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AF447 wreckage found

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AF447 wreckage found

Old 7th Aug 2011, 12:08
  #2701 (permalink)  
 
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@ CONF iture
Well who cares what I'm doing for a leaving. I know that the purpose of such function is not aimed at controling PF imputs. But, as both stick imputs are already linked to PFDs, it would be no big deal, if such was really asked and needed by customers, to modify it for cross checking pilot imputs (and I seem to remember that we already had such a discussion about two years ago).
Even adding some feedback thru electrical commands would not add tons of hardware (weight) nor tremendeous development costs to the manufacturer. The very same could be say about "non-moving" lever thrust, silent autotrim, etc.

On the other hand, you just hate this brand, whatever their reasons being to do it like that. I can't remember a single feature you actually liked about an aircraft you are supposed to fly. On my side, I'd like to know why is your grief so deep? Personnal vendetta?
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Old 7th Aug 2011, 12:30
  #2702 (permalink)  
 
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Hi Greybeard,
Originally Posted by Graybeard
How much of the PNF attention was on the ECAM and not on the PF joystick actions?
It seems that there was not a single ECAM TB sequence popping up before 2 minutes after UAS, hence 1 minute+ into the full stall developement (0212+); the only one showing up, quite late, was ADR DISAGREE; there is barely no call about a procedure performed by him, either...
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Old 7th Aug 2011, 12:50
  #2703 (permalink)  
 
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re #2697

Hi takata,
no big deal but just to make it clear:

Sidestick
Hi Bubbers44,
Quote:
Originally Posted by Blujet
The post you are referring to was not issued by myself.

Thank you for your valuable infos on the VSI!! I checked 34-14-00ff but somehow missed this.
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Old 7th Aug 2011, 13:21
  #2704 (permalink)  
 
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Graybeard -
I've seen that so many times on these pages in defense of AB, in effort to end a line of thinking. How about considering the design is just plain defective?
How much of the PNF attention was on the ECAM and not on the PF joystick actions? In a yoke airplane, PNF would have been aware of PF actions at all times. Same goes for stationary throttles.
AMEN to ALL of that, Brother. But, you'll NEVER get the AB supporters to agree, unfortunately.
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Old 7th Aug 2011, 13:27
  #2705 (permalink)  
RWA
 
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Quoting bubbers44:-

"One thing that is puzzling me is the speed of PF's hand on his movements aft and forward on the sidestick.
From 02:10:13 to 02:10:16 (only three seconds) he moved his sidestick 9 times. That's three times a second..."
I think this may well be a matter of 'super-sensitive' recording, rather than anything more sinister. If you ignore the 'snaking lines,' and just count the basic 'ups and downs,' rather than the 'zigzags,' there appear to have been only about four of each in the period referred to. And we have to remember that the PF had just taken control after the autos signed off - according to the Report, his main concern at that time was to correct a tendency to roll. He'd have been mainly concerned with moving the stick sideways, not forward or back; if he'd moved it even slightly forward or back during the sideways movements (and assuming, as one has to, that the systems were probably recording in fractions of a second) it was probably 'no big deal.'

Looking again at Page 111, though, I noticed another thing. Assuming that I've interpreted the graphs correctly, while the THS was still moving towards 'full-up,' the PF applied full nosedown for quite a long period; probably because, as the report says, he was (correctly) countering the zoom climb. But the THS just continued on it's 'merry' way to full up.

What's more, if you look lower down, the Angle of Attack graph starts increasing at exactly the same time that the THS starts moving, at what looks like an exactly-equal angle (though opposite on the graph). And reaches its highest angle just as the THS arrives at 'full up'?

So (assuming I've read the graphs right) why didn't the THS react to the PF's apparently 'solid' nosedown input and 'get sensible'?
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Old 7th Aug 2011, 13:59
  #2706 (permalink)  
 
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Hello Mimpe
The AF 447 situation strikes me as one in which the incipient risks required the most experienced hand flyer right from the word go...no time for liberte,egalite,fraternite.....
Your numbers are very interesting.
But is it really a question of experience or is there more about this?
If its is only experience than this should be a constant about the history of aviation.

If its not a constant than there might be other factors like for example changed traning involved.
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Old 7th Aug 2011, 15:05
  #2707 (permalink)  
 
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Originally Posted by Graybeard View Post
I've seen that so many times on these pages in defense of AB, in effort to end a line of thinking. How about considering the design is just plain defective?
The "Airplane with HAL" :

Number of A330s built : 802
Number of A330 hull losses : 6

Percentage lost : 0.75%

The "Old-fashioned pilot's aircraft" :

Number of DC-10s built : 386
Number of DC-10 hull losses : 31

Percentage lost : 8%

You were saying?
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Old 7th Aug 2011, 15:16
  #2708 (permalink)  
 
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How about a boeing?

