AF447

[misd-agin]

http://static.pprune.org/images/statusicon/post_old.gif Yesterday, 12:32 #343 (http://www.pprune.org/4978967-post343.html) (permalink (http://www.pprune.org/rumours-news/376433-af447-18.html#post4978967)) Bearcat (http://www.pprune.org/members/3291-bearcat)

Join Date: Jun 1997
Posts: 598


Overtalks theory is most credible....what I find unreal is the temps to go from -46 to -18c in fell swoop....an incredible phoenomena in the ITCZ. An
A330 at its max alt taking weight into account has 1.3g protection.....make the outside warmer by 30c, well theres only one way your going and that is unfortunetly down re aerodynamics. God rest their poor souls faced with an impossible situation.
http://static.pprune.org/images/statusicon/user_offline.gif http://static.pprune.org/images/buttons/report.gif (http://www.pprune.org/report.php?p=4978967)

ISA is -57C at FL370, so this previous event was already at ISA +9. If the temperature was -19C that would be ISA +38C, which is an amazing temperature at altitude.

I've seen ISA+15 or so until the mid 30's. Above FL350-370 it's been my experience that it's rare to get ISA+15.

[Thermal Rider]

So, right at the point of alternate law, in manual flight, the important bit of kit which stops any strong input to the rudder pedals shearing off the rear flight surfaces failed? Or am I reading into this too much.

Reading the F/ Control FCOM, rudder travel limit is a function of airspeed: above 350ktas deflection is limited to 4deg, below 150ktas to 35deg with a curved slope in between. Aerodynamically, rudder movements that may be needed at low speed would get you into trouble at higher speeds; limits set for higher speeds, may inhibit control inputs too much at lower speeds. True for many control surfaces on the ac. If you lose reliable airspeed input to the flt control system it will remove the limit.

[wes_wall]

.......south bound leg of this A/C. He said they said there was a "black-out" during the leg, but all came right after a while

If such an event occured, no doubt there would have been several ACARS sent.

message from AF 447 regarding the aircraft being in "hard turbulence"

On the other thread I raised this issue also. I cannot recall in all my years of flying that I ever sent an advisory (HF) to our flight following re turbulence. It may have been a write up item, or comment to ATC. Someone replyied that it was an AF inflight proceedure, and normal.

[Dysag]

Re: "I cannot recall in all my years of flying that I ever sent an advisory ..... following re turbulence".

Strange, I agree, unless it was at the start of breakup and he's trying to say why they won't make it. I don't have the timeline to verify that.

[BarbiesBoyfriend]

I find it strange that a message was sent about the turbulence.

Surely, under normal circumstances, one would be doing a whole load of things to try and improve the situation. So why waste time doing something that plainly will NOT improve the situation.

Maybe it was such awful turb that he felt that they might not make it through and that therefore it might be helpful to ensure that some details of the aircrafts plight are known.

Just strikes me as an odd thing to do.

[TripleBravo]

Couldn't a damaged rudder and its impact on the rear bulkhead explain all of the other automated messages?Absolutely not. Air probes are far away and completely independent of cabin pressure. It is as well highly unlikely that any rudder problem would impact the RPB.

NAV ADR DISAGREE message ... doesn't that indicate it is a result of the trouble and not the cause of it?That's a question which cannot be answered for sure at this point in time.

By the way, as far as I remember, the TCAS is fed with positioning data only by ADIRU1. If correct, it just 'needs' one broken input to fail as well.

http://www.weathergraphics.com/tim/af447/af447-radarsim.jpg

http://www.weathergraphics.com/tim/af447/af447-profile.jpg

According to Tim's analysis (http://www.weathergraphics.com/tim/af447/) above they must have been already through the most severe updrafts. Could this mean the turbulences of ITCZ could have turned into sudden warm tailwind at that point? If they controlled the flight with pitch and power as according to SOP re unreliable airspeed, this would explain a lot to me (stall).

Quote:
.......south bound leg of this A/C. He said they said there was a "black-out" during the leg, but all came right after a while
If such an event occured, no doubt there would have been several ACARS sent.Yes, but they would relate to ATA24 (Electrics Power), which was not the case, as already pointed out several times in this thread. The NIL important IFE (in flight entertainment) including ****ty cabin lighting has nothing to do with any important instruments and the safety of the aircraft. Please note there was no known electrical power breakdown on AF447.

[Flyinheavy]

@Barbies BF
Surely, under normal circumstances, one would be doing a whole load of things to try and improve the situation. So why waste time doing something that plainly will NOT improve the situation.

Maybe it was such awful turb that he felt that they might not make it through and that therefore it might be helpful to ensure that some details of the aircrafts plight are known.

Or as it has been said to be off 0200Z could have been a standard AF proc at the entry at Oceanic Airspace, they would have to comment on that. As far as I know, this report has been cited with diferent wording throughout the week and there had not been any official reference as to it's real value....

Everthing dealing with it seems more or less speculative IMHO

[AAA737300BF]

from Post #487:
According to AF press conference:
Take off weight 233T (including) fuel 68 T


from Post #518:
ISA is -57C at FL370, so this previous event was already at ISA +9. If the temperature was -19C that would be ISA +38C, which is an amazing temperature at altitude.

Given the TOW of 233t and an average fuel burn of 7.5t/hr, 3 hrs flight time give a fuel burn of 22.5t, so the weight of the aircraft would have been approx 210,5t after 3 hrs.

Please, could anyone with access to A332 performance manuals have a look at the altitude capability ata) 210t @ ISA
b) 210t @ ISA+10
c) 210t @ ISA+38
and post the results?
Thanks.

[Flyinheavy]

Tim Velasquez:

to the airplane's final reported ACARS position (2014Z,3.578,-30.374) yields a distance of 331.5 nm (381.5 sm) (calculator (http://www.fcc.gov/mb/audio/bickel/distance.html)) in 41 minutes. This introduces consistencies because it yields a ground speed of 485.1 kt (558.3 mph), and at FL350 an airspeed of 288 KIAS/M.841In the first part of the given analysis the positions are declared as extrapolated. In the cited part they appear to be ACARS reported. Where they? Somebody can enlighten me also about the speed calculations, without any irony, may be I just missed something. As stated before I find the analysis a very good peace of work, only needing some explanations.

The reason I post this: as to my calculation the distance btw INTOL and TASIL is 375NM where they estimated at 0223UTC would make 479kt GS

[TripleBravo]

AAA737300BF, that's available, please see one of my previous posts with data from the QRH: http://www.pprune.org/rumours-news/376433-af447-11.html#post4977401 and http://www.pprune.org/4976770-post169.html

http://img189.imageshack.us/img189/9929/qrh409.png (http://img189.imageshack.us/i/qrh409.png/)

[Flyinheavy]

@AAA73700BF:

At ISA+15 the optimum Alt for 210T appears to be FL360 at M.82

according tables

[TyroPicard]

If that hard turbulence message was sent at 0200, that might be in a quiet patch between two storm cells, and it might be to warn CDG engineers that turbulence checks would be necessary after landing. Or it might be Air France SOP.

[CaptJ]

AAA737300BF

7.5T/Hr seems high.
I query as an A300-300 burns around 4,5T/Hr in cruise.

Unless my memory serves me ill.

[hautemude]

Wes Wall

I cannot recall in all my years of flying that I ever sent an advisory (HF) to our flight following re turbulence.

I'm not quite sure what you mean by the above quote re "our flight".

I agree that sending such a message by HF would probably achieve little.

However during my 40+ yrs of flying, I certainly transmitted such information on 2 or 3 occasions on 126.9 or 123.45 or the controlling VHF frequency after what I considered to have been a really good shaking. I can't remember now whether I did so during the shaking but I have a vague memory of doing so on at least one occasion. It's called being professional I think.

While I'm here I think it should be pointed out to the non professionals who contribute, that the ITCZ is always there just like it is always over Africa or elsewhere. It's latitude varies with the season, sometimes it's a pussy, sometimes a tiger. Professional pilots KNOW about it, they are taught route climatology as kids in flying school or I certainly was. If you work long haul for a "proper" airline like AF, I would be astonished if the dangers were not driven home during route training. In my case I have no recollection of ever having to divert more than 40 miles or so off track when flying the South Atlantic. In my experience the storm systems over the USA during the summer could be infinitely more severe.

