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AF447

Old 2nd Jul 2009, 16:14
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Thanks for the effort, DB, but I think there is either a problem with the link or access is restricted?
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Old 2nd Jul 2009, 16:17
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It takes a while to download. The pdf version is 128 pages.
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Old 2nd Jul 2009, 16:19
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Link to english version

For me the link works fine, BOAC even clicked from my post.

It's a heavy document though (> 11MB and 126 pages and of course in French....)

But here is the BEA page with a link to the english version which, surprise, surprise, is "only" 72 pages (I'll look for the differences though it may take a bit of time....)

News

Direct link:
http://www.bea.aero/docspa/2009/f-cp...90601e1.en.pdf
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Old 2nd Jul 2009, 16:19
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Crash: Air France A332 over Atlantic on Jun 1st 2009, aircraft impacted ocean
By Simon Hradecky, created Thursday, Jul 2nd 2009 13:11Z, last updated Thursday, Jul 2nd 2009 15:16Z
The BEA has concluded their press conference introducing the results of their investigation and their preliminary report so far.

The key sentences have been (according to simultaneous English translation by BEA):

- No technical problems with the airplane before the takeoff.
- The airplane did NOT break up in flight.
- The 24 ACARS messages refer to the loss of airspeed (pitot tubes)
- The airplane also lost information about the direction the airplane was going to.
- The airplane hit the ocean in a flat attitude at high vertical speed.
- Weather was a classic ITZ scenario.

Nothing had been found before June 6th, then the first bodies and parts have been found. Parts from the nose to the tail of the airplane have been found including parts of the structural body of the airplane, one part of the engine and parts of the main cabin have been recovered. No clothes have been found, recovered life vests were not inflated. 51 bodies were recovered.

One of the cockpit walls has been found deformed. A large part of the crew rest room has been found, impact marks indicating that something came from the bottom up to the top. The debris recovered so far suggests, that the airplane did not break up in flight, but went down vertically.

Three other flights (IB-6024 [A343, Rio De Janeiro GIG-Madrid MAD 12 minutes behind AF-447], LH-507 [B744, Sao Paulo GRU-Frankfurt FRA] 20 minutes behind AF-447, AF-459 [A332, Sao Paulo GRU-Paris CDG 37 minutes behind AF-447]) tracked the route ORARO to TASIL between FL350 and FL370 around the time of the crash. They all had to avoid storm cells and diverted from the airway between 11 and 80nm. They experienced moderate turbulence. All three flights had problems to establish communication with Dakar. There were no satellite phone conversations from those crews.

The weather in the Intertropical Convergence Zone was a classic scenario with storm cells.

The airplane had started the engines at 22:10Z and got airborne at 22:29Z. Last radio communication was at 01:35Z. No transfer had been completed from Rio's control to Dakar control. An attempt by the AF-447 crew to establish contact with Dakar Control has been detected at 02:01Z (the wording to the means of communication was unclear, supposedly it was a digital data transmission via ACARS). No distress call was detected.

First alerts were sent at around 8:30 (unclear whether GMT, local Europe, local Brazil).

The BEA refuses to believe, the black boxes would not be found, however stated, that the search for the recorders will be terminated on July 10th.

The Original BEA English translation said: The airplane went down vertically, a review of French wording offers a different picture however stating, that the airplane came down in a flat attitude at high vertical speed.

The full preliminary report has just been published:
French Version (13MB) and English Version (3MB).
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Old 2nd Jul 2009, 16:22
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Dagger Dirk:
I think that UNCTUOUS was inferring that the water present in the static lines froze and expanded in the lines at height - blocking the static line and locking in the static pressure. That can happen as a function of:
a. water pooling (flowing from another area after the climb and due to angle of incidence in the cruise)
b. thermal soak (cooling time - explaining why it took around 3 hours)
Ok, why not but suddendly like that? And once it is frozen, after around 3 hrs, why would the static lines just became clean all together after few minutes, and why maintenance would not discover any problem (beside the pitot-probes) once grounded?

I'm much more prone to believe that this is an explanation in order to twist the sequence and legitimate the following:
.
If, in consequence, the sudden ADIRS disagreement precipitated an autopilot disconnect, then it's possible that a loss of control ensued (due to Alternate Law coupled to heavy handed inputs at a height at which pilots aren't used to hand-flying anyway). Very few pilots would have hand-flown at FL300 and above.
Well, at FL350, the aircraft is flying level and all Airbus are flown in direct law without much trouble (ask Lemurian, it is like a 737). They have even been certified like that, before introducing the various level of fligh envelope protection. Not a single report from any previous freezing incident included the quote: "we were left with an uncontrolable aircraft impossible to be hand flown because A/THR and AP disconnected"...

