gums, this is a 1992 airplane so presume technology on it is 1985-ish in nature. The cheap and accurate toys we have today were unobtanium back then.

BJ-ENG, figure the tail section hits the water. Is it going to show the same ability to push into the water that the fuselage would? If not, what happens? The tail is pushed up relative to the fuselage. The nose of the VS can't easily go down. So the VS is pried loose from its mountings. The first thing it does is fly upwards, maybe a little forwards.

The actuator arm hints that as the VS came off the plane the rudder was off to one side at least somewhat. So the wind catches it and it's pushed backwards relative to the plane. The plane hits the water and doesn't stop its forward motion instantly. The VS flipped into the air will stop rather suddenly as it turns in the air and wind above the plane. I picture it flipping upwards, twisting like a playing card tossed into the air, and falling behind the plane by anything from a few feet to several dozen feet by the time it hits the water.

That would easily account for no dings on the VS, its unfortunate "nose job" at the front, and the particular damage to the mounts.

I don't see it "breaking off" from momentum or sideways pressure. I see it being pried off by the separation of the tail from the fuselage in a relative rotation upwards as the tail peals away from the pressure vessel rotating around a point a little aft of the VS's nose.

Edit: Of course, it's not as if I haven't been trying to explain this hear for the better part of two years now.... {^_-}

{^_^}

ACLS65, if the tail was ever submerged any great distance, say on the bottom, it'd never come up. It's strength, as I understand it, is from its more or less honeycomb structure. The tremendous pressure deep underwater would mash the honeycomb and leave it looking like a ripply flat ghost of its former self.

Even at 100' the structure would begin to crack and take on water, a feature that would have shown in its attitude before it was picked up. And it would show as surface blemishes.

{^_^}

Chris Scott, did I miss something here? When did we learn the precise point of impact? That's more important than LKP. And it's beginning to sound to me like people are presuming the point of impact equals the LKP. BEA hinted that's not so with a verbal wave "less than 10 nm thataway." (Or the French equivalent.)

So we can't talk anything about drift.

{^_^}

I also wonder if I missed something, illustration showing LKP and crash site. If true, very close together indeed.

JD-EE,

I am NOT assuming that LKP and sea-level impact are necessarily even in close proximity. If some "people are presuming the point of impact equals the LKP", as you suggest, I am not among them.

Quote:
"So we can't talk anything about drift."

Quite: the only "drift" calculation I've posted is what I called the "29-hour voyage" of the fin-rudder assembly between June 6 & 7.

We still don't have a very good idea of the sea-bed impact position, and certainly not of the sea-level impact position. See wes wall's comment.
As far as I know, the only indication the BEA has given is in their Presentation at a Press Conference on 4 April 2011:
http://www.bea.aero/fr/enquetes/vol....4avril2011.pdf
... in the form of a small map on Page 8. This points a large, but sharp-headed arrow at a point just under 10 km NNE of the LKP, which point it refers to as the "Accident Site (in the area of the abyssal plain)".
This "accident site" is presumably their indication of the approximate position of the debris field.

If the BEA's arrow is intended to be taken literally, it seems odd that they don't simply publish the Lat/Long: anyone capable of sailing to the area would be well able to infer the position from that map. That's why I'm disinclined to take it at face value.

Chris

This was my attempt to plot various things on google maps.

The centre aircraft icon is LKP. (The yellow circle behind it is the top of a yellow google maps marker). There is also an aircraft position at 2:00 I have estimated from BEA report, plus the estimated location of the rejected ADS-C.

The red zone around the LKP is my rough attempt to sketch Metron's "red" (most probable) zone from fig 33 of their report. I have marked the estimated northmost point with a purple pin to do that drawing.

The purple pins are the bounds of the circle of Metron's analysis area.

The red triangle is the first sighted location of the VS - June 7 2009 at 13h38.

The red cross is an APPROXIMATE wreckage location corresponding to the abyssal plain and the arrow in the BEA report. It is almost certainly not the actual location.

Body and debris locations taken from the phase 3 search zone working group report. I have not included all the bodies after the first few - it did not add much to the analysis.

