AF447 wreckage found

[WilyB]

"have found the debris site. Notwithstanding it's a 3,000ft !" wrong - try 3900'

Actually, it is > 3,900 meters (13,000 ft).

[mm43]

Actually, it is > 3,900 meters (13,000 ft).

More importantly, the pressure is 378 Atmospheres, or 378 times pressure at the sea surface. Some may find that 5,562 psi is more meaningful, but remember a lot of the composites that have been carried to the bottom will have had any residual softness compacted, and the same goes for anything else. Tyres (tires) on the landing gear will have deflated at the rims once the pressure exceeded that to which they had been inflated. Water will be occupying that space.

[bubbers44]

mm43, thanks for that information. I think the tires are inflated to about 220 psi but was unsure what the water pressure would be at 13,000 ft. Yes, the tires would obviously be deflated.

[jcjeant]

Hi,

In France-Soir (French newspaper) :
Google Vertaling
Original link:
Crash Rio-Paris : Fiasco du bureau d'enquête français | France Soir

[takata]

Originally Posted by jcjeant

In France-Soir (French newspaper) :

Usual buzz for nothing.
People tend to forget now that this zone was already searched from the start by both SAR aircraft and the two French/US crews onboard the TPL trailers (Fairmount Glacier and Expedition). The main problem was that the recorders pingers could have malfunctioned.

Here is the map from Metron Inc. report for the BEA showing those TPL searches around LKP:

[WilyB]

he main problem was that the recorders pingers could have malfunctioned.

BEA says the detection range of the Underwater Locator Beacon (ULB) also called as Emergency Locator Pingers (ELP) is up to 2,000 m.

The manufacturer's technical brochure does give a detection range, but says the emission covers 80% of a sphere.

That would mean the microphone would have to be lowered by over 2,000 m to have had a chance at locating the pinger.

http://www.benthos.com/pdf/elp362D_001815_revK.pdf

[RiversInAustin]

Have you ever tried to find anything underwater in a reasonably challenging environment? I mean even in a spot where the parameters would seem to have it down to a fairly limited area ("it must be around here somewhere...", kind of thing).

Having failed after an initial, frantic, emergency search the group brain kicks in and tells you "it's not here, let's spread out guys". The theories get wilder from there on out.

I've been there, and also (totally coincidentally) personally involved in the final discovery and subsequent recovery 6 months later, which was (somewhat predictably and very much like this case) very, very close to the LKP

Nothing like the AF447 depths though, my experience involved puddle depth, a mere 200 fsw. I consider it fairly amazing they found any further trace mid Atlantic.

I believe the pinger(s) must have been down. There is no other logical explanation for not picking up signals during the first searches, unless I'm missing something totally obvious, generic conspiracy theories notwithstanding.

Whatever, this and the TechLogs original thread have been tremendous, thanks y'all.

[hefy_jefy]

Side scan sonar type

The REMUS 6000 has an Edgetech 4200 side scan as standard. That sonar image is not from an Edgetech 4200, it looks more like a SAS image (synthetic aperture sonar). It is a remarkably good image for such a long (600m) range.

But I repeat - that is a very flat seabed.

[Loerie]

AF 447

The pingers were heard by a French submarine,apparently.What is a point of wonder for me is why the area now known as the last known position,was apparently never properly searched by the very best that the World had to offer (as now done).Why spend millions of Euro`s looking all over way away from the LKP in an area which is hostile,with mountains and valleys with equipment that is not able to do the job as has now been done?If they had been looking,with the equipment that they have now,(which was available then)maybe the CVR and the FDR may have been found before they stopped transmitting.Looking for the Aircraft where it "may have ended up" seems to be a reckless endeavour,and not only financially.Why not look where it was supposed by most to be?I get the feeling,having followed this from the upset,that there is more to this investigation and search location then meets the eye with many possible insiders apparently bending the way the search may be conducted.At the present time we have about 6 pictures published and absolutely no information about the so-called Black Boxes,who is on site,what has been discovered,where the aircraft is actually lying (reporters do not have enough financial clout to dive to the area so why not say where the aircraft is----why the mystery).The cause of the accident needs to be peeled away layer by layer,and quickly;Was it an operator error,was it structural due to an overload by way of the vertical stabiliser which was carried away,was it simply an overload which no airframe could cope with?I am simply an unpowered (glider) aircraft operator and I find it very difficult to believe,with what has come to light so far (made worse by little information) that the accident was not caused by loss of the vertical stabiliser due to extreme weather and possibly pilot input in those terrible last moments.Where are the pictures---where are Woods and their underwater probes and why did it take so long for a proper and concerted effort to be put together to find a huge aircraft almost within hailing distance of where she was lost contact with AF maintenance.There is a smell here....The finals will be very interesting.