If pitch protection is still in force in Alternate Law, during an upset it may well work AGAINST a successful recovery. Anybody who's practiced unusual attitudes knows that once a jet's nose drops significantly below the horizon at speed, you are then battling to not exceed VNE/max Mach by a wide margin.
Here is the main point. But sorry, pitch protection disengaged in ALT2. Moreover, we already know the altitude (FL350) and speed (cruise) at 0210, it was sent by the positional report few secs before the first ACARS. The aircraft wasn't at all in an uncontrolable attitude at this point.

Success there is tied to generating drag via g, after (but not whilst) rapidly finding wings level then pitching back up to the horizon (and using idle thrust/speedbrakes to control the rate of speed increase). All this depends upon having a valid attitude source. If you don't, then the LOC becomes terminal due to disorientation. If pitch protection affects the rate at which you can pitch, then likewise you are probably going to exceed VNE by a VERY wide margin.
Sure, but nobody previously lost control, just maintained pitch and power and waited until the speed come back. In your scenario, the aircraft is starting to break appart... but, sorry, she didn't and it is now confirmed as a fact. Moreover, the area searched so far was a 80 km circle around her last position and they didn't found any wreckage at the botom of the sea. => she didn't crashed around this point.

That's what likely happened in the 4 minutes immediately prior to the final ACARS msg. Any less rapid a sequence would have permitted at least a Mayday call to have been transmitted.
Who told you that they didn't tried to transmit a Mayday?
Nobody heard from them on radio/statelite. Their last contact with Brazilian ATC (0145 and few secs). Then, the tried, without success, to contact Dakar at 0201 (the call was logged). Dakar ATC wasn't informed of AF 447 flight plan from the Brazilian ATC... go figure, it takes the Spanish ATC to give an alert at 0615 utc. Moreover, the BEA presented the fact that the closest aircraft (AF, IB, LH) had all experienced transmition problems in this area at the same time. None were able to use their VHF.
ACARS are relying on SATCOM. There is plenty of reasons why SATCOM could stop transmiting. One is a double engine failure (e.g. engine icing or stalled if they lost control).

Last point from the BEA conference: they underlined that nobody recieved any AF 447 report of "strong turbulences" during this flight. The 0145 ATC contact was her last. Neither ATC or Air France (as I suspected it from the first Air France conference) recieved anything.
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Old 2nd Jul 2009, 16:24
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GB;
Hmm, the "impossible" flat spin of a jet transport.
Ouch.

Not impossible, merely improbable given possible entry into a thunderstorm.



One thing flight safety investigators and specialists don't do is hitch their wagon to theories and stick with them in the face of new evidence. I would have thought (and did) that, as the impact is described, a high-speed vertical trajectory in a flat attitude/spin, (indicating a very high angle of attack), would have resulted in greater evidence of a) compression stress and b) evidence of shattering of parts instead of large intact structures but there it is.

How this conclusion was reached will be revealed in the coming days/weeks but at least we know more now and it will be fascinating to learn how this was concluded.

Last edited by PJ2; 2nd Jul 2009 at 16:34.
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Old 2nd Jul 2009, 16:28
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The aircraft did not break up in flight
Well I would like to believe that, but without benefit of CVR/FDR, just how did BEA establish this "fact"?
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Old 2nd Jul 2009, 16:34
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The English version is 55 pages shorter and looks to be minus the annexes.
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Old 2nd Jul 2009, 16:34
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During the Press Conference the BEA stated that they would "listen" for the CVR and FDR for another 10 days and then they would continue the search with another method (sonar?) "until these units were found"
It was also stated that the aircraft impacted the sea tail first slight bank to the left and almost flat. This conclusion reached from evidence on the VS, which was torn from the fuselage aft to forward, the galley tray damage and pieces of the cabin floor which were bulged upwards. It was also stated that the A/C accelerated to the surface of the sea. He also stated that the A/C did not call Senegal and three other aircraft crew interviewed, who flew the route within 30 mins of AF447, had encountered moderate turbulence and had diverted from 10 to 80 kilometers from course to minimise the impact of this. These A/C also heard nothing from AF447. The pitot problems were stated to be "involved in the incident but not the sole cause" No sign of the presentation being posted on the net as yet.
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Old 2nd Jul 2009, 16:48
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Well I would like to believe that, but without benefit of CVR/FDR, just how did BEA establish this "fact"?
By engineering analysis on the wreckage, much is known about structural deformation and they can accurately tell how the aircraft came apart.

