First off, I am not aware of any information in regards to the location of the impact...

Surface finds are not indicative of the impact site, but narrow down the 'ground zero' factor.

In my opinion, as i have located many underwater wrecks, is that the aircraft impacted the surface at near zero velocity, ie a flat spin.

One can note that the current debris field, has few artefacts with the potential for aerodynamic drift...

Opinion: This aircraft impacted the surface at a near flat spin. Due to the prevailing factors, it is likely that the hull was breached prior to impact. Even at terminal velocity, the surface area likely caused extensive breakup of the remaining structure, but allowed for structurally dynamic assemblies to remain intact. Given that aircraft assemblies are not designed for forces in this direction, it is difficult to predict the load diagram, and hence failure mechanism, and relative points, cannot be determined without extensive case studies....

flat spin...near zero forward velocity is relative... the wreckage speaks for itself....remember the Titanic? the debris field was spread over 5 kilometers...

As I see you are from the dairyland,
when you go out tipping cows on Friday night, if you stand in front, will you be okay? exactly!

As lomapaseo has already pointed out, the concertina absorption of the initial 'g' forces through the collapsing of the belly section of the aircraft, resulted in only partial damage to the bottom of some items on the main deck. The galley is an example, along with a toilet/lav door which showed compression of composites over only a few centimeters along its bottom edge. Time v distance can turn an initially high 'g' force into nothing.

Also, one of the reasons the vertical stabilizer came away relatively unscathed.

concur...the galley section is an example of where the structural assemblies after the cargo and fuel voids coincide..

ie...a belly flop.

Machaca
 

Re Premier Plongee
http://www.bea.aero/fr/enquetes/vol....re.plongee.mp4

Did anyone else notice at time mark 3:14 to 3:17 there is a round canister shape at mid-left of frame exiting to bottom left.

Can anyone with better computer graphic capability than I examine those few frames, particularly at 3:17 to see whether this is the FDR Memory Unit that was found on Sunday 1st May?

Maybe I am reading too much into this, but if so, it is located very close to the FDR chassis, as shown by the large tube assembly at mid-right of frame that was also shown in the photos published by BEA on 27th April. In fact, that object appears in the still photo of 27 April. Unlikely, but makes me wonder if it was missed on the first path. To be so close to the FDR chassis would suggest separation within the aircraft on impact, but both chassis and memory unit were contained within the structure long enough to effectively descent together. Far fetched..... I suspect so, but a close look by a graphics expert would quickly eliminate this conjecture.

2nd box found
 

I just Heard on french news TV they found the 2nd box in a good state.

CVR found and recovered
 

Bea has post on its web site that they have found and recovered the CVR :D
Very good news !

From Bea web site :

BEA 3rd May 2011 briefing
 

3rd May 2011 briefing

http://www.bea.aero/fr/enquetes/vol....r1.reduite.jpg

CVR located
 

Grat news!!!

Pinger still attached. That raises questions now about effectiveness of phase 1 & 2 search.

CVR itself seems badly distoted by movement in a forwards and UPWARDS direction by impact forces.

Interestingly the CVR is still mounted in the ARINC tray mount which appears to have cleanly survived impact forces. The tray mount itself separated from the supporting structure probably due to manner in which the tray is attached to the airframe.

Sorry for our dear conspiracy theorists !
 

Thanks to BEA that did not give up, thanks to AF and Airbus that footed the bills and against tremendous odds (A/C lost at night, in the middle of the Atlantic Ocean, in radio silence and resting 4000m under sea surface),
the two "black" boxes have been found.
Of course, all the people involved in this tremendous feat have done all that just to tinker with the data contained in the boxes.:ugh:
Let's now wait for the data that we all hope is legible in the chips in order to understand what went horribly wrong that night.

Judging by the photograph, the location of the ULB (half buried vertically) didn't enhance its acoustic radiation capability.

Locating the missing ULB from the SSFDR is probably on the list of things to do, mainly to assess why it was not detected either. Then try finding the QAR for good measure, you never know what it may provide.

Great news :)

Why is that? Because it's half buried? Because it lies vertically?
(not an acoustic specialist at all, here, just wondering : one can't really asks an ULB to "kindly lie horizontally above the seabed in case of crash", can we?)

BEA is listening?
 

Did anyone take note that the BEA, on their briefing page:

Sea Search Operations, phase 5

... since 29th April, has been listing the English link ahead of the French link?
This is prominent in that the first two posts of 26th & 27th both listed the French link first.