Keep in mind:

• the first bodies were found at June 6 2009 at 11h55
• Body E1 (sighted) June 7 2009 at 9h11
• Vertical fin (sighted) June 7 2009 at 13h38

fwiw, my take is that the VS and bodies started from the same position in the water and drifted at about the same rate and almost the same direction. They have diverged little after about 5 days. Hence VS on until impact.

Chris Scott;
I don't think that getting into semantics about where and when the V/S was at any given time is going to help matters much at this time. My opinion on the published sighting position is (like some others I come across) that it has suffered from transcription errors. Using that assumption, I believe that the most likely sighting position was 3.41°N 30.62°W, and the recovered position was 3.47°N 30.68°W which is 305°T x 4.5NM from the earlier position. That gives a drift rate of 4.5 x 1852 = 8334m / (29 x 60 x 60) = 8cm/sec in little or no wind, so will equate closely to the current over the period. Is this plausible? Probably better than possibly.

mm43,
Oh dear, so you think the reported (sighting) posn of the VS on June 6 was 0.2deg latitude (12nm) north of where it actually was. I did wonder how accurate it might be, but certainly didn't suspect as big an error as 12nm. :rolleyes: Can't get the staff... :ugh:
You seem confident, so hope your transcription-error decode proves to be correct.

auraflyer,
No time to study your nice map tonight, but notice you report VS sighting as June 7. Should that be June 6? Also, you will now see mm43's reservation of its Latitude accuracy.

Me too, it's called the newspaper! :D

PJ2:

AA586 is not the only example of an aircraft loss after the VS was lost in flight. The B757 involved in the midair collision over Switzerland a few years ago had it's VS removed in the collision but was otherwise intact. The crew flew on for a while but ultimately lost control and crashed. In modern swept wing transport aircraft, yaw damping is provided through the rudder and directional stability by the vertical stabilizer. Loss of both would soon lead to uncontrollable roll/yaw oscillation, ie Dutch roll. The fact that the AF engines were found with the main wreckage would seem to indicate that they were with the aircraft at impact. If the VS and rudder had come off in flight, it might be expected that they would been found some distance away, as the kind of lateral forces which detached the AA586 engines would have occured in this case also.

777fly;

Thanks...I obviously hadn't recalled the exact circumstances in that collision although I certainly recall the outfall.

For practical purposes the point is made, that a swept-wing transport will not survive the loss of the entire VS using the only remaining controls available to the crew, differential thrust and possibly very judicious and patient use of small bank angles, and this, to be sure, does not begin to address the problems created by the swift loss of all three hydraulic systems, (for which, it has been pointed out, ACARS messages would exist in some form).

No matter at which point in the descent from FL350 to the sea, any crew response that could maintain some semblance of controlled flight would require enormous discipline and concentration and some luck.

Maintaining controlled flight may be logically possible under such loss as is theorized, but I think, highly improbable, especially under the circumstances faced by the crew.

Re-focussing - How they got there is THE question that requires an answer because loss of airspeed does not, in and of itself, result in loss of control.

I think we are left with explaining how the aircraft went from stable M0.82 flight, through a loss of airspeed data, to a high-speed vertical impact with the sea, with the aircraft intact.

The commentary regarding the Ile de Sein's and the Phoenix Remora 6000's capabilities provides the best hope of finding out and short of that, the photographs and whatever is brought to the surface for traditional accident investigation techniques.

PJ2

Quoting the 2002 Überlingen mid-air collision WIKKI article regarding the DHL 757 that had lost the VS, 2002 Überlingen mid-air collision - Wikipedia, the free encyclopedia
777fly's comment is most appropriate. This adds additional weight to the "AF447 VS was on at impact" explanation by BEA. Once we see some sort of chart of wreckage location on the sea floor, we will all know for sure.

It boggles my mind how some participants in this forum continue to seize on loss of the VS as the likely cause of the AF447 accident. Loss of the VS in-flight is probably the most discussed concept in this thread.
This single-mindedness is not an asset and detracts from other explorations.

