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AF447

Old 23rd Jun 2009, 19:30
  #2221 (permalink)  
 
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Take it from me. If they have a ping it won't take long to triangulate it. Now a very big ocean is much much smaller. My bet is recovery of the recorder(s) within 3 days.
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Old 23rd Jun 2009, 19:49
  #2222 (permalink)  
 
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Some very interesting new photos (once clicked on the images will open in a reduced size, click on again to see a very large version):







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Old 23rd Jun 2009, 20:06
  #2223 (permalink)  
 
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This: wreckage (bottom right) looks like it has part of a Business Class seat.
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Old 23rd Jun 2009, 20:07
  #2224 (permalink)  
 
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DB:

As usual, thanks for posting these pics. And thanks again for organising the album.

Though there isn't much we can conclude about what happened (yet), the more we see photos of items from the aircraft, the more we can posit what didn't happen.

Grizz
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Old 23rd Jun 2009, 21:04
  #2225 (permalink)  
 
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Searching the deep ocean

I have searched PPRuNe and cannot find any reference to this paper. It does seem that the search is not working, but maybe I am not driving it properly?

Blank Design page
DEEP OCEAN SEARCH PLANNING:
A CASE STUDY OF PROBLEM SOLVING
In late 1987 a Boeing 747 of South African Airways crashed into the Indian Ocean after an onboard fire.

Seems to me a but self congratulary but also seems to have a lot of good material. I read it a few days ago but the circumstances seem very similar to the AF447 and they found one of the recorder after about a year. I am not sure what the bottom was like but the depth was similar.
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Old 23rd Jun 2009, 21:19
  #2226 (permalink)  
 
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Graybeard

Post # 2243

My Friend, Precisely!! Some cannot see the forest for the trees. I think there will be a great deal of rethinking and redirecting of technology and resources after this accident gets sorted out. Training, pilot/box interface, newer com, tx, mx, wx, all of it. We got complacent and lost our way a bit.

Regards, Will
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Old 23rd Jun 2009, 21:24
  #2227 (permalink)  
 
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Thanks for the posted link jimjim1.

Just a couple of tidbits that jumped out at me...

The search for the wreckage was continued using side scan sonar, a system of using sound reflections to record the presence of objects on the sea bottom. To achieve this in the ocean depths in the accident area a cable of 9 kilometres long was required to tow the sonar near the ocean bottom. The equipment again is highly specialised and brought its own logistical problems. It was this equipment that located the sea bottom wreckage.
The conditions under which the search was conducted were beyond the designed situation for this type of search. The consequence was a large number of false alarms. Of the total number of pinger like sources that were recorded, 32 had to be considered, of which 13 could not be rejected as possible actual pingers.
They give you hope for even after the recorder pinger batteries fail, but also point out "false alarms" which were not something I had ever considered.

This was in 1987, I am hoping that the newer equipment for detecting the pings and advances in side scan sonar give the current searchers a bit more to work with.
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Old 23rd Jun 2009, 22:29
  #2228 (permalink)  
 
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For the region CSS Dakar/Senegal:

AFR 447 SAR OPERATIONS
END OF SAR OPERATIONS.

We inform you that we have stopped the search operations in our area. If you need supplementary means of assistant we could send you our research means.
We extend our great appreciations to all of you helpful support in fulfillment of our duties vis-à-vis the international SAR community.

Regards,
POUR LE COLONEL, CHEF D´ETAT-MAJOR DE L`ARMEE DE L`AIR ET DIRECTEUR DU CCS.

___________
FULL TEXT

23/06/2009 - Informações sobre as buscas do voo AF 447 da Air France - Nota nº 40

O Comando da Marinha e o Comando da Aeronáutica informam que, nesta terça-feira, dia 23, não foram avistados corpos na área de buscas, tendo havido apenas visualização de material diverso, de forma esparsa e em pequena quantidade.

O SALVAERO RECIFE recebeu hoje mensagem do Centre de Coordination de Sauvetage (CCS DAKAR/Senegal) informando sobre a suspensão em definitivo das atividades aéreas de busca sob coordenação daquele país.

