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AF 447 Search to resume (part2)

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AF 447 Search to resume (part2)

Old 16th May 2011, 07:14
  #1441 (permalink)  
 
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In fact, beside suspecting that ice crystals at cruise level could have been much more a factor than computers, I'm still clueless about how she finally ended like that.
For a number of reasons, I suspect you are right. For one thing, you would have to assume that AF/AB/BEA knew a lot more about AF447 from the outset than they ever released. They were pretty quick to take action about the pitot tubes. Conspiracy theories aside, they can't afford a repeat and so you would have to think that any initial measures they took would have been directed at what they believed to be the cause. There are also striking similarities between what possibly happened here, and other presumed icing incidents (including the ATSB report that sensor_validation mentioned).

One problem we are having is how the aircraft shed so much energy (kinetic and potential) and covered so little distance from LKP. This has caused many of us to speculate about a reversal of course at some point. Another explanation may be that the aircraft had a lower total energy at LKP than we have assumed. Kinetic energy must be about right - as I recall its speed was pretty much constant between points. But what about the potential energy.

I wonder what time problems started. Am I correct in understanding that LKP included position but not altitude? If so, could blockage of the pitot drain holes (rather than the tubes per se) cause an overspeed and hence a reduction in thrust? Could the aircraft have been losing altitude for some time before things obviously went wrong? An involuntary descent into a cb cell at night. At some point a drain hole unfroze, then unreliable airspeed......

I guess it is unlikely that multiple drain holes would ice up simultaneously however. Lots of other things seem not to fit with this scenario. If not already there, you would imagine that something like this would get the Captain upfront. Plus you might also at least secure the cabin.

I am sure plenty here will point out other problems with this scenario. Just trying to make order out of insufficient facts.
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Old 16th May 2011, 07:52
  #1442 (permalink)  
 
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Hi Bear,
Originally Posted by Bearfoil
Forensically, the lack of damage due forward acceleration is hidden (prevented) by a superior vertical number, yes?
Without a close examination of the wreckage, even if it is not lying far from home, I'm reduced to guess that it may be. Also, that parts of the forward fuselage (cockpit) and engines could have absorbed much more "forward" brutal acceleration than most recovered floating parts. It seems also pictured by the cabin fragmentation and the wreckage mix in the sea bed. Of course, also, I can be totally wrong.
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Old 16th May 2011, 07:58
  #1443 (permalink)  

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I had acquired the impression that all three flight officers aboard AF447 were fully qualified for the left hand seat of an A330-200.
No. Only captains and pilots on their command course qualify for the left-hand seat.
If it is the case your junior/senior distinctions don't quite fit AF447.
I'm afraid it does. The F/O elected by the captain as the pilot-in-charge - and the captain would be a fool not to choose the most senior one - occupies the RHS. The junior one ,the LHS;
That system, which is rather common with quite a few airlines has a few pernicious aspects :

1/- The PF /PM system is severely disrupted : the PM is not able to offer the optimum aid as every system is - from his new position - reversed, and it's not easy to operate switches that are not in the positions one is familiar with. Even more so in the dark or in periods of heavy stress.

2/- Supposing - it's a speculation - that the RHS has lost his flight instruments, the only available pilot is the least experienced one, operating with controls he's not used to...

Furthermore the senior most crew member was not the man in charge.
That happens a lot more often than you'd apparently think.
But it doesn't matter, the one in charge has four bars on his/her shoulders and expects loyalty from his/her crew.
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Old 16th May 2011, 08:29
  #1444 (permalink)  
 
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Musical Chairs

In Lemurian's scenario of 'Senior F/O returns to RHS, Junior switches RHS to LHS, Captain vacates', how is it done at a practical level?
At some point there is only one strapped in, but if there is no turbulence, is there any chance that there are none actually strapped in when the Sxxx hit the fan?

If there was just one, what are the chances of a second getting back into a seat and could a single pilot manage the sort of scenarios that have been suggested?