Lets hope the recorders will be found. It will however be a real shame if the recorders are found to be inop as a result of exposure to pressure/seawater beyond the design spec.

Is it a all or nothing deal with the data on the recorders?

ventus45...

Yes indeed. If we accept BEA's view of the likley impact sequence, that outcome is certainly in the area of "possible" as opposed to "unlikely."

Depends very much on whether they are lying (buried) within, or very close to, the rest of the debirs field.

I am optimistic (as are others I have spoken with) -- but certainly not confident.

Yes of course.

As fatal aircraft accidents go, AF447 was one of the more 'gentle' ones. There was no rock-like surface to break the recorder shells, only other aircraft structure. The pressure is a real concern as is the duration on the bottom.

It is very likely that the fuselage broke around the door opening areas judging from the floating wreckage recovered, thus the area forward of the aft pressure bulkhead probably no longer forms an enclosure.

Similarly, the lower skin aft of the rear pressure bulkhead was likely sheared as a result of hydrodynamic forces and uneven support of the skins in the area plus the removal of the "roof" of the compartment when the VS was torn away and the HS was almost certainly torn away too, so it is likely the recorders made an independent trip to the bottom.

The difficulty in locating the pingers suggests that they were buried in the sea bottom to some extent.

I expect that the recovery team will grab what is left of the tail and check it out only to find it missing its recorders. That is when wreckage distribution theory will come into play.
Once located, the recorders condition determines what will be necessary to get them functional. If they are still dry inside, the probability of data recovery is very high. If flooded, data recovery is still possible, but will probably require the manufacturer's assistance to have a chance of reading data.
I believe that the data resides on an array of static RAM chips of some type but feel free to correct me.

I find it interesting that of the 100,000 photos the BEA claims to have taken that they only chose to release less than a dozen.

Really, are there human remains in 99,988+ photos that therefore restrict disclosure?

Really... The recovered pieces and released photographs do not show the type of low level destruction of the Afriquiyah accident.

Machinbird;
I would not want to criticize theories if they are developing and/or promising, but if someone believes something strongly, in this context there is the requirement for substantiation.

Determining that the VS was attached at impact takes the examination of this accident in one direction, and assuming the VS was lost at altitude takes it in another. That is why it has been a constant source of discussion between contributors.

If the problems with the VS-loss theory were addressed such that the evidence of the recovered wreckage and the photographs were accounted for, I don't think anyone would resist the notion.

However, a number of contributors have provided sufficient opportunity to demonstrate the validity of the theory against specific objections, and have found no response.

The idea isn't to shut down a path of thought but to test a line of thought against serious objections. That is the way investigations are done. The theory must make sense. If the evidence does not support a line of thinking, the thinking must change or it becomes irrelevant to the investigation.

I think using what we have and our imagination to consider how an aircraft cruising at M0.82, ended up in a high-velocity vertical fall, is the most important question to consider.

I believe that examining everything after 0135, (INTOL) is important. I think the fact that the crew did not respond to DAKAR's request for their TASIL estimate is significant.

I'm sure others here will have been in similar situations, but in the initial contact from VHF to HF, there is a routine process. For a few moments, waypoint passage is a busy time, recording passage on the flight plan, checking the track and distance for the next leg, confirming ETA for the next waypoint, observing/recording fuel, preparing (tuning) the HF for transmission, making contact with the HF, (dealing with the CPDLC log-on issue in this case), providing position and estimates again on HF and doing the SELCAL check and responding that the SELCAL checks, (or repeating the check if it doesn't work first time) are all routine procedures.

But after the initial contact, the crew didn't respond to three requests for a TASIL (the FIR Boundary) estimate from DAKAR, (and then DAKAR gave up!). I am wondering if the process was interrupted by something and if so, what?

I think things began to develop before the loss of airspeed, and were compounded by the loss of airspeed in a situation they were already wrestling with, (was the radar on and were they using it to best effectiveness?). These are the questions that I believe will help us understand what happened around 0210.

Clearly to those who have stuck with and read the thread, none of this is original. But it is an attempt to provide focus on what occurred at FL350 after INTOL.

