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AF447 Thread No. 3

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AF447 Thread No. 3

Old 6th Jun 2011, 01:22
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It's clear what happened

No one understands where the border between man and machine lies, man has become a kiss-up to machine in order to have a job, machine is just doing what it's told by people who do not actually ever fly, are always at V-underscore-office-chair.
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Old 6th Jun 2011, 01:49
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Thinking back to the Airbus flight demos of the A-300 FBW prototype at Paris and Farnborough in the late 1970's or early 80's, when Bernard Ziegler (or was it Pierre Baud?) made a great display of the 'impossibility' of stalling the machine, by holding the stick fully aft as it waffled down the flightline at minimum IAS 'bobbing' like a porpoise, how much in the way of actual stalls did they do on the A-320/340/330 during the development/certification process?

Did Airbus evaluate the handling characteristics in fully developed stalls (presumably in Alternate Law) to confirm the fully developed stalls in all configurations were actually compliant with JAR/FAR25, with or without stall protection? Or, would they have been permitted to by-pass some, or all of this time consuming requirement, as it could be considered a redundant exercise with a functioning stall barrier?
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Old 6th Jun 2011, 02:31
  #1443 (permalink)  
 
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It's clear....

Thank you, desitter.

I have seen some members here with an almost childlike faith in the sfwe and control logic.

From an old, grizzled pilot that flew the very first fully FBW system in a design that was statically unstable below 0.91 M, and had to deal with the computer logic and such, I am becoming deeply concerned.

- loss of basic airmanship
- confusing warning display chirps, flashing lights, changes in the basic displays, reversion to "laws" after "laws".

We old dinosaurs were very concerned about the raw nuggets that came to us. They were the Atari generation, and adapted to the computers easily. We were concerned that they would lose their basic pilot skills because the jet was so easy to fly at the edge of the envelope. So we kept harping upon basic aero principles and showing how the jet WOULD NOT PROTECT YOU ALL THE TIME!!! Gasp! Beam me up!

I do not see this with our current crop of heavy pilots, and it scares the hell outta me.

Trust me, a completely FBW system is not a simple electric connection to the control surfaces. Even the Airbus reversion modes are using yaw, pitch and roll inoputs to limit the control surfaces. And they should in most cases.

What I don't see is a simple reversion sequence and the use of "standby gains" for aero data that is determined BY THE COMPUTERS to be unreliable.
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Old 6th Jun 2011, 02:42
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Wasn't the Flight Test A330 that crashed due to a stall? I remember something about no stall protection in Altitude Capture mode.

When was the last time Boeing or Douglas lost a plane in Flight Test?
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Old 6th Jun 2011, 02:44
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Turbine D

Take a look at this presentation by Boeing and tell me what you think.

http://icingalliance.org/meetings/RI...ersion_nss.pdf
Good summary it matches my thinking
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Old 6th Jun 2011, 03:06
  #1446 (permalink)  
 
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Lets think about it a different way. It has leaked that the aircraft never achieved the abnormal attitudel law. For this to happen, It would seem that there was no synchronization of two airspeeds to form a "consensus" after the initial switch to ALT2 law.
Thinking about it differently is that that 'leak' was a direct response to the discussion on Abnormal Attitude Law in this thread. i don'k understand why the BEA report appears to present many gaps in the information, an ambiguous cronology and that some of the details are glossed over. Does this mean that. transparent investigation is unlikely.
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Old 6th Jun 2011, 03:38
  #1447 (permalink)  
 
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Sciolistes
Thinking about it differently is that that 'leak' was a direct response to the discussion on Abnormal Attitude Law in this thread. i don'k understand why the BEA report appears to present many gaps in the information, an ambiguous cronology and that some of the details are glossed over. Does this mean that. transparent investigation is unlikely.
For whatever reason the "leak" occurred, it helped clarify the direction that the discussion needed to progress. To me, it was a kindness that a busy group of people (BEA) let slip into the media to keep us duffers better up to speed and more realistic in our thought processes.