Last edited by paull; 16th May 2011 at 08:36. Reason: Clarity
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Old 16th May 2011, 08:59
  #1445 (permalink)  
 
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Originally Posted by Paull
In Lemurian's scenario of 'Senior F/O returns to RHS, Junior switches RHS to LHS, Captain vacates', how is it done at a practical level?
At some point there is only one strapped in, but if there is no turbulence, is there any chance that there are none actually strapped in when the Sxxx hit the fan?
It is assumed that the 1st FO was already in the RHS and the captain in his LHS before the arrival of relief pilot. Then, captain rest. This 2nd FO would take the captain's place (LHS), but now the Pilot Flying would become the 1st FO from the RHS (not optimum).
That is what I understand from Lemurian "musical chair" ballet.
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Old 16th May 2011, 09:31
  #1446 (permalink)  

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Takata :
That is what I understand from Lemurian "musical chair" ballet.
Or
- the junior F/O was on the RHS and the senior one comes from his rest -->
- Senior F/O takes over RHS
- junior F/O takes over LHS from the captain.

now the Pilot Flying would become the 1st FO from the RHS (not optimum).
This is ok as he's occupying a seat he's used to.
What is not optimum will be the assistance he'd expect from the LHS as all abnormal / emergency procedures require one pilot assuming piloting and communication functions and in our case, that falls on the guy on the RHS, and ther other one operating the systems to deal with the checklist, again from a position he's not used to.

Whatever happened during the first period, at the moment of the first ACARS transmission, we can say with quasi total certainty that the two F/Os were in charge of the airplane, the least experienced one on the LHS...( and that in the most ideal conditions... )

What is quite apparent to me in these instants just preceding the accident is the feeling of a *routine* atmosphere :
- normal OPS, crew not concerned with weather
- as too many passengers were found outside the plane, seat belts signs were not on
- captain ready to take his rest ( in the middle of the ITCZ, that's a sign of confidence in his crew and the weather that I have'nt shown in all my career !)
A picture that drastically changed in the following minutes, as they were just four minutes before the end.
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Old 16th May 2011, 09:47
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All change

In the case where the senior F/O is returning from his break then we have the case where no-one stays in a seat as I read it, clockwise from LHS seat reads: Capt, Junior, (Senior-standing) to be changed to Junior, Senior, (Captain-standing)

There again, there are far simpler examples of only one pilot in the cockpit. I just wondered, in an upset what is the chance of getting back into a seat or even getting back into the cockpit?

(Crossed in the post, thanks Lemurian)

Last edited by paull; 16th May 2011 at 09:49. Reason: Lemurian beat me to it
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Old 16th May 2011, 10:13
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Are we expecting any announcements from the BEA today with regard to progress in reading the data recorders?
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Old 16th May 2011, 10:58
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But over the weekend, some air-safety experts close to the investigation advised colleagues that the recorders, which were dried out in special ovens, seemed undamaged and ready for attempts to download data.
Reading the digital recorders was believed to pose unprecedented challenges because no such devices have been recovered after spending such a long time at such depths.


Air France Black Box Components Appear Undamaged - WSJ.com
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Old 16th May 2011, 11:21
  #1450 (permalink)  

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Stop press stop press

Latest !
France info scoop.
"The BEA announces that the totality of the recorded data on the black boxes has been extracted"
totality = everything, entirety... they've done it !
They've also said that an interim report will be publishjed *this summer*

Edit : Le Monde has this banner, which confirms my post :
12h20 Le BEA a pu lire toutes les données des boîtes noires du vol Rio-Paris
Le Bureau d'enquêtes et d'analyses est parvenu ce week-end à "recueillir l'intégralité des données contenues" dans les deux boîtes noires du vol AF-447, dont le crash avait fait 228 morts le 1er juin 2009. Le BEA annonce qu'un rapport d'étape sera rendu public cet été. (AFP et Reuters.)

Last edited by Lemurian; 16th May 2011 at 11:36.
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Old 16th May 2011, 11:22
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"Black boxes" read

according to french newspaper Le Figaro BEA was able to read all the datas contained in the so called black boxes over the wek end.
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Old 16th May 2011, 11:29
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The same news, for non-subscribers:

Air France KLM SA - WSJ: Black Box Components From Air France Wreckage Appear Undamaged - Sources
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Old 16th May 2011, 11:36
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That's good news about the recorders!
A couple of questions that I haven't seen addressed:
1. Does the damage to the engines indicate that they were running at impact?
2. A friend has an iPhone App that tells him the windspeed when he holds the phone up in the wind.
I don't know how it would work for flying speeds. but it seems fairly accurate in lowish winds.
Could this technology be applied to aircraft even as a separate system?
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Old 16th May 2011, 11:38
  #1454 (permalink)  