[pezetaroi]

I'm going for a high altitude stall. Flying at night, through very bad weather, slowing down the airspeed because of the turbulence, and then suddenly ice formation that clogges the pitot-static system and causes amongst other failures an ADR DISAGREE:


NAV ADR DISAGREE (A320)

This Topic is relevant to the following aircraft: 2662, 3123, 3304, 3374


If one ADR is faulty, or has been rejected by the ELAC, and if there is a speed or alpha disagrement between the 2 remaining ADRs, alternate law becomes active, and protections are lost.

-AIR SPD X CHECK


IF SPD DISAGREE :

-ADR CHECK PROC APPLY


Refer to the ADR CHECK PROC paper procedure to determine the faulty ADR.


IF NO SPD DISAGREE:

AOA DISCREPANCY

F/CTL ALTN LAW
(PROT LOST) -MAX SPEED 320 KT


STATUS
-MAX SPEED 320 KT

APPR PROC

-FOR LDG USE FLAP 3


Do not select CONF FULL, so as not to degrade handling qualities.

-GPWS LDG FLAP 3 ON

Displayed, when CONF 3 is selected.

APPR SPD VREF + 10

LDG DIST PROC APPLY

Refer to the QRH part 2, or to the FCOM 3.02.80.

ALTN LAW : PROT LOST

WHEN L/G DN : DIRECT LAW
At landing gear extension, control reverts to direct law in pitch, as well as in roll (see DIRECT LAW procedure 3.02.27).


IF NO SPD DISAGREE:

RISK OF UNDUE STALL WARN

[lolopilot]

...may be because the Captain has delegated duties in the cockpit and while the F/O and himself were dealing with what was at the time a critical, but not yet a distress situation he asked the relief F/O who often seats in the cockpit to send an ACARS message to the company related to the encounter of severe turbulence... He might have had compelling reasons to do it but not enough elements are available at the present time to fully understand his decision. If memory serves, it seems that the chronology of the events shows that this message was sent early on, minutes before the faulty and more critical messages were automatically sent. That is only a scenario among hundreds of possible ones.

[Interflug]

At ISA+15 the optimum Alt for 210T appears to be FL360 at M.82

And at ISA+20 the optimum/max Alt for 210 t appears to be down to FL310 at M.82

And at ISA+38... ? It is not even on the chart...

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?

[river7]

[...some passengers] said there was a "black-out" during the leg, but all came right after a while.Probably just referring to the cabin lighting?

Always impressive for us the SLF, but certainly not "serious"?

[Flyinheavy]

@Interflug

There has been no report about such an ISA deviation at this day. If You read through earlier postings LH507 was 30min before AF same AWY without reporting any abnormalies.

[MG23]

As there are a minor group of dx:ers active on the L-band (microwave band), it could have been possible that additional data could have been recieved and stored on a hard drive at a l-band fan amatuer, as amatuers always are on the edge of possible receiving limits-settings.

The only way I can see to receive the L-band transmissions from the aircraft would be either to have a satellite in orbit close to the one being used for the transmission, or for the antenna to have been way off so it's not pointing towards the satellite at all. Otherwise you'd need a large C-band antenna to pick up the downlink from the satellite; I don't know how many amateurs have that capability and are listening for ACARS data.

Also in mind, these array-antennas has a specific radiaton pattern, and when accessing satellites, usually the NOC keeps an record on time-signalstrength etc for tech-monitoring and billing purposes.

Carrier to noise, error rates and power levels could certainly provide useful information about how accurately the antenna was pointed: I'd presume that information will have been given to the investigators along with the messages.

[TripleBravo]

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:
http://img35.imageshack.us/img35/3999/01020154534300.th.jpg (http://img35.imageshack.us/my.php?image=01020154534300.jpg)

[Will Fraser]

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.

[Gary Brown]

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 (http://tinyurl.com/qbbduy)

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 (http://tinyurl.com/kl7aw2)

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.
]

[Mercenary Pilot]

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.

http://i.dailymail.co.uk/i/pix/2009/06/07/article-1190760-0540AB31000005DC-80_636x363.jpg

[Flyinheavy]

@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?????

[Fly-by-Wife]

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

[Quantz]

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." :hmm:

[mm43]

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

mm43

[Capt Kremin]

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.

[bruppy]

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.
Bruppy

[SergioR]

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

Regards
Sergio

[Milt]

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?

[Fly-by-Wife]

:confused:
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

[Yaw String]

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!

[PEI_3721]

Ref TAT temp increase; see in Tech Log:-

http://www.pprune.org/tech-log/376740-isa-max-altitude-coffin-corner.html#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.

[Gringobr]

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 (http://www.timesonline.co.uk/tol/news/uk/article6450104.ece)

[Flyinheavy]

A map provided by brazilian Air Force showing presumed last posn and in red the field of debris (=destrocos)

http://img.terra.com.br/i/2009/06/07/1226102-3287-atm14.jpg

[amc890]

I think you will find that TAT probe icing will give the illusion of increasing SAT plus some other nasty symptoms.

[OverRun]

I just came across a paper on "Update: finding wreckage under water" from the 2005 International Society Air Safety Investigators conference, available here (http://www.geocities.com/profemery/ISASI.pdf) - some topical background reading.

[Interflug]

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 (http://www.pprune.org/tech-log/376740-isa-max-altitude-coffin-corner.html#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.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?

[BRE]

If I remember correctly from aerodynamics lectures, there is no other reliable way to measure airspeed.

One could use Doppler radar, but that would involve tracer particles. Or one could use a propeller which might give somewhat reliable readings below 300 knots but would completely miss static air pressure.

A GPS derived speed signal might be helpful but lacks information about wind speed and static pressure.

[Captain-Crunch]

Guys my post on page 24 to Airpolice may have a error in it. Several readers have correctly brought into question the 0200? keyboard crew acars report assumption and it's source. I committed the cardinal sin of quoting and believing a journo report with the term "hard turbulence" instead of a real source. :mad: My apologies. The Air France Press Release in English, which is also fishy says:

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.

2nd PR from the bottom (http://www.airfrance.us/cgi-bin/AF/US/en/local/home/home/homepage.jsp;jsessionid=0000NI-3Gsb9QF0mgSyhePGn0PZ:140ufn0s8)

Of course, to re-emphisize: the acars images from French TV are not consistent with what you would expect to see with any electrical problem. All we have at this point is images of that leg report to maintenance via French TV? Right? What we need now is the actual image, or at least some sources of the acars wx report from the crew to [Flight Following] Ops. [The PIREP]

Can anybody provide the source of the last manual transmission? [a credible source, such as an corporate or government spokesperson addmission?]

Thanks

CC

p.s. You guys were right to question that.

[ChristySweet]

Capt Crunch
_____________________


JACDEC SPECIAL ACCIDENT REPORT (http://www.jacdec.de/info/AF447Special/jacdec_special_report_AF447.htm)

Not sure if (or why ) this source is discredited- you asked me to remove prior ACARS message list,
but perhaps pertinent?
If so, further discrediting of rumored radio ( voice? ) transmission ,
" heavy turbulence ."


19:03 - Departure at Rio de Janeiro-GIG - ~22:05 AF 447 is passing Natal and is heading out over the Atlantic at 35.000 feet and with 450 knots - 22:33 last radio contact, AF 447 passing INTOL waypoint - 22:48 AF 447 left controlled airspace of CINDACTA 3, north of Fernando de Noronha Island - ~23:00 AF 447 entered a zone of thunderstorm clounds and turbulences - 23:10 ACARS message indicates that the autopilot was disengaged, fly-by-wire systen reverts to alternate law, data from both pitot static ports lost, TCAS antenna at fault - 23:11 both air data units flight computers (ADIRU) failed, standby attitude indicator (ISIS) lost - 23:12 diagreement of ADIRU data - 23:13 two flight management computers (PRIM1 + SEC1) failed - 23:14 AF 447 sent an automated message indicating an electrical problem and a possible loss of cabin pressure - 23:20 - estimated passing of waypoint TASIL - 02:33 alarm war raised and the search rescue mission began -

[Bleve]

My experience is that some pilots don't fully understand the true significance of a sudden outside air temperature rise (and yes they do occur - I have seen temperature rises of 20-30 degrees).