I can fully understanding that while they (BEA) are themselves debating the import of various pieces of data, they would not want to stop the process to battle rumors in the press. As discussed here previously, the examination of data and fitting it into a context of the event is rigorous.
Anyone who has done data reduction would know this inherently.
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Old 6th Jun 2011, 03:44
  #1448 (permalink)  
 
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For whatever reason the "leak" occurred, it helped clarify the direction that the discussion needed to progress.
I can understand that people want to discuss this, but this is an investigation and there is no right direction for the discussion other than that inferred by being in possession of all known data and information. The idea that it good of those nice busy BEA people to help us along is just nonesense.

It just isn't right to release a portion of the known story. I can understand an interim report so long as it states all what is known and the current threads of investigation. As they have the FDR and CVR, I believe, they should release nothing until such time as they can definitively state the cause or most probale cause as complete effort. Anything less appears to be playing the media.
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Old 6th Jun 2011, 04:29
  #1449 (permalink)  
 
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It just isn't right to release a portion of the known story.
Can you justify this attitude other than you wanting the whole report in your lap right now.
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Old 6th Jun 2011, 04:39
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Re: "Je ne comprends rien."

CONF iture:

Indeed the quote, "Je ne comprends rien," has come from multiple media sources, most of them French, and it has haunted me since I read it -- and I don't mean this in a sensational way. Simply that there is a responsibility to see that the causes of that confusion are addressed -- and perhaps there are issues which have just been carried on and been tolerated, like all the bells and whistles which make those moments even more difficult. (Though of course it is the substantive issues which were the cause of whatever confusion which are most important and clearly need to be addressed.)

Some articles quoting this:

In this story, it's the headline:
Vol Rio-Paris: "Je ne comprends rien", s'écrie l'un des pilotes | France Soir

In this one, it is also the headline and seems to be saying it is from the BEA report. See below.
Rio-Paris : "je ne comprends rien", aurait dit un pilote - France - TF1 News

"Rio-Paris : "je ne comprends rien", aurait dit un pilote

le 26 mai 2011 à 17h34, mis à jour le 26 mai 2011 à 22:54

Le Bureau d'Enquêtes et d'Analyses doit publier vendredi un document, tiré de l'analyse des boîtes noires du vol Rio-Paris. Il contiendrait notamment une partie de la conversation des pilotes, quelques minutes avant le crash.
Un des trois pilotes du vol Air France Rio-Paris aurait dit "je ne comprends rien" au moment de la perte de contrôle de l'A330, qui s'abîmera peu après dans l'Atlantique avec 228 personnes à bord, rapportait jeudi France Info s'appuyant sur une note des enquêteurs du BEA."

Basically it's saying that the BEA report contains a part of the conversation between the pilots, from the minutes before the crash. One of the three pilots on the Air France Rio-Paris flight said, "I don't understand anything" ....


Air France crash inquiry details pilots' battle for survival | World news | The Guardian

From the Guardian:
<<French air accident experts published a chilling chronology of events that showed the three Air France pilots battling to regain control on flight 447 from Rio de Janeiro to Paris in a heavy thunderstorm on the morning of 1 June 2009.

Air France acknowledged that the disaster was triggered by faulty speed sensors, with one of the pilots exclaiming "we have no valid indications" as the Airbus A330 fell at 10,000ft a minute. Moments before the crash, one of the pilots, again unnamed, reportedly shouted "Je ne comprends rien" ("I don't understand a thing").>>

Again in this France Soir article
Airbus, la descente infernale : Tout s

The quote is part of the timeline:

"2 h 11 min 45 s. Tandis que toutes les vitesses redeviennent invalides et que l’alarme de décrochage s’arrête, le commandant de rejoint les deux pilotes dans le cockpit. « Je ne comprends rien », lâche l’un d’entre eux, affirme sur France Info Michel Polaco, pilote instructeur et ancien patron de la station. L’avion tombe alors à grande vitesse et il n’est pas sûr que dans la nuit, en pleine turbulence et au milieu des alarmes, les pilotes s’en rendent compte tout de suite."
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Old 6th Jun 2011, 04:41
  #1451 (permalink)  
 
