Consider three factors that would arrest momentum in the NNE direction of the flight as it was supposed to be flying at 30,000+ feet.

1. Aircraft was most likely not in controlled flight (more likely stalled). Had the stall been a simple "nose falls stall" it would a) have been more recoverable and b) likely been arrested before impact with the sea during the five mile plummet.

2. An upset/stall is likely to develop a rotational feature. The more the aircraft rotates, or has a post stall gyration, the less likely "initial heading" can be preserved during X rotations from 30,000+ feet to 0 feet.

3. Debris field has been subject to various oceanic influence, which were not necessarily aligned with the direction of flight. Unlike a crash that hits the ground, final resting place of this aircraft after impact will move ... in this case, due to both wind and water mass movements.

Put another way, I'd be stunned if the debris field were to have coincided with the selected course (NNE) that was to take the flight to Paris. Had they been able to maintain course/heading, I doubt they'd have crashed at all.

Well, the latest (Dec 2009 IIRC) report does seem to indicate the aircraft was near-wing level upon water contact.

Point taken... still was the first thing that looked very odd. I would suspect that even upon water contact some forward moment (and some was supposed to have been present judging from material analysis) would've remained and would have formed at least the basic "spread" before floating to the seabed. But yes, I see your point. Too little info to make an (educated) guess.

Fully agree on that point. Too confused about both the location and the spread. :rolleyes:

D.

Lets hope the boxes are found and closure finally brought to this tragic incident.

Question regarding the tyres in the photos. I am surprised they are not crushed / squashed by the pressure at that depth.

Looking closely at one of the tyres one can see that it has been ruptured near the rim. I assume it has returned to its uninflated shape..but is full of water at ambient (4000m) pressure.

Machaca, in the overlay to mm43's graphic, the location is probably to the west of the arrow tip. mm43 carefully drew the first day's aerial search grid (the yellow box) along the flight path, and unless the Brazilians were blind, the location is probably several kilometers to the west of that first search grid.

As has been discussed for many months, the subsequent searches in the several days following were to the right of that yellow box (i.e., to the east) along the flight path.

From an academic standpoint, it will be interesting to learn the reasons for the current and drift reconstructions having been off.

i would epect the tires to only lose their air when pressure was great enough to break the rubber seal with the rims, but not explode from the pressure.

I haven't read the BEA report but from what we've seen so far we can determne that:
- it was a relatively low speed impact (somewhere less than supersonic) with the ocean surface as the airframe wasn't broken into tiny bits
- if all sunken major airframe parts are recovered in that small area then those airframe parts were likely connected at impact rather than seperating at altitude,
- the fuselage was opened at some point (upon impact I expect) because the previously recovered galley came from within the cabin,
- we don't know how long it took sea creatures to consume those lost in the Titanic because searchers got there so many years later.

Glad to see they found it

Bodies found in wreckage
 

France says finds bodies in Atlantic crash wreckage - Yahoo! News

D. Fisher

The CNN piece today said the oxygen masks were not imployed in the recovered wreckage and that implies the airfame was intact (pressurized) at the time of the ocean impact.

robertbartsch;

intact yes, pressurized no. The negative pressure relief valve equalized cabin pressure shortly before impact.

regards,
HN39

Is it just me, or does it look like the engine in the picture had not been turning at the moment of impact. If it had, you would expect fractured or bent blades all around, not just on one side, wouldn't you? Could suggest they suffered a flame out.

The missing blades presumably would have been around 6 o'clock position and were ripped away on impact, but since the engine wasn't turning, the blades that were closer to the 12 o'clock position were preserved. Sound plausible? Or am I thinking too much of props?

wreckage location
 

Won't the location of the debris become very obvious once the recovery vessels turn up ? Before then, what is the risk beyond a boat load of photographers ?

Mr. Optimistic, it may be that France and/or Brazil need to establish a maritime security zone. and are working on the boundaries and procedures for doing so. If such a security zone is established, the national government(s) would be able to keep unwanted vessels and aircraft away.

Do you really want a load of paparazi taking photos of an open hold with bodies inside it or the potential of a body being able to be seen via a window ?