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1. Does the damage to the engines indicate that they were running at impact?
Apparently yes.
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Old 16th May 2011, 11:39
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Black boxes

The BEA could read all the data of the black boxes of the flight Rio-Paris
The Office of investigations and analyses managed this weekend “to collect the entirety of the data contained” in the two black boxes of the flight AF-447, whose crash landing had caused 228 deaths on June 1st, 2009. The BEA announces that a report of stage will be made public this summer. (AFP and Reuters.)
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Old 16th May 2011, 11:49
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Breaking News at CNN :

Flight recorders from Air France 447 found in Atlantic Ocean are readable, French air accident investigators say.
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Old 16th May 2011, 11:59
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BEA communiqué, 16 mai

16 May 2011 briefing

Following operations to open, extract, clean and dry the memory cards from the flight recorders, BEA Safety Investigators were able to download the data over the weekend.These operations were filmed and recorded in their entirety. This was done in the presence of two German investigators from BFU, an American investigator from NTSB, two British investigators from AAIB and two Brazilian investigators from CENIPA, as well as an officer from the French judicial police and a court expert.
These downloads gathered all of the data from the Flight Data recorder (FDR), as well as the whole recording of the last two hours of the flight from the Cockpit Voice Recorder (CVR).
In the framework of the safety investigation directed by the BEA, all of this data will now be subjected to detailed in-depth analysis.
This work will take several weeks, after which a further interim report will be written and then published during the summer.
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Old 16th May 2011, 12:01
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takata, do you consider the "fourth occupant seat" that was recovered to be the second of two jump seats in the cockpit?
______________

Not that we may ever be told, but it might prove an interesting contrast to compare the behavior of the crew of AF459 that followed the track of AF447 into the ITCZ. AF459 would have had similar SIGMET information, and presumably received a text alert from dispatch similar to that sent to AF447 regarding convection as seen on satellite between SALPU and TASIL. Did that crew also go to SELCAL mode, and begin a rest rotation? Perhaps not.

From the first interim report, it seems AF450 were on alert after unexpectedly encountering turbulence near NATAL. AF459 also perhaps heard conversation between ATLANTICO and IB 6024 flying ahead on its deviation to the east by 30 NM. And perhaps both AF459 and IB6024 overhead communications between ATLANTICO and LH 507 on its deviation to the west after passing ORARO.

Flight AF459 (Airbus A330-203) passed at the level of the ORARO waypoint approximately 37 minutes after l’AF447. The sky was clear but the half-moon, visible to the aft left of the aircraft, did not make it possible to see the contour of the cloud mass distinctly. After flying through a turbulent zone in the head of a cumulus congestus formation at the level of NATAL, without having detected this zone on the radar, he selected gain in MAX mode. At about 2 h 00, he observed a first echo that differed significantly depending on whether the radar’s gain was in CAL or MAX mode. The TILT was set between -1° and 1.5°. He decided to take evasive action to the
west, which resulted in a deviation of 20 NM to the left of the route. During this evasive action, a vast squall line with an estimated length of 150 NM appeared on the screen, which was set to a scale of 160 NM. The echoes were yellow and red when the radar was set with gain on the MAX position and green and yellow when the gain was on the CAL position. No lightning was observed.

ATLANTICO control, informed by the crew of their decision to avoid this squall line by taking evasive action to the east, asked them to return to the airway as soon as they could. This evasive action meant the aircraft flew between 70 and 80 NM to the right of the planned route. In addition, the crew was authorized to climb from FL350 to FL370.
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Old 16th May 2011, 12:15
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Chris Scott By the way, I think the canisters shown in the pictures are in the bottom of the stowage unit, so the part that the diver is standing in is the top.
no chris, (even this message will fast go under, like a engine falling throug water, into the troubble of the great message abaut the readable recorders....) the diver stands under the table, in the area the lost trolly-containers are normaly parked, you see the botton demage of the honycomb struktur, the boxes are on top
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Old 16th May 2011, 12:17
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The fourth occupant seat is indeed the second jump seat and is situated behind the copilot's seat.On my company 330 fleet the third occupant seat is situated behind the centre console and is a more substantial design than the fourth occupant seat.
The pilots seats are handed ,i.e they have the substantial arm rest on their outboard and the seat controls inboard.If an occupant was discovered still attached to a seat it should be fairly straight forward to see who was sitting where
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