O documento também destaca a ajuda prestada pelo Brasil, apoio esse fundamental para a comunidade internacional de busca e resgate.

Consequentemente, a partir de hoje, apenas aviões sob a coordenação do SALVAERO RECIFE permanecem nas buscas.

Leia, na íntegra, a mensagem do CCS DAKAR.

AFR 447 SAR OPERATIONS
END OF SAR OPERATIONS.
We inform you that we have stopped the search operations in our area. If you need supplementary means of assistant we could send you our research means.
We extend our great appreciations to all of you helpful support in fulfillment of our duties vis-à-vis the international SAR community.

Regards,
POUR LE COLONEL, CHEF D´ETAT-MAJOR DE L`ARMEE DE L`AIR ET DIRECTEUR DU CCS.


____________________________

I guess this graphic shows that region, seems kinda odd to me that they would stop searching in this region...considering the northerly current....



Last edited by DorianB; 23rd Jun 2009 at 22:50.
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Old 23rd Jun 2009, 22:35
  #2229 (permalink)  
 
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Looking for the boxes.
I asked a friend who does analysis for various people to look at the problem of how to find the boxes and received the following reply:

For these sorts of searches, the best possible search pattern is to just "mow the lawn." If that's the case then the probability of detection is just the ratio of the area searched to the area to be searched. Generally, though that estimate is excessively optimistic. In practice few searchers actually conform to that plan for a myriad of reasons. Generally what actually happens is that they just randomly churn around places they haven't looked before until finally they find something. Statistically, the worst you can do is just by random chance. Is given by the cumulative exponential distribution.

Pd = 1 - exp(2*R*v*t/A)

where

Pd = the probability of detection
R = is the sensor range
v = the searcher speed
t = search time
A = size of the area to be searched.
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Old 23rd Jun 2009, 23:16
  #2230 (permalink)  
 
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Good eye Kuningan - parts of 1st Class seats:

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Old 24th Jun 2009, 00:16
  #2231 (permalink)  
 
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Figures, now I find a pic that probably shows the large galley structure from the previous set of pics in the upper right hand corner.

Google Image Result for http://farm3.static.flickr.com/2184/2355546554_772bf0c5b7.jpg

Any idea if the large rectangular object in the new pics is the coat closet like area in the upper left of this pic?

The piece in the wreckage looks like it has ridges for holding something like trays that would be slid in, think refrigerator shelves, but with only a couple inches between them.

Last edited by ACLS65; 24th Jun 2009 at 01:05.
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Old 24th Jun 2009, 00:42
  #2232 (permalink)  
 
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ornis:

My post back at #2194 has a link to an interesting paper about the past and future of the recorders.
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Old 24th Jun 2009, 02:07
  #2233 (permalink)  
 
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ACARS

Eurocopit www.eurocockpit.com/images/PFR447.php has puplished updated and more complete ACARS messages:

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Old 24th Jun 2009, 02:14
  #2234 (permalink)  
 
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In the first two pictures there is a piece with a circular hole about 6" in diameter.

Could this be the inspection window in the cabin door?

YouTube - A330 Cabin Door
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Old 24th Jun 2009, 03:05
  #2235 (permalink)  
 
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A = size of the area to be searched.
The area in this case will be projected area of the underwater mountains, and will be greater than a planform area.

Can't visualize much success from the side scan sonar seeking objects. Side scan outlines shapes when looking for objects on a flat sea floor.
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Old 24th Jun 2009, 03:59
  #2236 (permalink)  
 
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Some Technical Clarification

No matter how much you computerize and automate and digitize via pressure-sensing transducers, the pneumatically derived values of pitot pressure (dynamic plus static) come from the same sources. However, courtesy of automation, the engineers are free to determine whether or not they should integrate the port and starboard digitized values and compute an ongoing average value or also incorporate (and integrate) the "pitot-derived static" in order to "iron out" the minor errors at different speeds and attitudes/altitudes related to the static sources (aka position error correction).