After all, they would publish it if they got the photo.

I would like to see a Maritime exclusion zone around it.

.

Though the BEA have chosen to keep the exact location of the debris field secret, my best estimate would be that its about 335°T x 6.5NM from LKP. This is based solely on where I suspect the "Alucia" was working, i.e. she had completed the keyhole section in the rugged terrain to the NW and was working in an unfinished section to the south. I could also be totally wrong.:=

http://i51.tinypic.com/zoe4ci.jpg

Yellow circle radii are multiples of 10NM from Last Known Position.

Added another overlay of debris recovery locations.

I wonder what items 9 and 11 are...

http://i337.photobucket.com/albums/n...F447site04.jpg

Though I remember questioning the relevance of an item of debris located close to where the debris field is believed to be, I consequently dismissed the recorded location as being a transcription error where a handwritten 3,66 was later transcribed as 3,11 (3.66/3.11). I am starting to think that maybe that assumption was wrong, and the debris in question had made its way back to the surface.

Post #911 clearly shows the location and date of recovery of that debris item.

I don't see any blades visible, non-rotating struts yes.

Of course the pics are4 quite low in resolution so far.

Occams razor suggests the most likely scenario is the engines were on the bottom of the wing when it hit flat shearing away all the soft structure around the engines (Large diameter cases and nacelle0, but leaving intermediate case behind the fan mostly intact.

Let's wait and see if any better photos show up.

Debris size & speed
 

After a high speed impact, the SR-111 MD11 disintegrated into 2 million (recovered) pieces*. CNN reported the biggest one was the size of a car door. The average length of the 160 miles of wire recovered was 3 ft. The large size of the debris spotted today clearly points to a very much lower speed at impact.

*Swissair 111 Crash Report Delayed

PJ2,
I know how familiar you are with the airplane and have never been near it myself. My comment was based on the lower wing skin visible just to the right of the upper end of the MLG leg, that is in the way of retracting the gear towards the right. If you are right, then it must be a wheel well door, since the gear retracts towards the fuselage. If that is a door, then it being in closed position would be counter to the theory that the gear was released from the uplock due to impact forces. Are you sure the structure to the far right is not a flap track (*)?

regards,
HN39

PS: (*)BEA Interim Report #2 has photographs of flap track 3 on pp.20-21

Attitude at Impact
 

http://i34.tinypic.com/bg5kqh.jpg
http://i34.tinypic.com/sb3l88.jpg

From a previous post.

Tyres
 

"Question regarding the tyres in the photos. I am surprised they are not crushed / squashed by the pressure at that depth."

Rapid water ingress. All air squeezed out.
But rubber itself is compressible.

So the tyres should look much smaller then normal, which I think they do.

mm43, are you suggesting some kind of deep stall? I doubt an intact and in-CG air frame would maintain your depicted attitude and velocity vectors.

Why so?

deep stall or spin, vectors look about right?

HN39,

You think you are looking forwards at the R/H MLG; whereas PJ2 sees himself looking aft at the L/H MLG.

However, the MLG is normally mounted on the rear spar, at the intersection point of a diagonal bracing spar, sometimes referred to as the "Bermuda triangle", so I agree with you that the top-right item is unlikely to be part of an engine pylon.

Chris

ZeeDoktor

I will need to go back and dig out the post which had the Attitude at Impact images included. I believe I was referring at the time to a form of Deep Stall where the aircraft was slowly spinning within the vortex it created. This possibly as a result of an non-recovered stall. The BEA in Interim Report No.1 made mention that the tail was rotating to port at impact.

It would seem that based on the vectors, and if the A/C was within CG limits, positive pressure at elevator wing surface will induce pitch down moment, thus not maintaining positive pitch angle. There is no elevator shadowing from main wing components (which is the definition of a deep stall, really). Could a transport category aircraft be certified if a deep stall condition can be produced simply by stalling in a double flameout / power idle? I don't think so.

EDIT: Unless spinning of course, you are correct. It took an incredibly unfortunate conspiracy of fluid dynamics to get them into this state!

