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AF447

Old 2nd Jul 2009, 14:37
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deSitter:
Upshot - BEA say it did not break up in flight but entered the water vertically at high speed.
Absolutely incorrect:
"L'avion est entré au contact de l'eau en ligne de vol avec une forte acceleration verticale"

Meaning:
en ligne de vol = horizontaly (not verticaly)
+ acceleration verticale = stalled

No mention of the global impact force from the conference, I need to read the report. But no surprise from the press headlines, it was too technical to be understand rightly (certainly inacurately translated). I have watched the conference on TV.

Last edited by Jetdriver; 26th Jun 2011 at 11:19.
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Old 2nd Jul 2009, 14:40
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takata, I am quoting verbatim from the english tranlsation of the briefing I was just watching on CNN, repeated twice - the plane entered the water vertically (same word in French, impossible to mistranslate I assume - I could not hear the French commentary).

-drl
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Old 2nd Jul 2009, 14:40
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VS detached from back to front

Mr Bouillard said that the vertical stabilizer is likely to have detached from the back to the front with a slight movement to the left.
Aircraft touched the ocean in a state of flight with a strong vertical acceleration
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Old 2nd Jul 2009, 14:43
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takata - "ligne de vol" is direction of flight - "acceleration verticale" means just what is says.

"L'avion est entré en contact de l'eau en ligne de vol avec une forte acceleration verticale" - The airplane made contact with the water on a line of flight with a strong vertical acceleration. I suppose this could be considered ambiguous by some. There is no report posted on BEA website yet.

-drl
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Old 2nd Jul 2009, 14:46
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Squabble, Squabble, Squabble - we're off again. It is UNBELIEVABLE! Bar a few posters, no-one appears capable of getting anything right on this thread

Shall we wait for the official statement, (translated correctly into English?)....and as for quoting CNN
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Old 2nd Jul 2009, 14:48
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deSitter:
takata - "ligne de vol" is direction of flight - "acceleration verticale" means just what is says.
Thank you for explaining me what it means in my mother tongue!
"Ligne de vol" is attitude of flight, not direction. Even French people without aviation understanding (e.g. translators) may be confused, but it is the meaning.

S~
Olivier
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Old 2nd Jul 2009, 14:50
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BOAC - no one is "quoting CNN", I was repeating VERBATIM the words of the running English translation of the live briefing.

-drl
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Old 2nd Jul 2009, 14:51
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Sleepypilot

I didn't mean a diversion for weather,of course,but diverting to an enroute AIRPORT for landing...!!
In this particular case the Capt. got a wake-up call in the bunk when nearing the (new) tod..
Have a nice nap,chap

Wilbur
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Old 2nd Jul 2009, 15:04
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The last ACARS transmission was received at 02.14.28 (UTC time)
No FPL transmission was received by Dakar although Atlantico had a telephone call to Dakar with the element of AF447.
At 02.01 a contact through ADS (Air Data System) was attempted by the crew to join Dakar
Part of radar protection "radôme" and engine(s) protection were recovered.
No life jacket were found inflated
It seems that only Madrid and then Brest Control started to worry near 0800/0830 (local)

Up till the 10/07 BB signal may be received. After the 14/07 other means should be used (??)

Last edited by Squawk_ident; 2nd Jul 2009 at 17:26.
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Old 2nd Jul 2009, 15:10
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I have read this thread with interest and hesitated to post but now that the subject of "dry thunderstorms" has been raised, I'll make a small contribution.

Most of my career was spent flying in the northern hemisphere, a lot of it fairly far "north" at that. Towards the end of my 20K hours my employer began routes across the ITCZ and after some long chats with a friend with extensive experience there, I was very concerned about running into a CB which did not paint on the radar in the dark. He talked of using NVGs and various radar techniques to avoid such an event.

A couple of points, first I always made certain that I was in the cockpit during the ITCZ phase of flight - the bunk was not an option. Second I learned from other pilots that there were some creative ways to use the radar to detect CBs that would otherwise go undetected due to the lack of moisture. I won't go into them here, mainly because memory has caused details to fade, the point is that the use of radar is not an exact science - experience and technique is crucial. And that may well have been a factor in this accident.

I think I was as close to the edge of my seat transiting the ITCZ as I ever was during a CAT III approach to an icy runway.

Edited for format.
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Old 2nd Jul 2009, 15:11
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With differing translations I think we need to wait for the official one!