[MountainBear]

where are Woods and their underwater probes and why did it take so long for a proper and concerted effort to be put together to find a huge aircraft almost within hailing distance of where she was lost contact with AF maintenance.There is a smell here.

My mother always used to advise me, "never put down to malice what is best explained by incompetence."

Given that this search has been overseen by the French....

[Old Carthusian]

It is easy to see those who don't understand the ocean and the sheer difficulty trying to find anything once you get under the surface which is a totally different environment. Hindsight is a wonderful thing, gentlemen but we should remember that the BEA has found the aircraft and done a very fine piece of work. Parading a lack of knowledge is also not the best way to go about things. My training - start at the furthest point that an item could have reached and then work in.

[avionimc]

MountainBear's Mother: "never put down to malice what is best explained by incompetence."

... But do not rule out malice!

[Loerie]

AF 447

Points taken,guys but two years is a long time....how long did the search to find the SAA Combi off of Mauritius take?
I think,now that the wreckage has finally been found,that the shut-door attitude is quite frustrating for all of the folks on both this and the technical forum.And I am sure that those on the tech forum have input a huge amount of work and research.
Area to search?Given that money is involved I would have started at the last known location and worked outwards,not the other way around!

[SaturnV]

Loerie, if you have been reading the tech forum, the answer to your criticism of the search will be found there.

Very simply, search aircraft overflew the location of the crash on the day of the crash (June 1) and saw nothing. Why they saw nothing is a matter that needs to be examined.

But the logical thinking would be if you don't find evidence of the crash on the day of the crash when you overfly the crash location, then the plane didn't crash there. The result of them not seeing evidence on June 1 led them to searching elsewhere in the days, months, and years that followed.

[Loerie]

AF 447

Hi,
Did they not see the Vertical Stabiliser at that point from the air and some passengers and crew from sea level or was that later and well away from the LKP and what of the kerosene trace---that must surely have been from aloft?
I will go back and check,thanks.
Not really complaining or anything,just curious as to why the Woods guys were not called in right away.After all,it has taken them under a week to find the Aircraft very close to where it came down.Would just have thought,and bearing in mind all the difficulties facing deep-water exploration,that possibly more effort and money immediately spent would have worked better.
Thanks for the courteous post and reply.I have been more immersed in the tech side of the forum but do not have that kind of tech to comment----just putting down my frustration at the apparent lack of co-operation apparently from so many,including,from what I read,the Brazilians who seem to have been slow in supplying information to the French investigative body.
On a happier note----nice day in the BVI`s today....!
Cheers.

[cwatters]

The pingers were heard by a French submarine,apparently.

They didn't know they had heard them until about the middle of last year. Thales only made the discovery after writing new software to reprocess the data recorded during the first search. If I've understoof correctly this discovery caused them to extend the search plan by a month before the equipment was needed for a military project.

[Machinbird]

Search strategy

My training - start at the furthest point that an item could have reached and then work in.

If you are looking for something on the surface that is moving, that is a good strategy. You trap the item between its last known position and the furthest possible point and the search area should shrink over time as you clear sectors.

For an item on the bottom that is not moving, it may not be a good strategy.
The furthest possible position is a guess. The search area should not vary over time (except as new information comes to light) and the LKP is a good starting point (assuming it is reliably known).

Of course, the retrospective analysis approach can always find the flaw in the grand plan that should have been recognized at the beginning.

They did find AF447's resting place though and that fact should be respected.

[aston09]

Hi guys,
May be one day you'll understand french politics'.
Up to know, nothing, absolutely nothing has been done by chance or coïncidence.
Ref to my previous post to Know about the future (i'm not Ms Irma) ;-)))

[nojwod]

This thread is a classic example of why I love visiting these forums. I am always looking for ultra-talented people who can be head-hunted for international organisations who currently employ specialists and experts in their fields, who unfortunately don't have a clue.

Despite what the so-called experts will tell you, it seems that locating a downed airliner at 13,000' of Atlantic Ocean is childs play if you know what you're doing. All the finest minds in the various fields were simply incompetent. Our finest PPRuNe contributors should have been called up. All they needed to do was look at the various scopes and detection devices, locate the ping, from there send a scuba diver down to guide the robot submarine towards the wreckage, and while down there, before the SCUBA tank ran out, comprehensively document the cause of the crash, and issue recommendations for all future trans-Atlantic flights to prevent any possible mishap ever again.

[lee van chief]

nojwod,

Don't forget that while sorting out all of the above, they would also find time to spot spelling and grammar mistakes, moan about pay and allowances, and express disbelief that non pilots have the audacity to express an opinion on the mighty Pprune!
It does give us engineers a chuckle though.