When we are flying at a constant Flight Level we are in fact flying at a constant 'indicated' altitude. The true height of this Flight Level above mean sea level (AMSL) will vary with the outside air temperature. In cold air it is lower, in warm air it is higher. So when we encounter a sudden increase in outside air temperature, to maintain a constant Flight Level the aircraft has to increase it's true altitude AMSL. ie it has climb against gravity, (but in the flight deck the altimeter and VSI will still show level flight because we are flying a constant Flight Level ie 'indicated' altitude.)

Now to climb against gravity we have to add energy and this ideally comes from the engines increasing thrust. Where the problem arises is if we are cruising near max altitude and the aircraft is cruise thrust limited. If the engines are at max thrust, they can't add any more energy. With the autopilot maintaining a constant Flight Level, but the true altitude increasing, the only available source of energy is speed. ie speed is converted into height and the aircraft's speed reduces. And as has been mentioned before, if you're in 'coffin corner' a stall is not too far away. The only solution is to descend and you may not have much time to make that descision.

[Bleve]

Further to my previous post, a possible scenario might be (and in no way am I suggesting that this did happen):

Aircraft flies through heavy weather and encounters turbulence and icing.
Pitot probes ice up resulting in numerous system failures.
Aircraft flies into a suddenly warmer airmass.
Autopilot maintains constant Flight Level, but with increase in OAT and increased weight due to ice build up, engines are at max thrust and can't maintain airspeed.
Crew are distracted dealing with the system failures and don't notice or have no reliable indication of decreasing airspeed.
Icing on wings results in a higher than normal stall speed.
Ice build up is asymetric so one wing stalls before the other.
Spin ......
:(

[Gumby]

"My experience is that some pilots don't fully understand the true significance of a sudden outside air temperature rise (and yes they do occur - I have seen temperature rises of 20-30 degrees)."

Bleve,

Not to doubt you, but where have you experienced such large changes at the higher flight levels such as FL350? I would also think you are talking in C as only us stubborn Americans think regularly in F (they force me to use C when flying). In my experience at the higher levels, maybe I have seen a change of 3 to 4 degrees C at a constant FL over a lapse of time. Of course, if you are in the middle of a big CB, you are no longer at any one flight level for any period of time. I think I would like to avoid areas prone to 30 degree changes.

To me, 40C isn't hot but 104F is cooking. Oh wait, they are the same. ;)

[Bleve]

where have you experienced such large changes

In the tropics, in and near convective weather, just like the conditions AF447 were in.

[amc890]

Quote:
where have you experienced such large changes
In the tropics, in and near convective weather, just like the conditions AF447 were in.

Are you talking degrees F then?

[Bearcat]

Bleve....you theory is very plausible. Likewise I believe a lot of crews havent a notion of the significence of TAT/SAT temp changes and the impact on flight. this is no way reflects on this accident as we are just guessing what happened.

I also reckon all the acars msg's re prim's/ sec's/adr's where transmitted when the aircraft was out of control.

[IO540]

If I remember correctly from aerodynamics lectures, there is no other reliable way to measure airspeed.

One could use Doppler radar, but that would involve tracer particles. Or one could use a propeller which might give somewhat reliable readings below 300 knots but would completely miss static air pressure.

There most certainly are ways of measuring gas flow velocity; there is a huge industry making sensors which do this. Ultrasonic, coriolis, you name it. The raw data will not be the same as a pitot tube (which doesn't measure TAS anyway) but could be corrected back to read an "IAS" like a pitot tube does.

[Cloud Cuckooland]

Christy Sweet,

Thanks for posting the link to the list of messages. Don't have a maintainence manual but...

FYI - Auto pilot will disconnect at ALTN LAW activation - involuntary disconnect indicated by "AUTO FLIGHT AP OFF" message. ALTN LAW probably activated by multiple ADR disagree / Flags on PFD (same thing).

Also the first (memory) items on the QRH Unreliable Airspeed Checklist if actioned are: Autopilot/Flight Directors and Auto Thrust off.

NAV TCAS FAULT is just a by-product of the ADR problem.

I doubt the ISIS (3-in-1 Standby Instrument) was fully lost: only the Airspeed part as the Attitude is a separate electric gyro powered by the DC Essential or Hot Battery Bus. ISIS Altitude is raw data from the standby static vents (does not go through Air Data Modules) - While pitot icing is likely I feel it is unlikely that the static vents iced up too. So ISIS attitude and ALT should have been reasonable. At the very least ISIS Attitude should have been good

PRIM 1 Fault and SEC 1 Fault - All PRIMs & SECs have ADIRU input but in the case of the SECs it is only Yaw rate - in anycase PRIM 2,3 and SEC 2 were still OK according to the ACARS messages which should have been ample to fly the aircraft. Bit of a mystery there. BTW - I understand QANTAS Flight 72 had slightly different messages i.e. PRIM 1 PITCH FAULT, then PRIM 2 PITCH fault. After that they tripped to ALTN LAW and had no more control problems as it was NORMAL law (improper activation of low speed protection) that was faulty.

If I am reading the messages correctly the Advisory at 0214z (last message) was ATA 31 meaning pressurisation. The pressurisation Advisories applicable are cabin rate > +/- 1800 fpm or Cabin Alt . >8800' - this could be possible without breakup or structural depressurisation as the CPC's (Cabin pressure controllers) may have been getting incorrect data from the ADIRUs.

Whatever happened they certainly had their hands full:sad:

[Captain-Crunch]

ChristySweet,

I'm just having trouble remembering how we knew that there was an ACTUAL acars keyboard message sent, and the exact wording. I'll re-read the whole thread I guess.

Your link to the german web page is NOT a credible source. Do you understand this? You can't keep picking things out of the air. Your previous posting of erroneous information needed to be taken down. Do you understand this?

Questioning any information that we discuss, is NOT discrediting anything. O.K? It is what makes pprune so powerful. I am impressed with the caliber of some of the contributors: such as the acars guys, the techs and many others. Not every one, however, can contribute Christy, because it is outside of your area of expertise. Stick to what you know.

For new people, who just won't bother to read the whole thread (and I know it is long,) or who don't have time, a good summary of what we've been covering is here: (and you should read it!)

Wiki - Air France Flight 447 (http://en.wikipedia.org/wiki/Air_France_Flight_447)

I will update that wiki page when we decide how credible the acars pirep transmission is. Note: wiki is a living document, and is constantly changing. Many items there are being debated right now to be tossed out. The process is impressive.

CC

Alternatively, here are the source images: ACARS Leg Report (http://www.pprune.org/rumours-news/376433-af447-2.html) scroll to the bottom for the big ones.

.

[Yaw String]

Bleve…very good point, and another good reason to consider your optimum FL when requesting cruise level, especially when around CB activity or other potential turbulence situations.
I remember enroute Cun-Mxp, 2000’ above optimum in B767…..random track, with colleague on same routing, 20 mins behind. Enjoying 160kts average tailwind.

On encountering an unforecast 30nm band of mod/severe CAT at 30W, I had already made Pan calls on 121.5 and 128.95 to descend without clearance, ….when,.... my clearance came through on HF.

My colleague was duly warned and requested the same. Lucky to have been off busy OTS.
Downside of random track being no prior warning from traffic ahead…..

[Obie]

Bleve has said, and I quote:

"Now to climb against gravity we have to add energy and this ideally comes from the engines increasing thrust. Where the problem arises is if we are cruising near max altitude and the aircraft is cruise thrust limited. If the engines are at max thrust, they can't add any more energy. With the autopilot maintaining a constant Flight Level, but the true altitude increasing, the only available source of energy is speed. ie speed is converted into height and the aircraft's speed reduces."

Of course, all airline pilots, even brand new First Officers on jet a/c, know that this statement has a major flaw based on lack of knowledge.