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Errm, yes. I don't want it right now. I want it right!
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Old 6th Jun 2011, 05:15
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Garrison I measured the ground distance along the flight path from point 6 to impact. (I did this on the assumption that the BEA graphics are computer-generated from GPS data and are therefore precise.)
I do not think there are GPS data on the FDR.... BEA has had generated (extrapolate) a flightpath between the LKP (GPS) and crashplace (water surface over engine place on ground) from all other FDP datas
(speed...course...altitude...time all compared with the accelerations x/y/z...)

but all in all, your average datas will be +/- correct,


I wish nice hollydays to all here, tree weeks no forum-obsession!
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Old 6th Jun 2011, 05:35
  #1453 (permalink)  
 
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Well, seems to me that when various facts of the case become public knowledge, it becomes very hard to doctor them to suit an agenda. The more in the public arena in the way of facts, the better. And we know they have the data, they have told us they do.

But they cannot give us half facts. That will cause mis-interpretation and cries of coverup when they do give us their interpretation. Whatever they give must be able to stand by itself.

And if the final interpretation of facts is open to question, you and I will be here to question them, won't we?

So they know they had better get things right the first time if they don't want to have egg on their face. And they know that they have to get the information out quickly but accurately in a manner that will cause the least confusion and doubt possible.

Personally, I would find the whole problem a tremendous headache. Let us just peacefully speculate on the limited data we have received, and wait relatively patiently to have our partial interpretations of the accident confirmed or refuted. Turmoil only has the potential to slow the investigation.
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Old 6th Jun 2011, 06:46
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Well, seems to me that when various facts of the case become public knowledge, it becomes very hard to doctor them to suit an agenda.
The only facts are those in the BEA report. But as those facts are deliberately incomplete then the incident can only comprehended through interpretation and that is not factual.
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Old 6th Jun 2011, 08:07
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Pilots released to fly

JD EE

ALLOW ME TO CLARIFY. RELEASED TO FLY FROM A MAJOR AIR CARRIER DOES NOT MEAN HIRED ON AS A NON-PILOT AND THEN BEGINNING TRAINING TO LEARN HOW TO BE A PILOT.
When I hired on with a major airline I had 10 years experience in the Air Force. 5 years flying high performance fighters and 4 years in transports.
A captain with a previous airline.
No matter. One still has to complete the airlines syllabus in their particular aircraft and position (co-pilot or engineer ).
Later as a flight instructor and FAA Check Airman I was responsible for certifying newly checked out Captains and Co-pilots for line flying.
When these "new" pilots were checked out and released, by the time they finished training and enroute flying performance - they were then "Released" for on-line flying. From day one: they were fully qualified to deal with any eventuality they would encounter in flight. They might be a bit slower, or more methodical, but they were fully as safe as any "old Pro".
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Old 6th Jun 2011, 09:24
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Graybeard:

On 30 June 1994, an A330 owned by Airbus on a test flight simulating an engine failure on climbout crashed shortly after takeoff from Toulouse, killing all seven on board.
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Old 6th Jun 2011, 11:38
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I bet Air France is a little concerned about that lack [of recording ARD2 data] and may become more so when the next report (months off?) comes out.
That lack is of course highly regrettable but I doubt AF has latitude to choose what is recorded, except on QAR.
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Old 6th Jun 2011, 12:05
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Flight Test Fail

Found it. Points that have received heavy discussion WRT AF447 in bold:

ASN Aircraft accident Airbus A330-321 F-WWKH Toulouse-Blagnac Airport (TLS)

