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AF 447 Search to resume

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AF 447 Search to resume

Old 5th Apr 2011, 17:34
  #3041 (permalink)  
 
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Thank you BOAC

However,
I'd imagine that even if the tail and FDR would have fallen off in the air, the pieces would certainly not glide very far (meaning more than a mile or so from the main part).

Fingers crossed for next news...
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Old 5th Apr 2011, 17:42
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takata,

If they had maintained cruise altitude during that 4 -5 minute series of failures, and then had a simultaneous double-engine (and therefore double-generator) failure, they could indeed have glided for about 12 -15 minutes. Seems a bit odd that they should end up ditching without pre-warning cabin crew and passengers, and find themselves within about 15nm of where they were when their problems began.

Last edited by Chris Scott; 5th Apr 2011 at 18:03. Reason: Clarification of failure sequence
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Old 5th Apr 2011, 17:45
  #3043 (permalink)  
 
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Personally I suspect the tail section (and FDR) are sadly a long way away from this wreckage - I hope I am wrong
Good point for a little discussion to while away the boredom

Given that we accept a flat impact with the water (liitle roll or pitch) would that give a clue whether a tail (possibly with recorders) was still attached ?
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Old 5th Apr 2011, 18:04
  #3044 (permalink)  
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No, nothing to do with in-flight separation 'theories', but more to do with a heavy impact, surmised to be tail down. It is expecting a lot of a tailplane assembly in that situation not to cause tail section separation which leaves a light'ish structure to make its own way down to the sea bed, taking with it the FDR. No pinger any more - now find it?

As I say, I hope for all I am wrong. The sonar 'finding' so far has been brilliant. I hope it continues.
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Old 5th Apr 2011, 18:45
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BOAC, the distance between the location and the western boundary of the June 1 2009 search grid flown by Brazil is probably several nautical miles. If the VS came off simultaneous with the rest of the tail, I would think the VS would be hard to miss if the separation occurred within that first day's search area.

So I rather doubt that the tail is a long way off; however, it may be the most shattered section in the whole debris field. A lot of photography ahead.
____________

Below is this excerpt from the Canadian investigation into AI 182, which may be relevant to AF 447 if the tail did shatter.

“The depth of the wreckage varies between about 6000 and 7000 feet, and the effect of the ocean current, tides and the way objects may have descended to the sea bed was not determined, thus some distortion of an object's relationship from time of water entry to its location on the bottom cannot be discounted. In general, the items found east of long 12∞43.00'W are small, lightweight and often made of a structure which traps air. These items may have taken considerable time to sink and may have moved horizontally in sea currents before settling on the bottom. Marks left on the sea bed beside some wreckage does indicate horizontal movement of the wreckage as it settled.” "

http://www.publicsafety.gc.ca/prg/ns.../CASBai-en.pdf

I might add the entire wreckage trail for AI 182 was 6.5 NM, on a line 110 degrees true.

Last edited by SaturnV; 5th Apr 2011 at 19:10.
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Old 5th Apr 2011, 18:49
  #3046 (permalink)  
 
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I suspect that WHOI and/or the BEA people onboard know exactly where in the structure the CVR/FDR are located along with what they look like and will be giving extra scrutiny to the survey photos of the rear fuselage debris as they are retrieved.

I earlier suggested placing the CVR/FDR in the fin as it seems a buoyant and easily retrieved structure.
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Old 5th Apr 2011, 18:53
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Can someone comment on the recent CNN report that said oxygen masks were not down.

I would think this would indicate positive cabin pressure and no structural damage. How about the recovered stabilizer; what does that tell us?
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Old 5th Apr 2011, 19:25
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I would think this would indicate positive cabin pressure and no structural damage. How about the recovered stabilizer; what does that tell us?
There was nothing in the ACARS messages to indicate that cabin pressure had been lost, but rather to the contrary, i.e. the aircraft was descending at a greater rate than the cabin pressure controller could cope with. On impact the cabin pressure will have been less than the outside pressure, which would have caused a small implosion in conjunction with the major impact implosion.

The Vertical Stabilizer told us that it had left the empennage as a result of the tail impacting with the sea surface, as both compression and tension damage was observed.
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Old 5th Apr 2011, 19:28
  #3049 (permalink)  
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There is no reason to believe the VS separation (If at altitude) included the HS, elevators, or for that matter compromised the integrity of the aft bulkhead. So pressurization may well have existed at impact.