Hopefully Bleve will do some research, or at least speak to some of his pilot friends, and withdraw his statement!

[BL]

All this technical discussion is of little value. We will never know. The DFDR records the output of the sensors. Sensors that had failed. I suggest that even if they find the blackbox, it will only add to the mystery.

What we do know is that the aircraft flew into a huge TS and didnt come out in one piece.

How many pilots that fly across the Atlantic would divert 100nm from track to go around a TS like this? -bearing in mind that that same TS will probably make the HF unusable. I have gone 80nm off track to avoid. Scarey with no radio contact, although it was a random track, not a NAT track 60nm from the next one, although TCAS is a nice backup.

If you had carried min fuel and diverting 100nm around weather would mean that you couldnt make your planned destination would you still go around it? Probably less than said yes to the first Q. But we will all be more careful from now on. And carry more fuel if the sig wx chart looks scarey.

[Bleve]

I would also think you are talking in C as only us stubborn Americans think regularly in FYes I am talking °C.

I think I would like to avoid areas prone to 30 degree changes.
You don't get any warning or indications that you are about fly into such areas. They are localised and transient events. With experience you start to get a feel where there is an increased risk of it occuring, but that's about it.

My experience, and it seems it is the same as some of the other posters on this thread, is that the common conditions in which large OAT rises have been seen are:

- tropics
- over water
- nearby or recent convective activity
- flying in stratform cloud (appears as widespread speckled green wx radar returns)

The last time I experienced a large OAT rise was over the Pacific Ocean at about 20°N. We were in widespread upper level Nimbostratus cloud. There were no active cells in the nearby region and we assessed the cloud to be from decayed CBs. The radar return was speckled green. Over the space of about a minute (~10nm) the OAT(SAT) went from about -55°C to about -25°C. Fortunately our aircraft had enough excess thrust available to be able to cope with such conditions and we were able to maintain speed and Flight Level.

[Yaw String]

BL..I am learning much from reading this thread. All real experience threads are valid and the inspired technical discussions should help us all be better aviators.
Nothing wasted here!
Sad & regrettable circumstances........we will all try to learn from their loss!

Pprune at its best!

[Bleve]

Of course, all airline pilots, even brand new First Officers on jet a/c, know that this statement has a major flaw based on lack of knowledge. Hopefully Bleve will do some research, or at least speak to some of his pilot friends, and withdraw his statement!OK Obie, no need to be cryptic, so for my benefit and the others reading this thread, what is the major flaw?

[Bullethead]

Like Bleve and others I've seen temp rises in the order of 20-30 degC passing through the ITCZ between Japan and Australia on many occasions. Usually the first thing I'd notice is that the aircon can't deal with it and you can smell/feel the cabin air become more humid and then notice the SAT rising rapidly. A good reason not to operate right up at or above optimum in that neighbourhood. Once out of the hi-temp area the SAT decreases just as quickly.

Diversions around thunderstorm activity of well over 100nm are not that uncommon in oceanic airspace, I've done plenty over the years.

Regards,
BH.

[Sir Richard]

amc890

I think, as you suggest, TAT probe icing is the reason for apparent sudden transient temperature rise. The probe would be shielded from ambient air for a few seconds until the ice melted.

[Yaw String]

Obie, I am cruising at 2000' above my FMC optimum altitude. Enter cloud and the SAT increases by +20C...By how much would the optimum altitude change in your aircraft?...It happens...unless of course..Sir Richard is correct!

Experts..definitive answer on this one please..real temp rise or indicated due temporary icing effect!

[AirwayBlocker]

Hi Obie

Could I second Bleve's request for a description of the supposed major flaw in his statement?

[amc890]

Quote:
I would also think you are talking in C as only us stubborn Americans think regularly in F
Yes I am talking °C.

Quote:
I think I would like to avoid areas prone to 30 degree changes.
You don't get any warning or indications that you are about fly into such areas. They are localised and transient events. With experience you start to get a feel where there is an increased risk of it occuring, but that's about it.

My experience, and it seems it is the same as some of the other posters on this thread, is that the common conditions in which large OAT rises have been seen are:

- tropics
- over water
- nearby or recent convective activity
- flying in stratform cloud (appears as widespread speckled green wx radar returns)

The last time I experienced a large OAT rise was over the Pacific Ocean at about 20°N. We were in widespread upper level Nimbostratus cloud. There were no active cells in the nearby region and we assessed the cloud to be from decayed CBs. The radar return was speckled green. Over the space of about a minute (~10nm) the OAT(SAT) went from about -55°C to about -25°C. Fortunately our aircraft had enough excess thrust available to be able to cope with such conditions and we were able to maintain speed and Flight Level.

Well I think you just described a TAT probe icing event there.

[FE Hoppy]

could some one tell me how much a 30 °c temperature change will change mach number?

I've spent hours chasing speed in mountain waves with just 5 or so ° temperature changes. I don't remember the formula for calculating Mach from TAT but I'm sure someone on here has it.

[kwachon]

Just a quick refresher of what density altitude is.....

Density altitude is defined as the altitude at which a given air density is found in the standard atmosphere. For a given altitude, density altitude changes with changes in pressure, air temperature, and humidity. An increase in pressure increases air density, so it decreases density altitude. An increase in temperature decreases air density, so it increases density altitude. An increase in humidity decreases air density, so it increases density altitude. Changes in pressure and temperature have the greatest effect on density altitude, and changes in humidity have the least effect.

With that information, you can see the effect of a temperature change on the aircraft altitude. Note also that entering a area of T/storms may well give rise to an increase in humidity thus an increase in density altitude.

KW :ok:

[Interflug]

BT wrote:
But we will all be more careful from now on. And carry more fuel if the sig wx chart looks scarey.In order to carry more fuel they would have needed to drop some weight elsewhere. They were already at 100% max. TO weight... (233 t) (source AF press conference June 5th)

[Bleve]

amc890

If the rapid rise in displayed temperature was due to TAT probe icing then I would expect that there would be no change in engine thrust. If the outside air temp remains constant, then the Flight Level remains constant and there is no requirement for extra thrust. However as explained previously, if the OAT does increase, there is a need for increased thrust.

In the event I described, the thrust did increase - significantly. In fact we reached max cruise thrust and had to select climb thrust to maintain Flight Level and speed. That is consistent with a real increase in OAT, not a false reading due to TAT icing.

[kwachon]

Bleve

Please read my previous post. Look at the temperature change relationship with density altitude, then, look at how the aircraft would be affected if the TAT probe did ice up (a big if) with a change in temperature, then compare that to a natural change in outside air temperature. The time to change will be the enemy as far as the air data computers are concerned. What the ADC then instructs the A/T an A/P to do can be instrumental in how the airframe and engines maintain their integrity.

KW:ok:

[Gumby]

"My experience, and it seems it is the same as some of the other posters on this thread, is that the common conditions in which large OAT rises have been seen are:

- tropics
- over water
- nearby or recent convective activity
- flying in stratform cloud (appears as widespread speckled green wx radar returns)"

Bleve,

Thanks for the information. So you don't think I haven't flown much around the world, I can state I have flown across every line of longitude, as far north as Fairbanks and as far south as Perth. I just have never met the conditions you described after over 30 years of flying (US Navy, TWA, ATA, etc). I will say I have never operated in the South Atlantic area.

One learns something new every day in this business.

I do hope they find the "boxes" so we have a clearer picture and less conjecture.

[Captain-Crunch]

O.K. Here it is. Regarding the Weather transmission from the flight, misreported/mistranslated in the media as "hard turbulence" seems was earlier reported by this French Media outlet:

French Media wx trsmsn (http://www.lemonde.fr/societe/article/2009/06/04/l-airbus-d-air-france-volait-a-une-vitesse-erronee_1202293_3224.html#ens_id=1200707&xtor=RSS-3208)

Using my trusty Google translator here:

Translation via Google (http://translate.google.com/translate_t#fr|en|A%2023%20heures%2C%20soit%20vingt%20minute s%20avant%20l'entrée%20prévue%20de%20l'Airbus%20dans%20l'esp ace%20aérien%20du%20Sénégal%2C%20le%20pilote%20envoie%20un%2 0message%20signalant%20qu'il%20traverse%20une%20zone%20de%20 fortes%20turbulences%2C%20dans%20des%20cumulo-nimbus%20chargés%20d'électricité%20et%20des%20vents%20violen ts.%20Les%20satellites%20météo%20attestent%20)

I get:

At 23 hours, twenty minutes before the entry of the Airbus in the airspace of Senegal, the pilot sends a message that crosses a zone of severe turbulence in cumulonimbus clouds charged with electricity and winds. Weather satellites attest

well, not perfect either...... but what do you expect from a computer?