It cant be geographical, a Brazil precedes all.
It can't be language, even those English precedes French, German and Portugese, as this would represent further deference to English, as French for "German" is "Allemand".

Maybe Bearfoil is finally getting to them! :=

Personally, I am very appreciative of the BEA's posts and photos. It strikes me as openness, certainly not gushing, but measured and respectful, and reassures me that finally, this sad and tragic accident will yield a factual description of the event. Hopefully not too long, as I hope they may release another Interim Report based on initial FDR/CVR data.

I can't help but feel profoundly saddened when reading an annotated passenger list ...
Unofficial Air France 447 Passenger List

Hopefully, their involuntary sacrifice can now be more certain of yielding data to lead to many more lives saved. Theirs, and their loved ones, has been a huge price. Their loss is respected if all who are now serving through these two finds, to unscramble this omelette, do so in a careful, factual, neutral, open manner. I look forward to this result.

Bizman
For me it looks like an Oxygene bottle....

JP Troadec interview
 

At 10h41 LT 08H41z on French Radio "France Info"

quick transcript

The outside of the CVR is good
At the end of next week BEA will proceed to the opening of the "boxes". It should be quick except if corrosion is present. Reading may take some days or some weeks accordingly. CVR records the last two hours of flight. We now think that we will be able to understand reasons of the crash according of the precedent elements of the inquiry and the present recoveries.
We will try to recover some pieces but not the entire aircraft because it would be useless for the inquiry and it is very long, about 6 hours to go up and down again.
Parts that we will try to recover are on board calculators because of their own internal memory, engines and the cockpit. It will be difficult for the cockpit because there are a lot of debris around.
I won't speak about bodies recovery. It is not the BEA mision but the one of the French Navy.

I got the 100-200g figure from an earlier posting that mentioned those figures in relation to injuries seen on recovered bodies, which in turn I thought must have come from BEA or authorities close to them. I can’t quickly find the quote.

The people were in the same fuselage areas as the galley, both remote from the immediate impact with the sea; and the lower parts of the fuselage would act as energy absorbers, but also with the whip crack possibility mentioned above enhancing velocity, and ultimately g as movement ceased; but it still seems remarkable to me that such a disparity can have occurred. I do know that queer things can happen in accidents. I have seen a very small number of aircraft and car accident details, but none of those led me to conceive of an anomaly such as posed here, if the g reports are anything like correct. One or two passengers may have experienced a particularly high and thus atypical g, but I am surprised that it seemed to be the norm, when the galley was so little damaged.

Anyway, thanks to those who responded.

@lomapaseo

If I deal with your question on pressure first; at 4000m, the pressure at that depth is 398atm, or 403 bar, or 411 kgf/cm2, or 5846psi, or 2.9tons/sqin. Starting from the point that a hollow object if present in a fluid at high pressure, is filled with air at normal atmosphere, and has a small hole, lets say a microfracture, water will enter, albeit veryslowly, but enter it will, eventually compressing the air to 1/400 it's volume and replacing the balance with water. Integrated circuits of the old plastic dual-in-line through hole type are formed by a solid layer of resin plastic which covers the entire microcircuit die. Ceramic devices (wide temp spec types -40 to +125C for the military) have a cavity above the microcircuit which if subject to high pressure is prone to fracture. Similarly, the small Surface mount devices (like we see in mobile phones), have an enclosed void under the die inside the resin, which again is subject to failure under pressure. Now, if the FDR/CVR armoured case leaks, water will inexorably progress into all parts of the interior, around the electronics, and cover The memory devices until, when the flow has stopped and there is no differential to the outside, they too are subject to the same pressure that exists outside of the cylinder. If the memory device uses a package which has a void, then it too may suffer a stress fracture, and again, water will find it's way in until the pressure differential goes to zero. Plastic IC's are now much more prevalent in aerospace than I at first thought. That being so, if plastic parts are used, then the porosity of the plastic will allow ingress of water without the need for any fracture event. The links below show how fractures may occur when IC's are stored in a damp environment and then suffer damage during the heat treatment process required to mount them on PCBs. In this case at far lower pressures since the material is in tension due to expansion, whereas, in compression they are much stronger.