PJ2

I agree, but many on this site refuse to trust/believe the BEA. The BEA is not obligated to share all the information that they are collecting at this time. This after-all is a criminal investigation as well...so please be patient. I for one am encouraged at the accelerated pace of the proceedings!

http://www.pprune.org/images/statusicon/user_online.gif http://www.pprune.org/images/buttons/report.gif http://www.pprune.org/images/buttons/reply_small.gif

Not to belittle your comments, but there is a need to substitute ATLANTICO for DAKAR.

The only time that DAKAR got directly involved in this flight is after after the a/c had passed INTOL and ATLANTICO passed them the a Virtual Flight Plan by AFTN when DAKAR advised they didn't have a Flight Plan for AF447. From memory I believe they had received it but the call-sign was entered into the system incorrectly, and as a result the ADS-C failed to allow the log-on due by 0200z.

DAKARs later involvement was "after the fact".

That ATLANTIO didn't follow-up on their 3 requests for a TASIL estimate by SELCALing the a/c has at this junction of the investigation not been questioned by the BEA, other than noting it as a matter of record. Neither did ATLANTICO attempt to contact the a/c at either SALPU or ORARO, waypoints for which times had been given by AF447.

PJ2,

Quote:
The idea isn't to shut down a path of thought but to test a line of thought against serious objections. That is the way investigations are done.

Agreed. I think that it is equally incumbent on those who disagree with a clearly-stated point – and who have competence and experience in that area – to provide a specific counter-argument.

Quote, re the period prior to 0210z:
I think things began to develop before the loss of airspeed...

Yes. Things were developing, and are probably the key to the events that followed. But, if you refer to the first discrepancy in the flight regime, I don't think we can assume that it was necessarily a loss of airspeed.

If we stick to the theory of progressively freezing pitot-probes, it is unclear whether they result in an over-reading of airspeed, or the reverse. The BEA analysis of previous events shows a large proportion of cases where a stall warning occurred. In every case, there had already been a reversion to Alternate Law. As I understand it, the stall warning in Alternate Law is based on indicated airspeed falling to a certain threshold, not the AoA. As the indications are unreliable, the stall warning might have occurred despite the airspeed being normal, or even above normal.

To be simplistic: if a pitot tube is blocked, but the static is clear, that is very likely to result in an under-reading of airspeed. (We've visited this one before...)

Regards,
Chris

PJ2 - to save my trawling thousands of posts, do we know if contact between the two oceanics about no 'comms' took place and whether Selcal and 123.45/121/5 was used?

Chris,

To begin with the last point, if a pitot tube is blocked, but the drain hole(s) and the static are clear, that is very likely to result in an under-reading of airspeed. That was the case in all thirteen cases of UAS studied by BEA (see Interim#2, 1.16.3)

In the same paragraph, BEA writes about Stall Warning: And in para. 1.6.11.4: I have a few questions about this, which I hope BEA will see fit to address in their next report:

Firstly, 4° at Mach 0.8 is rather early (compare to recent discussion on a 777 incident), with the risk of becoming ineffective because pilots then consider it 'inappropriate' (see Air Caraibes memo).

Secondly, 10° at Mach 0.3 is too late, when the speed drop is due to pitot blockage while actual speed is still Mach 0.8.

Finally, the occurence of stall warning in the cases studied by BEA does not seem to match the higher threshold after loss of IAS.

Regards,
HN39

mm43, for that matter the BEA has yet to discuss or release any transcripts of conversations between ATLANTICO and other flights on that track that night. IIRC, AF 447 was the only flight that did not diverge from the track on encountering the mesoscale convective complex.

LH507, which is suspected of being the flight with AMDAR, is mysteriously omitted from the BEA interactive map of the tracks that night. Why? Proprietary data, or does LH507's experience encountering the ITCZ leave too many questions yet to be answered?

