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AF447

Old 7th Jun 2009, 20:34
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The least significant parts of this survey are most probably inner linings, but as they are made of honeycomb structure, including air, they seem to be retrieved first while floating along:
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Old 7th Jun 2009, 20:39
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The second Press release from AF:

1 juin "...L'appeireil a traverse une zone orageuse avec 'fortes turbulences' a deux heures du matin (heure universelle)..."

the a/c traversed a zone of thunderstorms with strong turbulence at 0200 universal.

pardon my French.

Last edited by Will Fraser; 7th Jun 2009 at 20:51. Reason: spagiola correction, merci
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Old 7th Jun 2009, 21:16
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OK, if the AF 447 "hard turbulence" story originated with an AF press release, then it's useful to note that the press release says nothing about how AF got that information; i.e., nothing about getting a voice or text message direct from AF 447 itself.

Here's the link to all the AF press releases:

Communiqués de presse

As other have said, the only mention is in Release #2 (scroll down the page, as they are given in reverse order):

Air France a le regret d’annoncer la disparition du vol AF 447 effectuant la liaison Rio de Janeiro – Paris-Charles de Gaulle, arrivée prévue ce matin à 11h10 locales, comme vient de l’annoncer à la presse le Directeur général d’Air France, Pierre-Henri Gourgeon.

L’appareil de type Airbus A330-200, immatriculé F-GZCP, a quitté Rio le 31 mai à 19h03 heure locale (00h03 heure de Paris).

L’appareil a traversé une zone orageuse avec fortes turbulences à 2 heures du matin (heure universelle), soit 4h00 heure de Paris. Un message automatique a été reçu à 2h14 (4h14 heure de Paris) indiquant une panne de circuit électrique dans une zone éloignée de la côte.

L’ensemble des contrôles aériens civils brésilien, africain, espagnol et français ont tenté en vain d’établir le contact avec le vol AF447. Le contrôle aérien militaire français a essayé de détecter l’avion, sans succès.
The third para is:

"The aircraft crossed an area of storms with strong turbulence at 2.00am (universal), or 4.00am Paris time. An automatic message was received at 2.14 am (4.14am Paris) indicating a failure of an electrical system in an area far off the coast."

AGB

[later note: AF have an English-language version of their Press Releases:

Press Releases

The translation above was mine. The official one is:

The aircraft hit a zone of stormy weather with strong turbulence at 2am this morning (universal time), i.e. 4am in Paris. An automatic message was received from the aircraft at 2:14am (4 :14am in Paris) indicating a failure in the electric circuit a long way from the coast.
]

Last edited by Gary Brown; 8th Jun 2009 at 13:37. Reason: Added link etc to official AF English-language site]
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Old 7th Jun 2009, 21:31
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With the recovery of 6 bodies I would say it's becoming clear, because of the art of forensic science, to investigators how the aircraft came down.

Maybe some of the speculation should rest for a short time now as I'm sure they will release a statement in the next few days to this effect, and then work on the reasons why it happened.

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Old 7th Jun 2009, 21:32
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@AGBagb:

Thank You for searching. During this week several of my posts pointing to the fact that there is nothing indicating a msg about turb from AF447 at 0200UTC have been deleted.

I find some inconsistencies on the speed calculations that could indicate that they were flying faster than they thought, beeing 260 KIAS the penetration speed. I could imagine a slow build up of ice in the sensors, in the beginning uniformely and thus not detected. If You hit moderate turb in this config?????

Last edited by Flyinheavy; 7th Jun 2009 at 21:42.
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Old 7th Jun 2009, 22:20
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Interflug writes:
So if the weather reports of ISA+38 in the storm cell are true and AF447 was flying at FL350 into the "pool of warm air", what would be the result?
Someone has posted in the thread in Tech Log a reply from Tim Vasquez on precisely this question.

"I have asked Tim his opinion on the likelihood of temps within cells climbing with 30 degrees within seconds, and below is his reply:"

I do not agree that a bubble of warmer air (that is, any warmer than about 5 degrees compared to the environmental air) would have made it up to flight level.

This requires exceptionally high equivalent potential temperatures at some lower altitude. The atmosphere has a tendency to overturn bubbles of hot air as soon as they
start becoming significant because "absolutely unstable" lapse rates are unsustainable.