http://nepp.nasa.gov/docuploads/A178...ems_final2.pdf

Moisture absorption

Regarding the question of equating acceleration on a person's body and that experienced by the FDR, and by implication, the CVR. The summarised findings of BEA's pathology report suggests a more or less horizontal impact. White's study (1993 The effects of structural failure on injuries sustained in the M1 Boeing 737/400 disaster) used injury analyses to allow direct comparisons with other linear measurements of a similar scale to show that severity of the injuries mirrored the damage to the aircraft. Similar suggestions were made by Cullen (NATO - Injury Mechanisms in Aircraft Accidents ) who concluded that the method be considered in the analysis of accidents where it is not possible to examine the crashed aircraft, such as accidents over ocean. The manual for civil aviation medicine quotes: Examination of the bodies of passengers can establish a pattern of injuries. Such a pattern may be uniform or discordant. A uniform pattern suggests that all the passengers were subjected to much the same type and degree of force.

For an accident over terrain, the forces acting upon the occupants are frequently less than those applied to the aircraft ie; the structures may show more damage than the injuries to the occupants suggest since the aircraft structures absorb energy as the collapse progresses. A water impact is different, and passengers are likely to be subjected to higher forces for the reasons explained before, namely; failure of the buckling absorption process in the structural members, and hydraulic shock to the floor structure. Once the skin fails, the drag profile changes as does the loading on the structural members. The floor then takes the brunt, and when that fails, the upper outer skin panels.

Passengers and FDR/CVR are, if I recall the details of a photo in an earlier post correctly, located at similar heights above the aircraft datum lower fuselage - maybe the FDR/CVR are a bit higher, though with a slight pitch up as mentioned in the report, this might have put the FDR/CVR to the same level or lower. So, as a first approximation, if we take horizontal impact on terrain as an exemplar, the stopping distance is similar, with the frames further forward of the empennage taking the energy until either the empennage contacts the ground or breaks away at a frame section. Hence my comment; the FDR and CVR may have experience something similar or less.

It can be argued that a small equipment object like the FDR could experience any number of pathways to final stop (air/water boundary), and that trying to predict how energy is absorbed and max G is fatuous. However, in this instance we are dealing with fluid dynamics where for a small object (low cross sectional area), the effects of drag, and by implication, retardation force is likely to be lower than that experienced by passengers subject to a hydraulic surge which pushes up against the large surface area of the floor. Examining the FDR photo I note that there is some damage at two points to the end of the casing consistent with contacting a hard edge, probably when the pinger departed. What is more interesting is the way the support fixings for the memory cylinder have failed. On the top two lugs where the earth strap is located, it looks like both bolt heads have popped off, while for the lower two, they look as if they are distorted - slightly bent. This suggests to me that the cylinder received a force low from one side which was sufficient to lift the unit, causing the bolt heads to fail, and bending away from the chassis (possibly explaining the chassis distortion) until the lower bolts failed, but not before bending sufficiently to remain trapped in the cylinder supports. Yet, if this was the case, then where is the associated impact mark on the cylinder paintwork? One hypothesis is that the cylinder was detached from the chassis as a result of fluid forces, and since the rising edge (dp/dt) of a fluid pressure pulse is less severe than a hard object impact, and the deceleration on a small object correspondingly less.

Could the cylinder have hit something else, the chassis for instance, and experienced a high G from that source - the answer is yes, of course. However, unlike the passenger G event, which might occur over a longer period, anything from say 100 to 300 ms, with a vertical vector, a detached memory cylinder is likely to experience only brief interactions, and varying vectors mitigated by fluid drag. So it's quite possible that the FDR experienced less G than the passengers.

Note: for ChrisN - Guidline from manual:

Injury sustained Deceleration
Nose - fracture 30G
Vertebral body - compression 20-30G
Fracture dislocation of C1 on C2 20-40G
Mandible - fracture 40G
Maxilla - fracture 50G
Aorta - intimal tear 50G
Aorta – transection 80-100G
Pelvis – fracture 100-200G
Vertebral body – transection 200-300G
Total body fragmentation >350G

Apologies for the length...

@ chrisN
if you take a currugated paperbord chair, his own wight is less than 1 kg, you can sit with a whight of more than 100 kg on him without problem or deformation
http://www.pprune.org/the%20gally%20...20construktionhttp://images.linx.de/linx/showcases_middle/26338.jpg

if the the same empty chair chrash with 100g, the deformation will not be bigger.....

the gally is a very light and very stable construktion

Does anyone know if the discovered debris field contains ALL parts of the aircraft (except for those recovered earlier from the surface) or if some sections are still missing?