Do most of you agree that a boeing aircraft faced with the same conditions and failure would have clearly handled the problem and not ended up in the drink?
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Old 7th Aug 2011, 15:28
  #2709 (permalink)  
 
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YES.....Douglas also.
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Old 7th Aug 2011, 15:32
  #2710 (permalink)  
 
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@Petercwelch - I don't think that's a fair question. Going purely on statistics there have been two Boeing airliners (both 757s) that have ended up in the drink due to unreliable air data causing pilots to mishandle the aircraft, whereas to date it has only happened with one Airbus.

The issue at hand is whether the cockpit environment on older airliners is more conducive to help the pilots understand the problem (overcontrol -> stall -> loss of control). Some on here are adamant that it would be the case, others are not so sure.

3 pilots, 6 opinions and all that...

@DC-ATE - you could crash a DC-8 on approach by pulling a single lever too early ("It is forbidden to crash this airplane"). You could disable the takeoff trim warning on a DC-9 just by pulling a single circuit breaker that connected to a bunch of other systems, some of which were on the MEL. You could crash a DC-10 by not closing the door properly, and the door latch design itself would have caused Rube Goldberg (or Heath Robinson to us Brits) to wince. In the latter case, Douglas effectively bribed the FAA to not release that information while promising to fix the problem - they didn't fix it properly and nearly three hundred people died. Don't talk to me about Long Beach's supposedly superior engineering skills - they were riding the coattails of the DC-3's popularity and producing shoddy designs right up until they closed their doors.
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Old 7th Aug 2011, 15:54
  #2711 (permalink)  
 
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Well.....when I wrote Douglas, I guess I shudda specified DC-8. Never flew the other ones. Didn't like 'em. As to that "lever", it only happened once [which is enough] then everyone knew 'bout it and it never happened again. Give me a yoke any day, not one of these stupid SS controlers.
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Old 7th Aug 2011, 16:32
  #2712 (permalink)  
 
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But, you'll NEVER get the AB supporters to agree, unfortunately
It isn't about "AB supporters" or AB detractors - accident investigation should be an objective examination of the facts leading to a determination of the probable cause and making recommendations to improve what went wrong, no matter who manufactured the aircaft, who owned it, and who was flying it.
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Old 7th Aug 2011, 16:32
  #2713 (permalink)  
 
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Hi BluJet,
Originally Posted by BluJet
The post you are referring to was not issued by myself.
Arf!
Sorry for that! (I'm getting lazy at recycling old notepad templates)
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Old 7th Aug 2011, 16:57
  #2714 (permalink)  
 
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Petercwelch, #2712,
Your question assumes that the manufacturing design was the primary (dominant) or the only cause. It’s generally accepted that accidents are the culmination of many factors, requiring the interaction of significant issues.
Accidents arise from the unforeseen and often unforeseeable concatenation (linking) of diverse events, each one necessary, but singularly insufficient. J Reason.
A significant issue in this accident appears to be human behaviour; the crew’s perception and choice of action. Unfortunately we are unable to establish all of the facts of these matters. In our speculation we are exposed to hindsight bias due to the nature and timing of available information.

Some may argue that the Airbus FBW control system design degrades awareness, but the system is used without mishap in everyday operations by Airbus crews.
Have they adapted, have alternative control skills, or use other aspects for awareness? What are these features; were they absent in this accident or did the crew fail to use them? These have yet to be established.
The design of the stall warning system might be similarly cited, but other aircraft, although not engineered in the same way, have similar systems and meet the same requirements – including preventing unwanted warnings in other areas of the flight envelope, e.g. use system inhibits.

A more plausible view is that none of the crew identified the stall condition; again an aspect of awareness, and also, if the all speed displays are unavailable, an aspect which does not appear to differ with aircraft type.
If as suggested in the report, the PF had a mental goal of achieving an erroneous pitch attitude – that required for flight without airspeed, but which did not apply at high altitude, this also is invariant with aircraft type.
Conversely it is arguable that the resultant stall condition could have been recovered with a stick-push system, as fitted to many aircraft – noting that a controlled flight manoeuvre into the stall (as with AF447) would provide similar trim conditions irrespective of aircraft type. But again we can only speculate how the crew might have reacted to a stick push with regard to their mental model of the situation. We would hope that a forced stall recovery would ‘jolt’ the mindset, but evidence from other accidents (Colgan) suggests otherwise.

Many safety activities depend on asking questions, but the key issue is to ask the right question because in most cases, then the answer is obvious.
This accident has posed many questions and the industry is having difficulty in identifying ‘the right one’. This will not involve the aircraft type alone, but include the limits of human performance, the operational situation, organisation, and the system at larger in which we live; it will involve what we do and encounter every day, and how we do it.
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Old 7th Aug 2011, 17:18
  #2715 (permalink)  
 
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while the THS was still moving towards 'full-up,' the PF applied full nosedown for quite a long period; probably because, as the report says, he was (correctly) countering the zoom climb. But the THS just continued on it's 'merry' way to full up
Where do you see any evidence of "full nosedown for quite a long period"?

During the transition of the THS there are only a few intermittent nose-down spikes - the trace below the zero line means the stick was held back, pitching up.