We do see thunderstorm heat burst phenomena on the Great Plains at night, but this occurs due to the downward forcing of a low-level inversion, and I can't picture a mechanism for this to occur at flight level given the conditions shown.

But in regard to the above mention of an aircraft's "coffin corner", it is possible that wind values alone could greatly affected airspeed -- on Doppler radar we often see anomalies of 40 to 80 kt at flight level within storms (Google "storm top divergence" for some examples).

Tim
Tim Vasquez has posted a weather analysis for the AF744 which has been widely reported. His reply to this question is NOT on his website at this time.

HTH

FBW
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Old 7th Jun 2009, 23:01
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Bubble of hot air

Tim Vasquez did an outstanding job, I've read his report, but :

""Flying from Buenos Aires we overflew Rio de Janeiro and followed the same route that AF474 was flying when the accident happened. Crossing the ITCZ at FL370 with moderate to heavy turbulence in a 1-2 minutes period we experienced a sudden increase in air temperature, from -48ºC to -19ºC."
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Old 7th Jun 2009, 23:09
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Brazilian Air Force - Rebutal of ATC Critics

About 4 hours ago the following appeared on FAB website, but has since been withdrawn. The translation is per Google and actual interpretation will be up to individuals.

07/06/2009 - 15h02
Clarification 07/06/09 - Air Traffic Control (Times Magazine)
Regarding the report "A blind spot in the ocean", published by Vintage (8 / 6), the Center provides the following clarification:

1) The crossing of oceans in the world is done through a specific air traffic control, supported in commercial radio, because there is no way to build a network of radar coverage there. In an irresponsible manner, the matter ceases to contextualize it. Aircraft fly in different conditions from those that cross the continent;
2) Communications between the Brazilian air traffic control and flight 447 operated correctly, as intended, proof the contact made to 22h33, radio, with the Area Control Center Atlantic (CINDACTA III) in position INTOL (565 km Christmas RN), indicating that enter the airspace of Dakar - Senegal (position TASIL - 1,228 kilometers from Natal RN) at 23h20 (schedule of Brasília);
3) The aircraft was accompanied by Brazilian radars until the last available equipment on the island of Fernando de Noronha, when it flew above the Brazilian coast, in the open sea. That to 22h48;
4) On the coverage by satellite, known as the Brazil part of the select group of nations that is ahead of the system that will revolutionize the control of air traffic in the world with the establishment of airspace continuous (CNS-ATM). This system, in English, meet the following: Communication (C), Navigation (N), Monitoring (S) and Air Traffic Management (ATM);
5) The CNS-ATM system has not yet been implemented anywhere in the world;
6) It is worth mentioning that in the recent audit of the International Civil Aviation Organization (ICAO), the service provided by the Department of airspace control Brasileiro (DECEA) was evaluated as one of the five best in the world;
7) The report ignores the result of technical research on the accident flight 1907, released last year after more than two years of work and that made it clear that the radar coverage in Brazil was not contributing factor to this occurrence. This failure to report puts readers on the understanding of security in the country;
8) It is vital for the country handle the issue "and aviation security" and released without emotion of private interests. It is prudent, therefore, that any debate is marked by terrorism information, the simplification of examples, with the handling of comparisons, using data out of context and under the influence of personal claims.

Source: MEDIA CENTER OF AERONAUTICS

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Old 7th Jun 2009, 23:39
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I was crossing the ITCZ a few years ago at FL390 and flew into a green radar return. The OAT before entering was -56C. In a few seconds it had risen to -28C. We received a message from out FMC that we were cruising above Max Flight level. The ride however was smooth and the aircraft, a 767, coped well. Flying out of the cloud brought an instantaneous reduction in Temp back to -56C.
Tim Vasquez may be a fine meteorologist, but he doesn't know everything.
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Old 7th Jun 2009, 23:47
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Black Box Question

Forgive my ignorance but, shouldnt the black boxes be positioned in an area of the airplane that somehow once there is an accident could they sort of be released by design onto safe ground and furthermore enclosed in well engineerd floating covers. It seems to me that this is technologically feasible.
Hernan herman, you question is a good one and you will find that there are some Flight Data Recorders which are designed to use the "kinetic" energy of a crash to be propelled away from the crash site, (althogh having a FDR land on you head would finish you off even if the crash did'nt!), newer FDR's are programmed with homing signal transmitters that will send a signal for up to 30 days, however thats if the force of the crash has not damaged the system.
If you read what French avaition officials have been saying they believe the aircraft may be in up to 12,000 feet of water & no FDR has ever been recovered at such a depth, whilst they are built to "take a licking & keep on ticking" the pressure at such depths may well have shattered the casing & rendered the information unreadable.
Google Flight data recorder for a better understanding of how it works.
Hope this helps.
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Old 7th Jun 2009, 23:48
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Someone has posted in the thread in Tech Log a reply from Tim Vasquez on precisely this question.