Perhaps I overlooked it, but I have yet to find any reference as to when AF OOC looked at the ACARS messages. These seem not to have raised any flags at AF OOC at the time. AF and BREST still seem to be looking for the whereabouts of AF447 through 09h00. It is DAKAR at 09h40 that alerts French Naval Aviation that a plane is missing. French Naval Aviation goes on alert, contacts BREST, and several other centers in France. The BEA reports do not indicate when Brazil was contacted, or by whom, and asked to commence a search.

Asleep at the switch, anyone?

I would expect the BEA to ask the Drift Analysis group to do a re-analysis, and assess and explain why they and their models produced results that were so far off the mark. Until that happens, all the meteorological and oceanographic data on windage and current has to be looked at skeptically.

I increasingly think that French naval aviation and probably Brazil overflew the impact site on June 1 and saw nothing. Its possible that convection in the area later that day meant poor visibility or that parts of the area that supposedly were searched was never truly searched. In that event, the search should have been repeated when conditions improved, but was not. If this is the case, the result was 22 months of uncertainty, millions of Euros spent in wasted effort, and delays in getting to the boxes.

As I recall, didn't bad weather hamper the search in the early days: poor visibility and a high sea state may explain missed sightings.

IIRC, in the weeks following the accident, AF CEO explained to the press that AF Maintenance first looked at the ACARS messages when they began routine preparations for the arrival of the flight in Paris, IIRC about ETA-1hr .

Khashoggi:
 

Really, are there human remains in 99,988+ photos that therefore restrict disclosure?

I have to agree with you. Something is not right here...

HN39, thanks. That meant they looked at them around 08h00, and apparently nobody thought to look at them earlier.
----
4h20 AF 459 tells DAKAR they have been unsuccessful in raising AF 447, and have sent a message (@ 4h18) to AF OCC to this effect.

4h24 AF OCC sends an ACARS message to AF 447 asking them to contact DAKAR.

5h50 AF OCC contacts Search and Rescue Satellite Tracking Center and asks if they have any beacon transmissions..

Between 6h00 and 7h30 approximately, AF OCC and the following centers are talking with each other on whether there has been contact with AF 447.
SANTA MARIA, SHANWICK, CANARIAS, DAKAR, LISBOA, MADRID, ATLANTICO, BREST, CASABLANCA,

"At 7 h 29, the Air France OCC called the BREST centre to state its concerns over AF447. It stated that the airplane was not in contact either with Brazil or with Senegal and that the attempts at communication using the ACARS system, SATCOM and Stockholm radio were unsuccessful."

^^^ No reference to the ACARS messages that had been sent.
______________________

Mr. Optimistic, the Drift Analysis group said there were voids in some of the satellite imagery of the sea surface on June 1 because of rain in the area. However, every low-level aerial search grid that was flown in the days following seems to have presumed that the June 1 search grid was adequately done. The first sighting of floating objects from AF 447 was made by a passing cargo vessel, not an airplane.

wreckage location?
 

Mr Troadec said that wreckage were located at about 3900 meters depth.

I searched for an area in GE starting at about 3850M depth or below and delimited this area with markers.
There is also the picture published by the BEA to help.

The result is here below.
The area should be read clockwise starting ie NW1-->NW2-->N1-->N2-->E-->SE1-->SE2-->S-->S1-->S2-->SW1 -->WO2-->NW1. Depth inside this area should be at or below 3850. Please allow some inexactitudes. There is a "peninsula" extending southwards from SO1/SE2 towards S points. Inside this peninsula is a limited area above 3850M depth.

The area would be delimited by the markers listed below.
LKP 2.980000 -30.590000

NW1 3.085187 -30.667351
NW2 3.092785 -30.665565
N1 3.105311 -30.635955
N2 3.107749 -30.576287
E 3.075085 -30.554822
SE1 3.053872 -30.570126
SE2 3.059476 -30.610205
S 3.037939 -30.626338
S1 3.0000628 -30.605944
S2 3.006704 -30.630662
SW1 3.052021 -30.635182
SW2 3.062580 -30.652065

From the picture published by the BEA, with the position of the arrow, and the scale indicated, wreckage could be at 8.5 KM/4.59 NM in the North of LKP and slightly towards the East. It is not very reliable and precise because it is impossible to say if the arrow points to the exact location or a global area. The extremity of the arrow would show wreckage position nearby the SE1 point at about 3.056226 -30.576041 at a depth of about -3870 meters.
GE allows to "dive" and observe the bottom of the ocean in a somehow flat grounds area surrounded by mountains in the north and other higher grounds southward.
Markers can be positioned with GE at the bottom of the sea to keep a visual contact.