If some sections are still missing this might indicate a break-up prior to impact with the ocean.

The converse however would suggest the aircraft was indeed intact upon impact.

@BJ-ENG one chrash-load to the CVR will be the falling FDR in vertical chrash....
http://newsimg.bbc.co.uk/media/image..._blackboxi.jpg

Partial transcript of the recorder's recovery procedure
 

Here is the transcript of the procedure that we can see at 1:34 in the "premiere.plonge" video (there's indication that the document that is shown is a draft as you can notice the word 'BROUILLON' in the background of the sheet) :

Very good news on the finding and recovery of the recorders. Question: Is the BEA, like the NTSB, usually quick to release preliminary details obtained from the recorders. Or, will we have to await the findings based on all available info?

Nice picture, Gritty.

If one follows your reasoning chain, it´s interesting to observe that the FDR seems to have suffered more damage than the CVR...

mm43, AZR:
IIRC, specifications in the brochure about ULBs stated the radiation is 80% omnidirectionnal. This would left about 40% of the power radiated upwards. It appears BEA was just unlucky during phase I having no listening device passing close enough to pick up the signal out of noise.

BTW, while they are at it, why not throw an ULB into the water and test how far it can be detected ?

Hmmm.... I thought these units on the 330 were not together... one on each side of the pressure bulkhead?

I'm not 330/340 endorsed, but I've been in the bowels of a few of them... Those I can recall (perhaps all 340's? - I can't be sure) have had the FDR and CVR mounted exactly as shown in Gritty's picture.

... I wonder if the press will ever stop calling them "black boxes"?

One falls on the other from above...or one is slammed into the other from below, pushed up by the water ?

Either way, I guess they could well have impacted each other in a flat impact with high ROD, and low forward speed

[EDIT / Note: other info points to the two recorders mouted differently to that photo on 330s, in which case this is all moot as they wouldn't be hitting each other]


It'll be interesteing to hear what damage the ULBs took and if they ever likley worked, or were simply not detected.

Full confession: I was a Doubting Thomas. Based on the assumption (wrong) that the aircraft went down in the "underwater mountainous terrain" area, which luckily is not where it hit the ocean, I figured that search would be fruitless once the first two phases came up empty.

Thankfully, I was very, very wrong.

What a bugger of a search problem.

The determination to find the remains of AF447 has not only been successful, but the team found the proverbial needles in the haystacks -- the recorders that will hopefully tell the tale of how it all went down.

I salute the folks who did the damnably hard work of looking at what wasn't working, trying again, and getting down there to locate, and retrieve, that which will unravel the mystery of why the flight deck crew could not recover from whatever interrupted the flight to Paris.


Here's hoping the recorders will divulge their data ...

I understand that during the recovery process for the recorders it has been found that to best preserve them and protect the contents they should be kept submerged.
Look at the Bea released photo's it does appear that the first recovered FDR is now sealed into a liquid filled container, (is it distilled water?), but the picture showing its extraction onto the ship seems to show it inside a mesh cage or lifting box and exposed to the atmos.

If this is the case, how rapidly will corrosion occur and will it occur in such a brief span of time, (as this hopefully was).
I have seen corrosion occur in a matter of ours on some materials, but will the fairly extreme conditions the recorders have been in affect how rapidly they can corrode.

Appreciative thanks to the airbus savvy and technical folks who have posted on here and fought the long fight against the conspiracy folks.
:ok:

CVR / DFDR respectives positions
 

To put the matter to rest :
- CVR is located before frame 73
- DFDR is located after frame 83
on the A330.
And between them is the rear pressure bulkhead (frame 80).
Quite hard to one of them ramming in the other one.

maby the picture was from an A 320
I´am not shure,

grity
 

Right on !
Both recorders on A320 are just before frame 74 as on the photo posted above.

I should know my memory is not to be trusted. My apologies.

Tail Fin separation (before or at sea surface crash?)
 

Jal 123 crashed. (LOC, but lost hydraulics too)

And it occurred also during test flights of CV880 and E8.

Instead test pilot Charles Fischer landed a B52:

Hi,

Possible crack ?? (FDR)

http://i.imgur.com/3Fmva.jpg

some observations on drift analysis and ULBs
 

With the two recorders retrieved and at least one of the two Dukane ULB's, it may be interesting to revisit some of the material on the earlier search phases.