They can specify facts without the FDR/CVR's.
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Old 2nd Jul 2009, 16:56
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PJ2


One thing flight safety investigators and specialists don't do is hitch their wagon to theories and stick with them in the face of new evidence. I would have thought (and did) that, as the impact is described, a high-speed vertical trajectory in a flat attitude/spin, (indicating a very high angle of attack), would have resulted in greater evidence of a) compression stress and b) evidence of shattering of parts instead of large intact structures but there it is.

How this conclusion was reached will be revealed in the coming days/weeks but at least we know more now and it will be fascinating to learn how this was concluded.
Well I thought that you and others had got it mostly right. I had interpreted the largely intact parts as being from a flat low forward speed impact with the water and the recovered parts significantly protected from severe damage by the hydraulic crushing of the planes underbelly.

The only evidence of hydraulic crushing that I might have recognized was the bottom of the crew rest module in the belly (I had pointed to this earlier as of interest).

Of course the crushed metal fragmentated pieces would have sunk.

I like you will be interested on their change of opinion from their earlier comments about it breaking up in the air to the supposedly new comments about it being intact in their latest release.

I hestitate to form an opinion based solely on the reports in the news (I don't trust their interpretations or translations). However I do look forward to this board's interpretations since we have enough divergence of experiences to not miss the more subtle stuff
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Old 2nd Jul 2009, 17:00
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Given this has been the subject of some interest:

Co-pilot #1:
Airbus A330 type rating issued 1st October 2002
• Line oriented flight training completed 25 October 2002

Flying hours:
o total: 6,547 flying hours
o on type: 4,479 flying hours

Co-pilot #2

Airbus A330 type rating issued on 1 December 2008
• Line oriented flight training completed 22 December 2008

Flying hours:
o total: 2,936
o on type: 807
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Old 2nd Jul 2009, 17:14
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PJ2:
One thing flight safety investigators and specialists don't do is hitch their wagon to theories and stick with them in the face of new evidence. I would have thought (and did) that, as the impact is described, a high-speed vertical trajectory in a flat attitude/spin, (indicating a very high angle of attack), would have resulted in greater evidence of a) compression stress and b) evidence of shattering of parts instead of large intact structures but there it is.

How this conclusion was reached will be revealed in the coming days/weeks but at least we know more now and it will be fascinating to learn how this was concluded.
Well, the vertical part on the report is "high vertical acceleration" (observed in recovered objects relative to their horizontal position in the airframe), this mention quoted of "high-speed vertical trajectory" just doesn't exist in the report. There is nothing on it to deduct a flat/spin right now. I guess that any ditching would cause a fair amount of "high vertical acceleration" depending of the aircraft pitch when the cabin hit the water.

I'm still reading the report, it is fairly long and detailed.
S~
Olivier
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Old 2nd Jul 2009, 17:20
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From the English Version:
1.12.2 Identification of the items recovered
The identification of the debris shows that it consists mainly of light items belonging to the cabin fittings and holds (bulkheads, galley, ceiling or floor panels, seats, overhead baggage bins, cabin and hold lining).

Approximately thirty pieces are external parts of the plane (vertical stabiliser, pieces of the radome, the engine cowl, the under belly fairing, the flap actuator fairing, the trimmable horizontal stabiliser and the secondary control surfaces). The identified debris thus comes from all the areas of the plane.

An ELT distress beacon with manual tripping was also recovered. This had not been actuated. Its switch was found in the “OFF” position.

1.12.3 Visual inspection
A first visual inspection brought to light the following.
The tail fin was damaged during its recovery and transport but the photographs available made it possible to identify the damage that was not the result of the accident. The middle and rear fasteners with the related fragments of the fuselage hoop frames were present in the fin base. The distortions of the frames showed that they broke during a forward motion
with a slight twisting component towards the left.

Part of the radome was found, representing approximately a fifth of its circumference along its upper part.

The galley, identified as G2, located at the level of door 2 on the right-hand side, was not very distorted. Baskets and racks were compressed in the lower part of both galley carts.

The distortions observed in the metal vertical reinforcements of a toilet door showed evidence of great compressive forces

Fragments of the walls of the flight crew rest module were crumpled and those of the ceiling were deformed downwards. The floor was curved under the effect of a strong upward pressure from below. The connecting brackets between the floor and the walls were bent backwards.

1.12.4 Summary of visual examination
Observations of the tail fin and on the parts from the passenger (galley, toilet door, crew rest module) showed that the airplane had likely struck the surface of the water in a straight line, with a high rate vertical acceleration.