Quote:
The Remora robot can work as far down as 6,000 meters. To ensure steady operation, a team of nine Phoenix experts will operate the 900-kilogram sub from the ship using large video monitors to track its progress. Every movement of the vessel at the surface is translated to the Remora's umbilical cable with a delay, said Brennan Phillips, manager of ROV operations at the University of Rhode Island in the U.S.
Delayed Reaction

"If the ship moves, it takes half an hour for the vehicle to feel it," he said. "You need an extremely stable ship."

I wonder why they don't use a compensating system (hydraulic-air) like used on the drill rigs (semi) or DS for the risers tensionners and on the derrick travelling block



This is odd. Why no Tether Management System?

Hi,

I have been very surprised of this "(very?) hign sea" in the accident night and subsequent days" when I saw this picture :

http://i24.servimg.com/u/f24/14/14/01/64/image-10.jpg
(picture is a cropped one from:Todesflug AF 447: Die Bilder vom Wrack auf dem Meeresboden - SPIEGEL ONLINE - Nachrichten - Panorama)

How this box was able to stay in balance for several days? And more: it seems there is a bag just under the box. Kind of fabric handbag? Just left there by crew people as they often do?

About the same picture: damages to the structure from vertical G seems low. And the box on the top don't seem to have any deformation. Perhaps it was empty at this time of flight?

In the same categorie : as the wreckage area on sea bed seems small, the wreckage at sea level just after the impact had to be small also. So how could it be ignored if the place was trully searched? (no mismatch, it is not a critic to search teams, just a question).

Sorry if those questions have been discussed before,
Regards,
S

As above, one problem since the accident has been a less than appropriate approach to the collection and evaluation of crash evidence. Politics, both International and internal, as well as corporate, have corrupted what should be a transparent and straightforward exercise, period.

No one to my knowledge has held fast to any theory that suggests the VS was the cause of upset, or for that matter separated completely before impact. Damaged? Certainly. Its find stimulated an ongoing discussion of many things aerodynamic and flightworthiness.

This forum is not, in my mind, the venue to determine what happened, and studious and awesome academic discourse notwithstanding, the bickering is evidence of that.

BEA is the fulcrum of the interest for me. Searches, politics, wild corporate statements and defenses have been the tenor, the "reports" crazily political and obfuscatory, to put it mildly. The Investigative authority is compact and witholding for trite and sadly historical purposes, to selfishly retain "control" and pre edit the finality of this tragedie's outcome for protection of the guilty, rather than the innocents.

Any reasonably proposed "what if" should be welcome, if only for its catalytic value. No one has the grail, and if the heat diminishes on the principals, no one ever will.

bear

On sea state etc I was recalling press releases from the very early days: given the storms it still makes sense.

Bad weather is hampering the search for bodies and debris from an Air France jet that crashed into the Atlantic Ocean, Brazilian officials said Friday.

Not sure why the limited number of photos released to the public is so difficult to understand. There isn't much interest in the general public and the only non-industry group that would matter are the relatives and can't see them caring too much about the distributed wreckage, in fact they may find it upsetting. So enough photos to prove the point and that's it. Pity, but understandable.

Engines found where?

Recorders sunk in mud ?

99,9995 pictures being witheld


Just to remind, the TWA800 engines were separated in uncontroled flight and yet were found in the debris field, so let's not be too conclusive from just a single picture out of 100,000

looking at both the engine picture and the one with the gear it dosesn't look like they have sunk very much into the sea floor.

Give a thought also to TWA800 and the thousands of pictures taken on the seafloor that you have never seen..