Here's the source statement:

A 23 heures, soit vingt minutes avant l'entrée prévue de l'Airbus dans l'espace aérien du Sénégal, le pilote envoie un message signalant qu'il traverse une zone de fortes turbulences, dans des cumulo-nimbus chargés d'électricité et des vents violents. Les satellites météo attestent

Anybody Speak French? Wanna confirm that the google translation is right?

Thanks,

So it seems "Severe" is the word we are dealing with here. Ten minutes before the chit hit the fan.

Crunch - Out

[VR-HFX]

Bleve

You're logic and train of thought is on the money me thinks.

And when you are at coffin corner and there is nothing left but to descend but the a/c is telling you something else and you believe it for any number of reasons:ooh:

Disaster beckons.

The other equally important hole on the cheese, is why no diversion?

[Bleve]

Gumby,
So you don't think I haven't flown much around the worldI never thought that for one moment. If I gave that impression I am sorry - it was never my intent.

[kwachon]

Captain-Crunch


It reads after Senegal:

The pilot sent a message indicating he was passing through an area of strong turbulance within Cumulous Nimbus clouds with lightning and violent winds.

KW:ok:

[Gainesy]

qu'il traverse une zone de fortes turbulences,

Fortes= Strong.

[Interflug]

Anybody Speak French? Wanna confirm that the google translation is right?I'm afraid "fortes turbulences" is just blurry terminology like "strong turbulences".


Found this on a French aviation website:



- CAT légère : 75% des cas
- CAT modérée : 15 à 20% des cas
- CAT sévère : 5 à 10% des cas
- CAT violente ou extrême : 1% des cas


http://www.astrosurf.com/luxorion/Documents/symbole-cat.gif

[Grasscarp]

Further to the French message in Captain Crunch's post.

The pilot sends a message signalling that he is crossing....
later on
electricity and violent winds -

Only a few words left out but necessary I think.

[amc890]

amc890

If the rapid rise in displayed temperature was due to TAT probe icing then I would expect that there would be no change in engine thrust. If the outside air temp remains constant, then the Flight Level remains constant and there is no requirement for extra thrust. However as explained previously, if the OAT does increase, there is a need for increased thrust.

In the event I described, the thrust did increase - significantly. In fact we reached max cruise thrust and had to select climb thrust to maintain Flight Level and speed. That is consistent with a real increase in OAT, not a false reading due to TAT icing.

You can get thrust changes. Are you sure the thrust ref didn't reduce toward and beyond the thrust required even to the point that you had to select climb thrust and in fact increase thrust at that point, because everything you describe including selecting climb or even cont thrust is still screaming TAT probe icing to me. I'll see if I can find some reference material from a QRH.

EDIT
Note; not Airbus material
One or more of the following may be evidence of TAT
probe icing:
•The autothrottle disconnects and the
reference/target EPR and reference EPR displays
blank
•The thrust levers are not aligned with the engine
EPR displays
•The engine EPR displays are not aligned with the
thrust levers aligned
•A decrease or increase in the reference/target EPR
displays at a constant altitude and speed
•The engines are unable to achieve the maximum
continuous or the maximum climb rating with thrust
levers fully forward
•The TAT display remains constant and near 0
degrees C during climb, cruise, or descent

[longam]

Hello,
I think a "coffin corner" due to a sudden change in the air temperature is a strong possibility.
My question is not about what did make the flight fall.... is about why the AF crew didn´t avoid that CB (more than 35,000 feets tall), specially when an IB flight behind them requested a change of route to avoid this (and one could supose that the AF crew listened the request)...pilots use to avoid this areas.:confused:

[agusaleale]

Hello,
I think a "coffin corner" due to a sudden change in the air temperature is a strong possibility.
My question is not about what did make the flight fall.... is about why the AF crew didn´t avoid that CB (more than 35,000 feets tall), specially when an IB flight behind them request a change of route to avoid this (and one could supose that the AF crew listened the request)...pilots use to avoid this areas.http://static.pprune.org/images/smilies/confused.gif


I think this is the very first question. The whole thing would be ressumed in two questions:

1) Why did it enter the CB, 2) What happened inside?

For the first question, several things have been argued, most of them banned, such as the problem with the radar on AB.
What I find intringuinly is why this forum is banning pilots who weekly fly the leg SouthAmerica - Europe on AB330/340 and knows very well what they are talkin´ about...

[CDG1]

I just happened to run into this article. Not sure if it was posted yet.

Could this be pure coincidence considering the threats at EZEIZA?

Key Figures In Global Battle Against Illegal Arms Trade Lost In Air France Crash (from Sunday Herald) (http://www.sundayherald.com/international/shinternational/display.var.2512885.0.key_figures_in_global_battle_against_i llegal_arms_trade_lost_in_air_france_crash.php)

Key figures in global battle against illegal arms trade lost in Air France crash
ARGENTINA: Argentine campaigner Pablo Dreyfus and Swiss colleague Ronald Dreyer battled South American arms and drug traffickingFrom Andrew McLeod

AMID THE media frenzy and speculation over the disappearance of Air France's ill-fated Flight 447, the loss of two of the world's most prominent figures in the war on the illegal arms trade and international drug trafficking has been virtually overlooked.

?

[ttcse]

I'm curious, do the most modern jets issue eye-catching alerts to the crew when the temperature changes significantly?

Gumby
Thanks for the information. So you don't think I haven't flown much around the world, I can state I have flown across every line of longitude, as far north as Fairbanks and as far south as Perth. I just have never met the conditions you described after over 30 years of flying (US Navy, TWA, ATA, etc). I will say I have never operated in the South Atlantic area.


In all those years, did you typically operate at upper-altitude limits for weight and available power where this kind of thing would have automatically been a problem? If the oat did make a jump, would've you necessarily noticed?

[Interflug]

We might never know the answer for that.
All we know for fact:

-the plane left with max. certified TO weight
-the CAPT did not ask for additional fuel for deviations enroute. (that is from reports from a pilot who talked to the pilots before TO in Rio, posted somewhere here.) Maybe someone could do the math again, from the published flightplan and see, if the 68 t of fuel included something "for mum" or not.
-they flew close to their planned route right through the soup, while others in the vicinity did bigger deviations around it.

[F14]

Guys, AirFrance is a very professional Airline, equipped with the latest aircraft and flight support. OK they insist on speaking French on the RT, but apart from that I have the highest confidence in the Operation, Training and Engineering.

They have literally 10s of thousands of Atlantic crossings. What we are looking at is a one off catastrophic event. In my mind there are two possibilities:-

1) Bomb

Would be interesting to see what France's Afghanistan deployment is. Air India is almost carbon copy of this accident.

2) Dangerous goods

Like the explosion on the SAA 747 last year, could cargo have caused damage to the airframe? or TWA800 fuel pumps? (4 hours into flight)

[Quantz]

Anybody Speak French? Wanna confirm that the google translation is right?
______________
I'm afraid "fortes turbulences" is just blurry terminology like "strong turbulences".
Found this on a French aviation website:
- CAT légère : 75% des cas
- CAT modérée : 15 à 20% des cas
- CAT sévère : 5 à 10% des cas
- CAT violente ou extrême : 1% des casI'm French and I concur : "fortes" might be translated by "strong" or relating to these CAT categories, by "severe".