"I have asked Tim his opinion on the likelihood of temps within cells climbing with 30 degrees within seconds, and below is his reply:"

Fly-By-Wife, would you please provide us the link of the mentioned thread in Tech Log?

Regards
Sergio
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Old 8th Jun 2009, 00:05
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Hands On Confidence

All of you pilots who now fly around confidently using predominantly push buttons and switches need to give thought to your confidence in being able to handle a hands on situation with your aircraft close to coffins' corner with some turbulence and system failures thrown in for good measure.
What percentage of hands on flying have you done lately?
How well do you know the manual handling of your aircraft at the corners of the envelope?
We TPs creep up to the absolute limits of those corners with some trepidation.
Are our margins too narrow?
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Old 8th Jun 2009, 00:26
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Originally Posted by SergioR

Fly-By-Wife, would you please provide us the link of the mentioned thread in Tech Log?

Regards
Sergio
http://www.pprune.org/4981351-post37.html

FBW
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Old 8th Jun 2009, 00:42
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Regarding sudden temperature increase in cruise have had same experience in anvil cloud at FL 370 over South China Sea. Sudden temperature increase in SAT from -53C to -30C and moderate ice accretion ,with very little turbulence experienced. We were very surprised at the time...now..no more!

Last edited by Yaw String; 10th Jun 2009 at 17:11.
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Old 8th Jun 2009, 01:03
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TAT temp increase

Ref TAT temp increase; see in Tech Log:-

http://www.pprune.org/tech-log/37674...ml#post4981558

Note the question about TAT use in the ADC, if true then more than the airspeed indications might be affected – ADC comparator and consequences, use of ADC/TAT in IRS component of ADIRS, ADIRS comparator and consequences, - rudder limiter, cabin alt, etc, etc.
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Old 8th Jun 2009, 01:20
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Faulty pitot tubes

Seems like Air France hve admitted they were faulty.

The finds came as French officials confirmed that the airliner may have lost control after its speed sensors were blocked by ice.
At the time of last Monday's crash, Air France was in the process of replacing what it knew to be ice-prone sensors on the A330 series but had not yet done so on the aircraft which disappeared with
.
Air France searchers recover 16 bodies - Times Online
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Old 8th Jun 2009, 01:47
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A map provided by brazilian Air Force showing presumed last posn and in red the field of debris (=destrocos)

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Old 8th Jun 2009, 03:27
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I think you will find that TAT probe icing will give the illusion of increasing SAT plus some other nasty symptoms.
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Old 8th Jun 2009, 03:39
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I just came across a paper on "Update: finding wreckage under water" from the 2005 International Society Air Safety Investigators conference, available here - some topical background reading.
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Old 8th Jun 2009, 04:44
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Question Achille's heel ?

Airbus' write up about the problem was that the heating in the TAT probes,at times, may be insufficient & lead to the probe icing up followed by the ice rapidly heating up giving false TAT & SAT indications.
I think you will find that TAT probe icing will give the illusion of increasing SAT plus some other nasty symptoms.
ISA and max altitude and coffin corner

Note the question about TAT use in the ADC, if true then more than the airspeed indications might be affected – ADC comparator and consequences, use of ADC/TAT in IRS component of ADIRS, ADIRS comparator and consequences, - rudder limiter, cabin alt, etc, etc.
Reading all this not as a pilot but a certified engineer I'm shocked and astonished, if in today's highly automated airplanes the TAT & IAS probes deliver the most fundamental data to all kind of essential systems, while them self being prone to failures as shown above?

Are TAT & IAS probes the Achille's heels of today's computerized airplanes?

If their data is so essential, should we not have a truly redundant system on board, that also can measure speed relative to the surrounding air but use a different method?
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