It is striking that the "retro drift points" of the Brazilian Navy and of the US Coast Guard as mentioned in BEA's December 2009 interim report (page 80) are both less than 10NM away from the actual impact zone. They used the same model (NCOM - Navy Coastal Ocean Model, page 79). With hindsight quite accurate, taking into account the complaints about absence of sufficient reliable data on winds and currents close to the accident date.

The 2 June 2009 BEA Interim report states (page 46) that the ULB's had a limited signal propagation range of "two kilometres at most". Based on GPS data, the METRON analysis (figure 17, page 20) establishes that the US Navy TPL, tugged by the Fairmount Glacier, went 8 times over the 10NM (~ 18,5 km) quadrant (J30) of the impact zone before 1 July 2009 (i.e. within the 30 days of the ULB's certified operating life) with a "spacing of 2,5 km" (page 48 of BEA's interim report of June 2009), to take into account the "scan swath of the TPL which is approximately 2 NM" (= 3.7 km). This in turn is in line with the METRON report, which states on page 21: "The TPL sensors were assessed to detect the ULBs at a lateral range of 1730m with a POD of 0.90" (2x1730~3,45 km). On page 47 of the BEA interim report of June 2009 it is stated that the TPLs had an "average detection range" of "at least" two kilometres per TPL trawl. Presuming that the TPL, as foreseen, was trawled close to the (flat) ocean floor, this operation would have had a higher than 0.90 probability of detection at the time. Certainly now it seems that both recorders have been lying around unobstructed on that same (flat) and relatively firm ocean floor.

That is of course if one or both ULB's had functioned as per their certification. The METRON report also states that based on a series of aviation accident that ended up in water, it is relatively rare that one or both ULB's do not function. The estimate of a 90% survival rate for the ULBs may itself be low for a crash at sea that does not involve a fire, the report states.

We all know that the TPL operation was unsuccessful. It seems therefore of importance that the ULB's are inspected for possible reasons of failure. One has been retrieved with the CVR. Finding the one belonging to the DFDR may still be a priority for BEA.


PS @ grity: the photo you posted with the DFDR and CVR mounted on top of each other does not reflect the situation on board of AF447. The METRON analysis clearly states (figure 16 on page 19) that the CVR was mounted between FR71 and FR72, while the DFDR was located between frames 83 and 84.

some observations on drift analysis and ULBs
 

D Bru ,

I was always wondering why.

May be simple:

It seems because they tried to hear ULB as you mentioned.

After ULB´s batteries nominal endurance they abandoned "sites near LKP"

Quite logical but DELAYED THE INVESTIGATION.

It seems like an "strategy error" (procedural error)

Because area near LKP is small compared to areas of 1, 2 and 3 phases.

Easy to say now...

RR NDB

Yes, easy to say, but it brings up a flaw in the Search strategy. At the outset, and as early as possible, the BEA trumpeted, "Intact at Impact". Then the reliance was on ACARS to entertain "Continued Flight" into weather, and all manner of Radar excuses. This is how it must be read. A "Search" must include ALL areas that are possible, even those that fly in the face of the "Reputation" of what are arguably collateral players, pilots, union, Thales, AB, etc.

An upset and lack of recovery is not fatal to an argument that ACARS reception demanded controlled and continued flight after LKP, a situation which fed the biases of AB, AF, the Union, and frankly the heartstrings and prejudices of all who wished at least a fighting chance for our people.

Keeping 10nm away from LKP is (was) inexcusable, boneheaded, and incompetent. No human endeavour can trump Physics, let alone the parochial attitude of those involved. Why again is the DFDR inside the fuselage and not the Vertical Stabiliser ?? Given the "Good Luck" Airbus demonstrates re: the independent ability of the VS to survive horrendous crashes??

Two sayings on the wall. "Nature is relentless in her punishment of those whom are ill-prepared."

"No one deserves applause for doing what they are supposed to do."

A/C direction* when hit sea surface
 

Bearfoil,

Before i comment your post #598

Please:

Is the picture showing the debris field an indication of the plane´s TRAJECTORY? ("heading")

http://avherald.com/img/af_a332_f-gz..._090601_27.jpg

Estimated as approx. 250 degrees (SW)


(*) DIRECTION is not necessarily the same of HEADING during unusual attitude

Just an idea.
A roll of dayglo orange tape, say 50 feet long should be attached to the CVR and FDR so that it will unfurl and make them easier to find.