I for one agree with BOAC, as those who are vets of the prior threads know. I have believed in VS separation from the beginning (perhaps as early as initial upset). The location in the initial search of the port elevator suggests a separation also of the Tail feathers, but again, not necessarily at impact.

The early conclusions of BEA notwithstanding, to entertain that the VS was aboard at final impact challenges logic, as the condition of the sea floor debris would suggest. The galley stack included, the VS and cabin parts were no where near the final impact zone, as the extent of the destruction suggests, from the new photos. It also requires a substantial horizontal ("Thrown forward" and clear of) component, unlikely to have happened even in consideration of BEA's conclusion.

The condition of the VS has been exhaustively discussed prior, and this is not an invitation to continued speculation, at least by me.
 
Old 5th Apr 2011, 19:36
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The DFDR is mounted just aft of the rear pressure bulkhead:

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Old 5th Apr 2011, 19:42
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Machaca

Another one of your good pics. Thank you.

I believe the CVR is located about 2 frames aft of the rear door.
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Old 5th Apr 2011, 19:59
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Another one of your good pics. Thank you.
Yep

Would that be FTI kit being installed?? I ask because of the orange loom you can see between the top ladder rungs........I'm not sure on the 330 but I thought the recorders would be in a pressurised area rack...could be wrong of course.

... ain't this thread so very interesting? here's hoping that the authorities can finally find some more info and the families some closure.

GR.

Last edited by glad rag; 5th Apr 2011 at 20:54.
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Old 5th Apr 2011, 20:12
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Here is a FAA presentation (Powerpoint) regarding high altitude operations and conditions, which encountered, could lead to upset and a stall condition that takes some quick recognition and controlled responses to recover from.

http://www.faa.gov/other_visit/aviat...Operations.ppt

TD
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Old 5th Apr 2011, 20:37
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Turbine D's Powerpoint opens fine in OpenOffice which is free to download if you need it.

OpenOffice.org Downloads
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Old 5th Apr 2011, 21:13
  #3055 (permalink)  
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Opens fine in Google Chrome.

CW
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Old 5th Apr 2011, 21:27
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Thanks for the FAA brief, it was very informative for those who don't fly the big iron way up high on a daily basis.
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Old 5th Apr 2011, 21:51
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All ends well....

I'm tempted to believe that, despite all "expert" interpretation and background delivered to BEA before recently, in the end the arguments delivered on this forum on a "deep stall scenario" have led to start out the 4th phase from the area close to LKP.

I see no other explanation, other than BEA's staunch belief from the onset that AF447 could not have gone down south of LKP and pretty much all of the area north of LKP had been searched in previous phases, except where the A/C has been found now.

Of course a systemic search would lead to results at soime point, but for once let us applaud BEA, Airbus and AF that they got it right at this point.

That bypasses (and quite rightly so) a number of interested or fascinated people, including myself, who were uptil now convinced that the A/C could not be near LKP.

With the location of the debris field there is now a 100% probability that the FDR and CVR will be retrieved and we'll finally know what happened.

Not only will we have two years after the events conclusive evidence to give those berieved an explanation of the cause, but hopefully also the definite clues of how to mitigate a similar catastrophy in the future.

It has been and it is clear to me that neither Airbus, AF or the french government are ducking their responsabilities.

Dutch
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Old 5th Apr 2011, 23:08
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The exact location of the AF Airbus 330 crash site has not been mentioned before but the following article in the Guardian indicates a crash site only a few hundred yards from LKP:

http://www.guardian.co.uk/world/2011/apr/04/air-france-plane-crash-victims-found?CMP=EMCGT_050411&
"Scanning a circle with a circumference of around 75km from where the plane is thought to have crashed, the robots sent pictures back of wreckage on the seabed a few hundred metres west of the last known position of the plane."
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Old 5th Apr 2011, 23:33
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the following article in the Guardian indicates a crash site only a few hundred yards from LKP:
I'd take that as a reporters interpretation of something he may have mis-heard.
Without information very close to the BEA as the source, I would be very skeptical of anything I read in the papers.
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Old 5th Apr 2011, 23:48
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DjerbaDevil. the Guardian report is in error. The search at this point was not scanning a circumference that was approximately 40+ NM from the LKP. So the several hundred meters from the LKP is also likely wrong.

This journalist couldn't even get the flight destination correct in the initial article; he or she had the flight going from Paris to Rio.
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