...
The takeoff was performed by the co-pilot with TOGA (takeoff Go Around) power, instead of Flex 49 (a lower power setting). Rotation was positive and pitch input was stopped when the attitude changed from 12deg to 18deg nose-up. Within 5 seconds after takeoff several attempts to engage the autopilot were unsuccessful. After it was engaged, activation was delayed by 2 sec because the 1st officer was exerting a slight nose down input on the side stick. The aircraft, still trimmed at 2.2deg nose-up pitched up to reach 29deg and the speed had decreased to 145 knots. The captain meanwhile reduced thrust on the no. 1 engine to idle and cut off the hydraulic system in accordance with the flight test order. Immediately after it activated, the autopilot switched to altitude acquisition mode (altitude had been set at 2000 feet on the previous flight phase). This caused the pitch attitude to increase to 32deg in an attempt to reach 2000 feet. The speed decreased further to 100 knots (minimum control speed=118 kts). Roll control was lost and the captain reduced no. 2 engine thrust to idle to recover symmetry on the roll axis. Bank and pitch attitudes had reached 112deg left and -43deg resp. before the pilot managed to regain control. It was however too late to avoid ground impact at a pitch attitude of around -15deg.

PROBABLE CAUSES: "At the present stage of its work, the commission estimates that the accident can be explained by a combination of several factors none of which, taken separately, would have led to an accident.
The initial causes are primarily related to the type of the test and its execution by the crew during the last takeoff:
1) choice of maximum power (TOGA) instead of Flex 49;
2) very aft CG for the last takeoff;
3) trim set in the takeoff range, but in too high a nose-up position;
4) selected altitude of 2000 feet;
5) imprecise and late definition of the test to be conducted and the tasks to be performed by the captain and first officer, respectively;
6) positive and very rapid rotation executed by the first officer;
7) the captain was busy with the test operations to be performed immediately after take off (engagement of the autopilot, reduce thrust on the engine and cut off the blue hydraulic system) which temporarily placed him outside the control loop;
8) in addition the absence of pitch attitude protection in the autopilot altitude acquisition mode played a significant role.

The following is also contributed to the accident:
1) The inability of the crew to identify the mode in which the autopilot was placed;
2) the confidence of the crew in the expected reactions of the aircraft;
3) the late reaction from the flight test engineer when faced with a potentially hazardous change in parameters (speed in particular);
4) the time taken by the captain to react to an abnormal situation."
Note: the latest BEA report on 447 gave the CG at 29%, while earlier info reported 37%.
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Old 6th Jun 2011, 12:46
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Hi Mig15,

why wasn't the aircraft flown using "pitch & power" to recover after the initial upset
I don't know why the crew didn't lower the nose sufficiently when they first received the "stall stall" warning.

However, when the IAS fell below 60kts the stall warning ceased - they may have believed that they had successfully recovered from the stall. The Captain entered the flight deck to observe:
FL 350 descending; 10,000 ft per min rate of descent; TOGA power and pitch attitude about 15 degs nose up with NO Stall Warning, and probably advised by his FO's that they have had unreliable air speed indications.

They have 2 mins and counting to sort that one out before it's too late.

I think it's a pity that the PNF was unaware of the stick inputs being made by the PF (due AB design). If they had control sticks which moved in response to the the other stick input - maybe the PNF would have recognised the stick full back requests?

Didn't some people believe the Titanic was unsinkable, so they were allowed to place fewer life boats on board than the passenger capacity? Sounds a bit like the absence stall recovery advice in the QRH in 2009.
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Old 6th Jun 2011, 13:02
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@deSitter

You really are bitter, aren't you? What part of "pilots were in the loop during requirements gathering" are you failing to understand?

@gums

I have to say, I'm not seeing "childlike faith" in the software or protections. Everyone here is saying that training for failure modes (including law reversion) needs to happen. Loss of airmanship skills is a training issue that needs to be addressed.

Originally Posted by Graybeard
When was the last time Boeing or Douglas lost a plane in Flight Test?
Douglas effectively wrote off an MD-80 in flight testing (the infamous high VS landing that snapped the tail assembly off). Douglas also put an aircraft (DC-10) into service with a known design flaw that they discovered in testing and simply ignored in the rush to beat Lockheed to market - that little doozy killed over 200 people. Boeing had exactly the same problem should pitots be blocked on the 757.

All this US/Franco willy-waving gets us nowhere.
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