Another question here : there is a whole thread on the french Website Eurocockpit about the first ACARS released by BEA apparently lacking any mention of PITOT probe failures. Now the "new" complete ACARS seems to mention these too.
An AF pilot received the transcript of the ACARS from AF maintenance :

"capricorn a écrit:Bonjour à tous
De retour de vol ce matin la maintenance m'a fourni la copie EXACTE (donc complète) des 24 messages ACARS de AF 447;
Sur la premiere ligne , a coté de on avait: ...
CQFD, les 3 pitots étaient HS"

Translation :
"Hi, everybody,
Back from last flight this morning, maintenance gave me the EXACT copy (hence complete) of the 24 ACARS messages from AF447 :
First line, beside F/CTL RUD TRVL LIMIT FAULT, it reads EFCS PROBE 1+2/2+3/1+3.
Meaning all 3 PITOT probe were OOO (out of order)."

[Dysag]

I suggest this topic is a red herring. He was probably carrying 3% of trip fuel as contingency, enough for 150nm.
If that wouldn't have been sufficient, he'd still deviate and worry about the fuel status later.

[golfyankeesierra]

Would the fitting of a rad alt to all commercial aircraft provide a last fall back device should pitot/static input be lost or corrupted
For that you can use GPS altitude. It's also mentioned in the "unreliable airspeed / ADR check" procedure in the QRH:

– GPS ALTITUDE.................................................... .....Display on MCDU

[Carjockey]

AF refered to the a/c hitting 'a zone of stormy weather with strong turbulence' but does not say where this info came from...

Press Releases (http://alphasite.airfrance.com/en/s01/press-releases#communique2537)

Paris, 01 June 2009 - 13:10 local time
Press release N° 2



Versão brasileira abaixo
Air France regrets to confirm the disappearance of flight AF 447 flying from Rio de Janeiro to Paris-Charles de Gaulle, scheduled to arrive at 11:10am local time today, as announced to the press by Air France CEO, Pierre-Henri Gourgeon.

The Airbus A330-200, registration F-GZCP, left Rio on 31 May at 7:03pm local time (12:03am in Paris).

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.

The Brazilian, African, Spanish and French air traffic control centres all tried to make contact with flight AF 447 but to no avail. The French military air traffic control centre tried to detect the aircraft but did not succeed.

216 passengers were on board: 126 men, 82 women, 7 children and one infant.

There were 12 flight crew members: 3 pilots and 9 flight attendants.

The flight captain had a record of 11,000 flight hours and had already flown 1,700 hours on Airbus A330/A340s.

Of the two first officers, one had flown 3,000 flight hours (800 of which on the Airbus A330/A340) and the other 6,600 (2,600 on the Airbus A330/A340).

The aircraft was powered by General Electric CF6-80E engines.

The aircraft had totalled 18,870 flight hours and went into service on 18 April 2005.
Its last maintenance check in the hangar took place on 16 April 2009.

[Captain-Crunch]

I'm afraid "fortes turbulences" is just blurry terminology like "strong turbulences".

Thanks Interflug and pals. So just more imprecise babble for the mindless drones who read newspapers. O.K, that didn't give us much. How about this: There has to be a PIREP in the system somewhere, right? I mean, AF doesn't keep reports like this to themselves do they? Can you guys who are reading this and desperately want to contribute, search the DUATs or AOPA or FAA or Landings.com AV wx links and see if you can find a AF447 PIREP for the Atlantic on the day it happened?

Then we might have the actual turbulence intensity first reported. Maybe.

Good Night All.

CC

To properly attribute, I found this on the first page of the thread from steamchicken:
For the record, the "speed" story in Le Monde says ONLY that Airbus and BEA are going to issue a bulletin today (4th June) that Airbus crew should maintain thrust - conserver la poussée des réacteurs - during difficult weather conditions - en cas de conditions météorologiques difficiles.

That's the first paragraph. Everything else in the story is Brazilian newspapers quoting each other reporting the same bloody ACARS sequence everyone reported days ago. They also say that Alternate Law is an emergency power supply. Further, they say that the various Brazilian papers involved have really good sources in AF.

Well, I'd be stunned if anyone had better sources in AF or indeed in any other big French seminationalised industry than Le Monde, which is after all a Gaullist postwar national project itself, and like most of them does a damn good job.

[Interflug]

The pilot sends a message signalling that he is crossing....

Sorry if I did miss it, everybody is talking about the pilot's message at 2:00 but what substance is behind this?
What kind of message? spoken? written text?
What was the content? How was it transmitted? Who received it?

All I can find is Air France communique Nr. 2
Communiqués de presse (http://alphasite.airfrance.com/s01/communiques-de-presse/#communique2541)
L’appareil a traversé une zone orageuse avec fortes turbulences à 2 heures du matin (heure universelle),

and the rest is "creative journalism" by Le Monde or what?

[Blacksheep]

Things With Wings (http://www.aviationweek.com/aw/blogs/commercial_aviation/ThingsWithWings/index.jsp?plckController=Blog&plckScript=blogScript&plckElementId=blogDest&plckBlogPage=BlogViewPost&plckPostId=Blog%3A7a78f54e-b3dd-4fa6-ae6e-dff2ffd7bdbbPost%3Ac8d85074-e9a2-400a-b350-d511bc8857ba)

Because its in English and so succinct: 2002 CASA AD (http://www.casa.gov.au/wcmswr/_assets/main/airworth/airwd/adfiles/over/a330/a330-001.pdf)

The DGAC AD 2001-354(B) would have been production incorporated on the aircraft concerned, but there remains an inevitable question over the performance of A330 pitot probes in particular, and all other pitot probes used on aircraft in general. Are those "more stringent" requirements of 2002 stringent enough?

[mixture]

For all of those either attempting to show off their french skills or using online translators, you should know that there is a perfectly good english version of the "commniqués de presse" pages on AF.

This would answer many of the pointless postings about what AF meant when they used the word "fortes". :ugh:


See here :
Press Releases (http://alphasite.airfrance.com/en/s01/press-releases/)

Whilst I am in rant mode, can I humbly suggest people please stop padding up this thread quoting unnecessary extracts from the media here .... most extracts are either repetitive or not telling us anything new. Afterall, most of what gets into the media comes from PPRune anyway. :cool:

[Yaw String]

FE Hoppy,

Local MACH 1 = 38.94 x sqrt of SAT in deg absolute.

[Checkboard]

In discussions about large temperature rises near thunderstorms, the process has been researched and documented at the very least in the report from 1992 on VH-JJP in Western Australia:

The aircraft was on a scheduled domestic passenger service flight from Karratha to Perth at Flight Level 310 (31,000 ft). As the aircraft entered cloud while diverting around a large thunderstorm, there was a sudden and significant rise in the outside air temperature. A short time later, all four engines progressively lost power and the aircraft was unable to maintain altitude. During the next 17 minutes, numerous attempts to restore engine power were made without success until, approaching 10,000 ft altitude, normal engine operation was regained.

Appendix 1 of the report contains the Meteorological research of the warm air outflow from the top of the thunderstorm which caused the event.
The report is here:
www.atsb.gov.au/publications/investigation_reports/1992/AAIR/pdf/aair199200286_001.pdf

[Gumby]

"In all those years, did you typically operate at upper-altitude limits for weight and available power where this kind of thing would have automatically been a problem? If the oat did make a jump, would've you necessarily noticed?"

With the Atlantic crossings, we would go to where assigned and then ask for the highest (ride permitting) altitude we could handle based on the "Box" and a bit of common sense. As I said I have seen 3 and 4 degree changes but never 20 to 30. I do tend to glance down at SAT and TAT and, now in Saudi, ISA plus, especially at the first indication of a ripple.

[Milka]

Have a look there guys:

http://www.eurocockpit.com/images/acars447.php

EuroCockpit (http://www.eurocockpit.com/archives/indiv/E009426.php)

Check the ATA 34-11/06
- FLR means FAULT REPORT
- In the sequence, you read 0210 which means 02:10Z
- Then you read 34111506 EFCS2 1, EFCS1, AFS ,,,,P
EFCS is the Electronic Flight Control System. 1 +2 in the present case which causes the Alternate Law 2 to come up
- The most interesting thing is the ",,,,,P" which means "Pitot". They lost all pitots at 02:10Z

Air France and Airbus knew from the beginning that the pitots were the source of the accident. This is the very first message in the time sequence. Air France and Airbus imagined the story of the thunderstorms for the media just to have some extra time to find a plausible cause of crash.