1.13 Medical and Pathological Information
Sailors from the Frigate Ventôse recovered about thirty bodies. A visual examination of the bodies showed that they were clothed and relatively well preserved. All of them were handed over to the Brazilian Navy to be transferred to the Recife morgue. At this stage of the investigation, the BEA has not yet had access to the autopsy data
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Old 2nd Jul 2009, 17:21
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One of my ground school instructors had been accident investigator in the USAF. He said victims of a flat spin were intact in their seats, just dead.
A gross appproximation maybe! The tell-tale would be as in the LHR Staines accident, yes 'likely' to be still strapped in, but with compressed verterbae almost uniformly.

Look, there's a whole host of people here, maybe pilots maybe not, but this is engineering and kinematics stuff, or a lot of it is... accident investigation - certainly impact dynamics is NOT necessarily just about flying and piloting knowledge, unless so many have had a lot of accidents & walked away... there's opinions flying about like wasps in a jam-jar here, and that's all most of them are, 6 possibilities back ther in ONE post!!

We need to take deep breath... and let some experts think this through a bit.

====

For what it is worth, 'high acceleration' an engineer usually means in this context... a/c arrived with large deceleration upon impact e.g. it was travelling fast & stopped very quickly.

High acceleration is just they way it is said... inplying large forces.

I also interpret the previous line to mean the trajectory was predominantly vertical but the attitude was predominantly horizonatal (line of normal flight)

In fact much as takata said...
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Old 2nd Jul 2009, 17:23
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What doesn't quite sync is that we are told that the VS broke off with pressure from back to front, yet also that the ac hit the water flat ?.

Looking at the photos of the VS and what must have been the considerable force involved in it's separation, how could this have happened aka the reported scenario ?. All the leverage would be in the wrong direction.
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Old 2nd Jul 2009, 17:25
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jehrler;

Sorry, should have titled it- it is an amateur photo taken of the BOAC 911, B707 which broke apart mid-air due turbulence over Mt. Fuji on the 5th of March, 1966; the information on the web indicates that the tail broke off towards the end of the vertical, flat-attitude descent; the photo illustrates what many would call a "flat-spin" but I would characterize as a "brick" because the airplane isn't "spinning" in a way most think of as a spin. The main factor is, the airplane is fully stalled; you can see the "lumpy", turbulent air above the wings, made visible possibly by the vaporizing fuel pouring from the wings or condensation caused by the very low pressure above the wings as "the brick" fell vertically. Bit clinical I know, but those are the dynamics.
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Old 2nd Jul 2009, 17:28
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Well I would like to believe that, but without benefit of CVR/FDR, just how did BEA establish this "fact"?
Easily. Compression. It says so in the (english) report. Certain parts that were recovered and, according to the report, were compressed as the floor came up and the ceiling stayed where it was (compressing things there too). That would never happen with the aircraft breaking up in mid air (and, realistically, I would reckon there would have been more debris found if it had) as the compressive forces, on different parts of the aircraft from nose to tail, as various bits would have hit at a different speed so wouldn't have a "uniform" compression.

Two bits to pull out of the report...

Recovered bodies were fully clothed...... Can we stop all the speculation of clothes being ripped off as the aircraft fell apart at 35k?

VS broke off in a FORWARD direction......... I do hope that was a mistranslation.
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Old 2nd Jul 2009, 17:33
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Looking at the photos of the VS and what must have been the considerable force involved in it's separation, how could this have happened aka the reported scenario ?. All the leverage would be in the wrong direction.
It's possible the aircraft could have been somewhat tail-down & travelling backwards at time of impact - though fundamentally descending vertically..

Have you heard of a 'falling-leaf' mode.. of course you have, the body is shuttling between 2 or 3 different modes of descent, first backwards and then flipping and travelling forwards.

The HS tail & wings would have broken off too, and the fuse into parts as well either side of the centre-section probably, but of course, the VS is positively buoyant and came back up.

I agree breaking off forward is what in the US they call 'counter-intuitive'

I believe the damage to the lower rudder area might be one piece of evidence that has produced this conclusion, but not the only one. In fact , if so, this shows what an incredibly strong structure the VS is...
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Old 2nd Jul 2009, 17:42
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HarryMann;
We need to take deep breath... and let some experts think this through a bit.
Yes, exactly.

One thing this new information affords, if correct, is, the location of the impact point can be more closely approximated using the kinds of techniques we have seen described working backwards from where the vertical stab was located.

If this new assessment of the condition of the aircraft's descent and impact is true, the recorders will not have been ejected as projectiles at some point at high altitude but will be within a smaller radius of the yet-to-be-determined point of impact of an intact airframe, deep-water ocean currents notwithstanding.
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