if it has (or thinks) the protection in force

Last edited by jcjeant; 14th Sep 2012 at 10:27.
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