Check the elevator trace on the same page: once the THS is on its "merry way to full up", at no time is the elevator pushed to pitch down. Not even close. The best it gets is about 15deg, pitch up. No wonder the THS never came back.
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Old 7th Aug 2011, 18:39
  #2716 (permalink)  
 
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Be very careful with stats especially when comparing apples with oranges.
How many total flight hours were they flown?
What type of flights (any military to theater of operations).
Have you corrected for tech advances - it would be better picking a contemporary of A330.
That said I do believe airbus are in general very safe, sadly the same cannot be said of humans.

Originally Posted by Dozy
The "Airplane with HAL" :

Number of A330s built : 802
Number of A330 hull losses : 6

Percentage lost : 0.75%

The "Old-fashioned pilot's aircraft" :

Number of DC-10s built : 386
Number of DC-10 hull losses : 31

Percentage lost : 8%
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Old 7th Aug 2011, 18:55
  #2717 (permalink)  
 
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Have you corrected for tech advances - it would be better picking a contemporary of A330.
The correct comparison is A330 vs. B777. All the numbers are from Wikipedia, I have not checked them myself but expect them to be reasonably correct.

A330:
Produced 1993–present
Number built 796 as of 30 June 2011
As of June 2011, the Airbus A330 had been involved in thirteen major incidents, including six confirmed hull-loss accidents and two hijackings, for a total of 338 fatalities.

B777:
Produced 1993–present
Number built 923 as of March 2011
As of April 2011, the 777 has been in seven incidents, including one hull-loss accident, and two hijackings, with no fatalities among the passengers or crew.

Any questions still remaining?
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Old 7th Aug 2011, 19:15
  #2718 (permalink)  
 
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I think there is very little to be gained by such "comparisons". "margin for Error" has more to say than raw numbers, and it always gets doen to subjective hoorah. both capable ships, and 447 has more to teach us that is real, and precious than fanbase. In a wide field of Gold, the nuggets are gathered early, and eventually, the safety is found in mining.
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Old 7th Aug 2011, 19:30
  #2719 (permalink)  
 
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Dozy;

Not wishing to sound facetious, but would you care to provide examples of where this has been the case any later than, say, 1994 (when the death of senior test pilot Nick Warner on a demonstration flight caused them to re-examine their priorites)?
Sadly unfortunate the example you quote, because it should be a warning to us all. This happened to a very experienced test pilot, at the end of a very busy day. Basic mistakes were made; if it could catch him out, then God help the rest of us. (Don't have the link to the report, but am sure somebody will provide it).

Re; software/hardware anomalies, a few come to mind-(Indian Airlines A320 open descent into ground at (Bangalore); Air Inter A 320 VS/FPA confusion and subsequent descent into ground -already mentioned;(Austria?); Air France A320 low flypast into trees (Paris?); Air Transat 330 fuel leak/crossfeed mishandling anomaly with glide landing into (Azores).

Don't get me wrong; as stated earlier, I am not bashing Airbus; some of these accidents were in the early days of FBW of which Airbus were the pioneers, and good on them. They are truly innovators. But there is no denying that their systems are not easy to understand, and they did make changes after each of these accidents. But then so did Boeing, and they have been in the business a lot longer.
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Old 7th Aug 2011, 20:14
  #2720 (permalink)  
 
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@xcitation : I'm stepping back for a bit, but quickly in answer to your question - I'm well aware of "lies, damned lies and statistics", and was just trying to illustrate the point that "the good old days" weren't all that good in some respects

@ap07, I'm not interested in Airbus vs. Boeing discussions - I was simply trying to prove the adage that things have gotten safer thanks to advances made by Airbus, Boeing and *all* manufacturers. Although it's worth noting that of the six A330 hull losses, 2 were due to military action and one was due to a cargo-handling accident. Of the three that were related to flight, one was the infamous test flight, another was the Libyan A330 which so far has no technical cause and the third is AF447.

In any case these statistics are too small to make a valid comparision, mercifully.

@Phantom Driver, the Indian incident, Air Inter and Nick Warner's A330 crash were largely put down to mode confusion, which has since been rectified. Air Transat was down to a maintenance issue IIRC and Habsheim (the A320 lumberjack) is a whole other story, which largely comes down to atrocious preparation on the part of AF, followed by a sequence of bad judgement calls made by the captain. Of these, only Air Transat happened after 1994.

@SLFinAZ below : How have "'A' ... also single handedly pushed the average pilot skill level significantly lower"? I'm all ears. Glass cockpits and full-featured FMS autopilots were pioneered by the A300, but enthusiastically picked up by Boeing with the 757 and 767, and Douglas with the MD-11. "What's it doing now?" has never related to FBW, but to the FMS/FMC/autopilot (call it what you will), which were well-established for more than a decade before the A320 first flew. And as for in-flight hull-loss stats, A330 vs B777 is currently 3:1 (not 0, as you stated), but again these numbers are too small to make a statistical comparison.

Last edited by DozyWannabe; 7th Aug 2011 at 20:52.
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