Considering Airbus recent message to operators asking flight crew not to forget Thrust-Attitude concept, it is absolutely scandalous! How do you want to maintain a safe attitude in IMC without PFD/ND and...without ISIS!
Once again, money is everyting and pilots are just considered as monkeys.

For a better understanding, you can also check the incident which occured at ACA (Air Caraibes Atlantique) on the F-OFDF (A330-200) in Sept 08.
http://www.eurocockpit.com/docs/ACA.pdf
The full report is unfornutaley in french but shows the same scenario: Atlantic crossing, severe icing, etc. The flight crew had to cope with a very difficult situation including a massive unreliable airspeed caused by pitot malfunction. After a meeting with Airbus engineers, Air Caraibes Atlantique took the safe decision to modify Thales pitots ref PN C16195AA by ref PN C16195BA (read pages 12 and 13).
Air France could have taken the same appropriate actions after many critical incidents which occured in less than 3 years (6 ASRs confirmed by Air France on the 6/11/08)

PS: Is there any Airbus driver who could translate the full report (from french to english) which is synonymous of dynamite for Airbus and Air France?

PPS: Check also
200806143 (http://www.atsb.gov.au/publications/investigation_reports/2008/AAIR/aair200806143.aspx)

http://www.atsb.gov.au/publications/investigation_reports/2008/AAIR/pdf/AO2008070_interim.pdf

[widmimabi]

We always check the radar on the taxiways before departure, especially in Sao Paulo and also to overcome the problem you wrote with the intensity knob.
For the advisory about cab press., I assume that's because in case of triple ADR fault, you lost CPC1+2, so you have to manually control the pressurisation, then it could a advisory about cab pressure rate because it's very difficult to adjust it when you decide to descent for example.
So for me there is no sign of rapid decompression.
In my last recurrent training, we had a double ADR fault and the flight instructor gave a third ADR fault just for fun, eventually we manage to land but it,s very tricky. The instructor told us after that we were in the group of survivors ( around 30 %), and we were not at FL350 and not in the middle of the ocean and CBs.
What i don't understand is why the PRIM1 and SEC1 disconnected, probably because of strong turbulence.

[Rananim]

I doubt the ISIS (3-in-1 Standby Instrument) was fully lost: only the Airspeed part as the Attitude is a separate electric gyro powered by the DC Essential or Hot Battery Bus. ISIS Altitude is raw data from the standby static vents (does not go through Air Data Modules) - While pitot icing is likely I feel it is unlikely that the static vents iced up too. So ISIS attitude and ALT should have been reasonable. At the very least ISIS Attitude should have been good


29 pages before some decent information on Airbus' standby instrument.Putting bomb/fire theories aside,they either:
a)encountered weather phenomenon that was beyond recovery
b)encountered recoverable weather phenomenon but didnt have the tools(attitude reference) to get out of it
c)encountered recoverable weather phenomenon,had attitude/N1 and GPS alt/GS to fly the unreliable airspeed procedure in theory,but failed to achieve it.Is the procedure feasible at max cruise alt?Its drawn up for climb phase(below/above FL 100) with 5 deg as initial target.Unreliable airspeed at max cruise alt,and you descend to improve margins!

Not enough discussion/focus(IMHO) on:
-ISIS;what did they have in the way of basic instrumentation.Can the ACARS messages give a defintive answer on this?
-both PFD's disabled?ACARS messages prove this?In the Adamair crash,the Captain killed everyone simply because he didnt hand over control to his First Officer who had reliable flight instrumentation.
-mechanical gyro versus laser gyro-
-standby instrumentation philosophy;independent,self-contained,standby inverter powered,integral lighting,"old-school" technology(simple mechanical gyro,no interface with ADM)..not one mechanical gyro installed on these high-tech aircraft including B777..does it break the KISS principle?Why not have a third mechanical gyro on center panel for triple redundancy?
-wx radar interpretation..training is woefully inadequate
-this obsession with modern pilots for climbing as high as they can, above opt alt,like its a game or badge of honor..I see it all the time.They set max alt-300/400' into the step clb box and say "We can get above this and save some fuel as well".In turbulence,you generally descend,unless you're already below opt alt(light) and/or PIREPS indicate climb is favorable.
-Interflug's discussion on weight has all but been ignored/dismissed..take off was at max weight..payload calculated on standard weights,not actual..assume overweight condition and treat FMC-generated opt alt with a degree of suspicion..mentally adjust by -1000 and take another 2000'(or more) off when turbulence is en-route.
-Diversion strategies..ie divert early on,dont climb above,once you take a decision dont back down,theres no shame in a fuel stop after diversion.

[DC-ATE]

Dysag -
I suggest this topic is a red herring. He was probably carrying 3% of trip fuel as contingency, enough for 150nm.

We don't know that yet.

If that wouldn't have been enough, he'd still deviate and worry about the fuel status later.

I'm sorry, but there are "management-type" pilots, along with others, who would NOT. Not all pilots are as conservative as you (?) and I are/were.

[Yaw String]

Ok,
Reading the Australian BAE 146incident analysis of met conditions contributing to the cause of the engine rollbacks we have the Fohne effect at altitude. The same effect that caused a 15 deg temp rise in my garden in Bergamo, south of the Alps one December afternoon, within less than 30 mins.
The dynamic effect of the tropopause causing air to rapidly descend, with a modified moisture content, and now drier that the surrounding air mass and rapidly heating as it goes until it runs out of energy.
And I always thought hot air rises! God knows how I got my Siver C!

[Mint79]

F14, totally agree with your theories :D. If it was a coffin corner or pitot icing issue or any of the other failures speculated on here then why did the crew not communicate with a nearby aircraft on HF at the very least??

The Air India is as F14 says, a carbon copy: the squawk disapeared from radar, as did the AF447, no 7700 was picked up and ZERO mayday calls were made..


Guys, AirFrance is a very professional Airline, equipped with the latest aircraft and flight support. OK they insist on speaking French on the RT, but apart from that I have the highest confidence in the Operation, Training and Engineering.

They have literally 10s of thousands of Atlantic crossings. What we are looking at is a one off catastrophic event. In my mind there are two possibilities:-

1) Bomb

Would be interesting to see what France's Afghanistan deployment is. Air India is almost carbon copy of this accident.

2) Dangerous goods

Like the explosion on the SAA 747 last year, could cargo have caused damage to the airframe? or TWA800 fuel pumps? (4 hours into flight)

[The Green Goblin]

As I said back in the original thread, icing in my experience is the most dangerous result of flying in bad wx. Ironic if it turns out the pitot system iced up.

RIP :(

[shandar]

Sooo. My first post here! This is based on some somewhat crude calculations but should at least give us newbies an idea of 1. what the coffin corner is and 2. what happens if there is a sudden temperature increase.

Note that this graph is NOT made for a specific aircraft, the calculations are based on dummy figures for illustrative purposes. Also, the graph is not valid below FL250 (this is based on a/c being in cruise configuration). There are two flight envelopes in this picture, one at ISA (solid) and one at ISA+30 (dashed). MDD is the drag divergence Mach.

http://img192.imageshack.us/img192/6957/coffin.jpg

So, if you are at 37 000 ft and have a sudden temperature increase you can find yourself dangerously close to a low speed stall, however adjusting your speed will means you get Mach effects and flutter as soon as you leave the high temp area. You are essentially in a coffin corner situation even though the individual flight envelopes gives you a decent speed margin.

[Andy_S]

The Air India is as F14 says, a carbon copy: the squawk disapeared from radar, as did the AF447

No, the AF447 'squawk' did not "disappear" from radar; AF447 was well outside radar range when it transmitted it's final messages.

Am I the only person to think that the BS content of this thread is beginning to creep up again?