August 2006, the TU 154M near Donetsk, stall at 39,000 feet, [presumably flat] spin, fell 14,000 feet per minute max. Impacted 3 NM from the onset of the upset.

Lots of use of the term "deep stall" here recently but don't you, almost by definition, need a T-tail for that?

Yes HN39,

As I tried to explain, I'm with you on this one, for what it's worth. The engine and pylon are mounted on the front spar, so do not feature among the parts in question. We are looking forward at the R/H MLG.

HN39, Chris, I agree with you, thanks - sharper eyes than mine. The other gear (partially buried truck) would be the left, then.

@wiggy: Yes, for a classical deep stall. But if combined with a spin, you can produce a similar effect (a vortex) with non T-tail a/c. At which point, deep stall simply means a stall which you cannot terminate unless positive power input is available to re-attach air flow across control surfaces.

One way to get there, fast
 

Lose control into a spiral dive due to a loss of instruments, go near sonic in the descent, come out of the overcast and be able to see the water and even the horizon what with lightning and/or the moon, roll to wings level, and pull really, really hard. If the flight control system will let you apply full-up elevator regardless of the angle of attack or g, the outcome could be that you hit the water wings level, nose up, and at a relatively low forward speed but with an unsurvivable rate of sink.

ZeeDoktor

OK, , that makes sense, though wouldn't a spin by itself produce the postulated impact geometry (i.e is an aircraft rotating in a deep stall simply spinning in the classic sense of the "spinning" word) ?

It depends how you define "deep stall". For some it just means an AoA substantially greater than that at which the stall first manifests itself. The T-tail problem is the airplane being "locked-in" in that condition.

As far as I am aware, no one on this thread really knows how the airplane was certificated in this respect. Some contributors, for example PBL, on the basis of a literal interpretation of the relevant regulations, have suggested that an investigation of its stalling characteristics beyond "alpha max" was not required, by virtue of the AoA protections incorporated in its flight control system in "normal law".

That said I should emphasize that without further evidence, all talk about stall, deep stall, superstall, flat spin, etc. in relation to AF447 is just speculation and, IMHO, not the most likely scenario of what happened.

regards,
HN39

Tailspin turtle, only two problems with that scenario. One, there was no lightning with this particular complex; none detected by satellite, nor by ground stations. Apparently lightning is infrequent in the ITCZ. Two, the moon was behind them.

http://www.weathergraphics.com/tim/a...1.2009.152.gif

A LH 744 on the same track saw no lightning, but did have St. Elmo's fire.

Also,
http://www.cloudsat.cira.colostate.e..._1AA_small.png

http://www.cloudsat.cira.colostate.e...A_large_31.png

http://www.cloudsat.cira.colostate.e...ctivity_31.png

Source:
http://cloudsat.cira.colostate.edu/d...04_E00_1AA.htm

click on segment 31 for the radar profiles of the mesoscale convective complex.

I like this quote from D.P. Davies regarding "superstalls".

The quote seems very relevant to AF447.

HN39 quote:
In the vicinity of alpha max I would expect predictable stall behavior.
Well beyond alpha max, I would expect stall characteristics approaching those of a swept wing flat plate airfoil-in other words, terrible.
That work-of-art Airbus airfoil, optimized for cruise, was probably never even tested well past alpha max. I expect that the Airbus AOA protection system was considered to be better than a stick pusher and thus sufficient to prevent flight outside the design flight envelope.
Somehow, AF447 exceeded its design envelope, and that is the question which the information from the black boxes needs to answer.
It may well be more complex than pitot icing. Let us hope that the information is still available.

Machinbird;

Terminology surrounding a deep stall can be confusing, but D.P. Davies' quote puts it all into context. Once you get there, there is probably no way out (without a tail 'chute).

ZeeDoctor,

Keep in mind that your basic swept wing tends to tip-stall first. This causes a shift in center-of-lift forward and my understanding is that therefore swept wings are inheritantly more succeptable to deep-stalls than straight-wings. I don't know what kind of protections modern transport category aircraft have to prevent this but any computerized protections for AF447 were believed to be unavailable.