Photos are released as the invstigating body sees fit to keep the public informed. After the experts decode all the various bits of information both for and against theories they typically release critical bits of facts (photos and recordings) that the experts feel corroborate their findings. They are not in the business of feeding theories that may end up diverting their resources from the expert based task at hand.

be happy that you got something that at least shows where the investigation is at.

eg. 447's 'impact' started at altitude, and because the 'impact' was initially with air, (turbulent and vertically developing), the remark that she was intact at water entry is a likely false conclusion. I doubt she slowed much below .82 at first, but rather accelerated, and combined with turbulence, confounded her instruments (passive and active) into an ACARS jumble that decieves if one keeps a narrow mind. Know that a narrow mind is the goal product in the public v/v BEA. From the outset, AF and Gourgeon were clutching at any 'explanation' that would even put a crack in their obvious culpability. Along comes Airbus, and Thales becomes the criminal. A Labor action by the pilots was meat for the feast to AB.

Overspeed, turbulence, and a baffled computer and auto pilot? This accident is not a textbook one. Reliance on the way things have behaved throughout transits of the ITCZ in history will not suffice. BEA and the others have created (and welcomed) all that can be imagined in the way of keeping solutions from the public. Secrecy is for the old Eastern Bloc, this is a new time.

edit
having just this moment read lomapaseo, I thank you for demonstrating the mindset of the authority. Well said.

edit
#3787, shadoko.
May I direct one's attention to the strut supporting the shelving (box) panel of the cabin structure in the excellent photo?? I'll repeat from a year ago, I have seen far greater damage to such a structure after one of these was dropped off a loading dock from two meters. Some thing is wrong with BEA's report?? Different airplane?? Different impact?? Altitude??

I think you need to look at the time of the incident and the time the search really going - more than 7 hours later? - i suspect the wreckage was 'over the horizon' W/NW of the LKP when they first overflew the track from LKP to the 'Estimated final ACARS transmission' which we later learnt was just extrapolated to be some 8NM off-track - 40NM further on. Guess they were also looking for a ditched aircraft and life-rafts early on.

As the search was widened it appears the wreckage moved back towards the LKP, possibly seen South of the LKP?, and then North till it caught up with the search and by then was spread out over more than 100NM.

Recorders to be retrieved early May
 

A French article suggests BEA knows where to find the recorders and will retrieve them as their first priority:

Le Figaro - France : AF 447 : mission repêchage des boîtes noires

Agreed, and lets not forget that the TWA800 investigation took 4 years to complete and was shrouded in controversy. So this investigation is nothing new....in that regard...

sensor validation

Why would one exclude the area about LKP to be assiduously searched and researched? A proprietary instinct that one's a/c would look dismal if found to have "fallen" from the sky rather than soldier on in spite of the "unlucky pilots" who missed the cell everyone else had "luckily" avoided? Poor dumb inept pilots, after all, the machine was stall proof and had far better breeding than a fall from great altitude would challenge?? Talk about unfortunate theories on PPRuNe, they actually started with the first unanswered Selcal? No monitoring of the a/c's flight in Paris? Unplug, damage control, blame, distract, redirect, dim the lights, etc. This flight ended in a typically corporate and political CF with the all too eager Press rabidly promoting the drivel from Paris and Toulouse.

imho.

About the article in "Le Figaro"

Excerpt:


Parmi les débris photographiés, pas de trace des boîtes noires mais la partie de l'appareil qui les abrite a été formellement identifiée et localisée. Il s'agit de la pressure bulkhead, la paroi qui sépare la partie pressurisée de l'appareil de sa partie non pressurisée, à l'arrière. Sur l'Airbus A 330, les deux boîtes noires sont fixées de part et d'autre de cette cloison.

"Among the debris photographed, no trace of the black boxes but the part of the aircraft which shelters them has been formally identified and located. It is the pressure bulkhead, the wall that separates the pressurized part of the aircraft and its nonpressurized one, at the back (of the plane). On the Airbus A330, the two black boxes are fixed on each side of this pressure bulkhead."

Personnal comment:
Since the beginning, "Le Figaro" seems to have been always very well informed.