Air France jet 'broke on impact'




French investigators trying to find out why an Air France plane crashed in the Atlantic say they believe it broke up on contact with water, not in the air.
They said they reached that conclusion after examining the plane's wreckage.
All 228 people aboard the plane were killed when it plunged into the ocean en route from Rio de Janeiro to Paris on 1 June.
Teams looking for the plane's flight data recorders will continue operations for another 10 days, an official said.
Alain Bouillard of the investigating team said the plane probably hit the water belly-first.
He said the plane "appears to have hit the surface of the water in flying position with a strong acceleration".
The investigators also said that faulty speed sensors, which were suspected of being behind the crash, had been "a factor but not the cause".
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Old 2nd Jul 2009, 15:17
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Hmm, the "impossible" flat spin of a jet transport.
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Old 2nd Jul 2009, 15:19
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I appreciate the translation problems. But, if the plane ''landed on its belly'', can we think that the crew made an effort to land upon the water (ditch)?

could the plane have stalled, lost a massive amount of altitude and had its engines quit, recovery at the last second (albeit with a high rate of descent...vertical acceleration) and the crew tried for a landing?

I think we will never really know what happened without the CVR/FDR.

----

also wondering if the plane was spinning at time of impact...could plane have come down in a flat spin?
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Old 2nd Jul 2009, 15:24
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Takata, attention !!!!!!!
Absolutely incorrect:
"L'avion est entré au contact de l'eau en ligne de vol avec une forte acceleration verticale"

Meaning:
en ligne de vol = horizontaly (not verticaly)
+ acceleration verticale = stalled
That's a very fast conclusion, to which, I for one do not subscribe.

Actually,
He said the plane "appears to have hit the surface of the water in flying position with a strong vertical acceleration".
(stress by me)
is a lot more correct.
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Old 2nd Jul 2009, 15:32
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.
I was merely explaining that it is not sufficient to divide (catastrophic events) by (fleet flight hours) in order to verify the probability of an event.
"The probability of an event" is not a well defined concept. You need to ask a specific question, then use historical data appropriately to get a quantitative answer.

Dividing the number of catastrophic events by the number of fleet flight hours gives you the answer to the question "What is the probability that an A330 will experience a catastrophic event in any given hour chosen at random from a spectrum of flights similar to those the fleet has undertaken so far?"

This number wouldn't be appropriate, for instance, to figure out the probability of a catastrophic event in a flight that routinely experienced severe turbulence (by which I mean turbulence like the AF flight encountered - I may have the terminology wrong), because the underlying sample of flights is not representative of that situation. For that, you should ask how many A330s encountered severe turbulence to date and use that as the base population.

However, if the question is "should we ground all A330s today?" dividing the catastrophic incidents to date by the total flight hours to date is not an unreasonable way to gain a quantitative piece of information.

Insofar as long haul aircraft probably all fly roughly the same spectrum of routes, there doesn't seem much evidence that the A330 is more dangerous than the others. One question would be "why ground just that one?"
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Old 2nd Jul 2009, 15:42
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Clarifying the Static Pressure Locked scenario

ref Takata's post 2694
As for the pernicious contamination from the ground, I do not share your point because:
1. the system reacted and disconnected the flight envelope protections, showing that it was an abrupt change of air data stream at 0210.
2. the flightpath doesn't show any acceleration of F-GZCP during her whole flight.
3. GPS altitude could be used to control Indicated altitude at any time.
4. Your premise being "loss of control between 0210-0214" is based on nothing acertained until now; this is by far not the only possibility behind this catastrophe.
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)
.
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.
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. 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.

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.
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Old 2nd Jul 2009, 15:45
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Speaking as an SLF i think this defines the conundrum and the appropriate path of action very nicely...

"One either submits to the designer's and engineer's intentions or as a professional aviator one draws a firm line over which the engineer is not permitted to cross. Hand-flying isn't "practise" - it is the finest way to maintain situational awareness. It is a human-factors defence activity which necessarily requires thinking and the attention of everyone."

I think in the end the effect of automation on the pilots ability to aviate under conditions of extreme duress goes to the heart of the matter. In my mind the thousands of hours a senior captain acquired hand flying under stress (arrival/departure in traffic, takeoff/approach in adverse weather etc) mentally prepared him for the unexpected. The more complex the mental aspects of "normal" flying the easier to transition to handling a truly catastrophic event (while a sim will help your preprepared since you know something will go wrong).
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Old 2nd Jul 2009, 15:52
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Well, still a way to go on the 'announcements' it would seem. Original translation now amended.
Crash: Air France A332 over Atlantic on Jun 1st 2009, aircraft impacted ocean
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Old 2nd Jul 2009, 16:05
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AF 447 preliminary report

http://www.bea.aero/docspa/2009/f-cp...cp090601e1.pdf
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Old 2nd Jul 2009, 16:07
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Report is published

http://www.bea.aero/docspa/2009/f-cp...cp090601e1.pdf

In English

http://www.bea.aero/docspa/2009/f-cp...90601e1.en.pdf

Last edited by Squawk_ident; 2nd Jul 2009 at 16:26.
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