As you'll no doubt be aware, the source of the speed display on an ASI is the result of "balancing" (or deducting) the "static source derived" static pressure against that (perhaps slightly different) static pressure that's part of the dynamic input to the pitot heads. That's why, when water in static lines freezes, the ASI will wind back to zero in a climb. It only takes about 2000ft in a 210kt climb as the pitot-derived component of static is overcome by the much greater trapped static line pressure. I've seen that on a number of occasions due to aircraft being parked in rain without static port bungs in place and the "sucked in" rain-water freezing as you pass freezing level in the climb (altimeter stops, VSI reads zero). You're then in POWER + ATTITUDE = PERFORMANCE country. If you're feeling destructive, you can depressurize and smash the glass face of the VSI to get a source of unfrozen static pressure and restore speed display, altimeters and VSI.

When you take into account that there are at least two (sometimes three) pitot heads (e.g. the A330/A340) and multiple static ports, then the engineers are "spoilt for choice" when it comes to sourcing and integrating their data flows to the ADIRU's.

It's never done as simply as you may think. Keep in mind also that normally there will be little difference between port and starboard sources (airplanes being symmetric and normally flying symmetrically). However an inadvertent spin entry from a coffin corner loss of control situation may change that port/starboard equivalence in both pitot and static - and be capable of providing the sort of speed disagreements between ADIRU's that would generate the messages sent by ACARS in the final 4 minute plummet from altitude in a spin/spiral.

Hello,

I was reading your post

1582 and

noticed this term:

"pitot derived static"

Am I to understand that it is possible to extract static pressure from the pitot line?

I'm a curious glider pilot.

Cheers,
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Old 24th Jun 2009, 04:23
  #2237 (permalink)  
 
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May I suggest that general shortcomings and suggested improvements to the fright recorders be explored in Tech Log? They are less likely to be deleted there.

GB
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Old 24th Jun 2009, 04:40
  #2238 (permalink)  
 
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endless discussion of debris

You know it doesn't do much good to go on and on about every last piece of debris. There is a lot of good information that comes out of control surfaces and so on, in order to determine why the airplane quit flying. There is almost no good in debating all these smashed seats and entertainment systems and oxygen bottles and on and on. That kind of speculation is too near the experience of the dead to countenance.

-drl
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Old 24th Jun 2009, 04:47
  #2239 (permalink)  
 
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too near the experience of the dead to countenance.
Respect your compassion. Had a tough time reading about China 611 and infants still being clutched by mothers. Also respect the investigators that can sequester that to another part of their mind and inspect/dissect all the evidence so this particular fault won't readily happen again.
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Old 24th Jun 2009, 06:45
  #2240 (permalink)  
 
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ClippedCub:
Affirmative. Saying that damage, and the damage to a perceived forward door, might be too severe to think a forward galley would survive intact. Hard to say either way.
Actually this galley is from the business class, at left hand, boarding from door 2L. It is the only one in aircraft with 5 chariots. A good part of the wreckage identified is from this part of the aicraft.
See the post here:
http://www.pprune.org/rumours-news/3...ml#post5009874

ClippedCub:
However an inadvertent spin entry from a coffin corner loss of control situation may change that port/starboard equivalence in both pitot and static - and be capable of providing the sort of speed disagreements between ADIRU's that would generate the messages sent by ACARS in the final 4 minute plummet from altitude in a spin/spiral.
Posited that a few pages back. So far unchallenged.
Interesting explanation but, so far, about 35 other A330/340 pitots probe incidents occured (discounting AF447) as reported now, at cruise level, including 9 AF flights, most triggering the same sequence of ACARS and none were actually stalling/spinning but flying strait and level. So, obivously this theory is not only challenged but already debunked. This sequence is very well documented by Air Caraibes case and its obvious cause was probes freezing. If any stall/spin occured to AF447, it was after the probes problem, and wasn't the origin but could be the consequence.

S~
Olivier
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