[Quantz]

Milka, exactly what I mentioned here :
#599.
See original ACARS link here.
Eurocockpit - Accueil (http://www.eurocockpit.com/index.php)http://www.eurocockpit.com/index.php

""
A 0210, le premier des deux "FAULT REPORTS" concerne donc l'ATA 34 (message "FLR [...] 34111506EFCS2 [...]") et signifie :
ATA 34 (navigation)
11 (Sensors, power supply and switching)
15 (Pitot probes)
06 (cruise)Le sous-ATA 11/15 concerne donc... les tubes Pitot. Avec comme conséquence la panne FLR 27933406 (Flight control primary computer en croisière), puis toute la longue liste des messages WRN (WARNING) qui découlent de la perte totale de références anémométriques."
(...)
"En clair, quelques minutes après l'accident, le BEA, Airbus et Air France avaient bien entendu le contenu des messages, et leur signification. Ils savaient qu'il s'agissait - de nouveau - d'un problème sur les tubes Pitot."

Translation :
"One of the first two fault reports is relative to ATA34, meaning "PITOT sensors". Hence the consequence, FLR 27933406 failure plus the whole series of WRN messages, etc."
(...)
"Clearly, AF and BEA knew right after the accident the content of these messages and understood they had — again — a PITOT problem."

EuroCockpit (http://www.eurocockpit.com/archives/indiv/E009426.php)

One of the 3 pilot unions refuses any A330/A 340 flight if 2 over 3 PITOT are not replaced NOW.

See this DGAC (french FAA) directive dating back 2001 about "severe incidents related to PITOT".

Image 2001 354.JPG (http://www.imagup.com/imgs/1244462433.html)


PS : Sorry, guys, but I don't have the ability to post the PDF,
I apparently don't have access to that functionality here.:sad:

[Quantz]

Dysag :

Read that internal note from one of the 3 french pilot unions :

"REFUSEZ TOUT VOL SUR A330 / A340
N’AYANT PAS AU MOINS
DEUX SONDES PITOT MODIFIÉES"

Translation : "Refuse any flight on A330/A340 unless they have at least two sensors over three replaced."

They relate also a prior incident with ACA flight occurring last september, exactly similar to AF447 problems.

EuroCockpit (http://www.eurocockpit.com/archives/indiv/E009426.php)

[INTEL101]

This just reported on Bloomberg:

June 8 (Bloomberg) -- US Airways Group Inc., the smallest U.S. full-fare carrier, and Aer Lingus Group Plc are replacing air-speed sensors on Airbus SAS A330s similar to equipment on an Air France jet that crashed off the coast of Brazil.

Not sure where the SAS comes from.

[HundredPercentPlease]

FE Hoppy,

This page will provide the speed/temperature calculations you need:

Aerospaceweb.org | Atmospheric Properties Calculator (http://www.aerospaceweb.org/design/scripts/atmosphere/)

[Dysag]

SAS signifies the type of company. Like INC in the US or PLC in the UK.

[RatherBeFlying]

Le Monde ArticleUn journal de Sao Paulo, le Jornal da Tarde, a eu connaissance de la chronologie et de la teneur de ces messages, selon lui grâce à une source proche de la compagnie française. Ces informations ont été publiées, mercredi 3 juin, par le très sérieux Estado de Sao Paulo (les deux quotidiens appartiennent au même groupe de presse).Two respected Sao Paulo papers (owned by the same press group) the Jornal da Tarde and Estado de Sao Paulo published the messages June 3. Perhaps a Portuguese speaking member can check out those articles for more details.

AF Press Release: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.The language leads me to suspect that somebody in AF checked the satellite images and provided this information to the person(s) writing the PR. Note that the next sentence goes on to discuss ACARS reports. Now all it would take for a rumoured report of pilot or ACARS reported turbulence to be produced from this PR is a bit of journalistic legerdemain:=

[wes_wall]

From the AF Press Reports site, the only reference to strong turbulence was their second press release, and this seems to be a generic statement.

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.



They make no reference to how this information (turbulence) was obtained, but I note On the other hand that they are very specific when it comes to the ACARS. Seems like one is documented, and the other ??? Did the BEA briefing on Saturday reveal any info on the validation of turbulence area?

[TyroPicard]

shandar
Nice try with the graph - but the max altitude (peak of the graph) should be several thousand feet lower as well.

[bia botal]

The Air India is as F14 says, a carbon copy: the squawk disapeared from radar, as did the AF447, no 7700 was picked up and ZERO mayday calls were made..

If the crew where battling severe turbulence at the time i would say that Sq 7700 was the last thing on there minds.

Ironic if it turns out the pitot system iced up.

Or completely removed from the airframe.

It is more than blausable that the crew where doing everything right regards working there way through a line of CB's only to fly under a anvil, and i am sure most of us have seen the results of what heavy hail can do to a airframe. and it would more than account for the signals sent to AF, as well as leaving little time for the crew to react as systems failed before the aircraft become unflyable.

[SaturnV]

Yaw String, from a meteorologist in the United States commenting on Appendix 1 in the Australian investigation:

"What's stated in Appendix 1 also happens in the CONUS. A nighttime MCS can produce considerable downward motion on the flanks of the MCS (what flank depends on the environmental winds). This creates a warm pocket of air due to the rapid subsidence from the stratosphere and sometimes can be seen on infrared as a "warmer" area of cloud tops immediately to the north or west of tstms, embedded in colder cloud tops. The MCS also reeks havoc on flight level winds and can increase them by 50kts or more on the north side of the complex,when compared to modeled flight level winds. I see this all the time in the spring."

MCS is Mesoscale Convective System
He was speaking for the Northern Hemisphere; it may be in the Southern Hemisphere, the winds might appear on the south side of a MCS, but I don't know that.

[Graybeard]

All I've read implies the airspeed goes to zero when the pitot tube ices over. Do these Thales pitot have a small drain hole that allows the impact air to bleed off to zero? Otherwise, the airspeed indicator should show the speed at which total freezing occured.

Does the system complexity of the A-3xx cause pitot icing to have more gravity than in a simpler airliner?

[XPMorten]

On the topic of sudden temp rise, europe IR today;

http://www.meteoliguria.it/MSG6H/EURO_108.jpg

[west_yorkshireguy]

Hello everyone. Please don't bash me if this has already been posted by someone else.

I have just come accoss this picture of the tail section of the aircraft which has just been found. Obviously not the entire tail section but a great deal of it.

Does this show anything interesting from the experts on here?

http://www.fab.mil.br/portal/voo447/FOTOS/080609/foto_3.jpg

http://www.fab.mil.br/portal/voo447/FOTOS/080609/foto_1.JPG

[weatherdude]

Hi

This is a normal satellite picture and you can't see any sudden temperature changes on those. You see the temperature of the closest cloud, water or ground surface which can be seen by the satellite. Warmest over subtropical waters or hot land in the afternoon, coldest on cloud tops. But these varying temperatures vary with altitude, so what you don't see is a horizontal change in temperature. And BTW, the stories in this forum about temperature changes of 20-30 degrees (what degrees?) horizontally and at short notice are not realistic. We are talking about a few degrees centigrade with a difference in cloud or out of cloud.

The temperature differences met vertically in SEV TURB may be much bigger than those horizontally, just by the up and down of the aircraft. In a cloud, the the horizontal temperature is quite uniform.

[rer47]

In post 552, Flyinheavy posted a recent FAB Google Earth map of the debris area. Unfortunately this is not really a map, but a sketch of the area. The distances shown (79km, 318km, and 824km) cannot even be plotted since they don't meet at a single point. The reporting point TASIL is mislocated about 150 km NE of its actual location.

The 79 km and 318 km distances more or less plot at the location of a previously reported position where the first bodies evidently were recovered (3° 34.08'N, 30° 27.30'W - from the 6-6-09 FAB PowerPoint).

Yesterday FAB posted some photos of the search, among which is a shot of one of the maps used in the search. It is interesting to see a map used by the SAR teams - this shows that water droplets have smeared the ink, and evidently has signatures of the team members:

http://www.fab.mil.br/portal/voo447/FOTOS/dia0606/carta_da_operacao_assinada.jpg

I have warped the northern portion so it is flat and referenced to latitude/longitude. On this I have plotted in white the aviation waypoints and the location of St. Peter and Paul Rocks. The actual location of TASIL matches that point on the SAR map fairly closely, but other points do not. In yellow I have plotted the 0214Z ACARS location (N3.5777 W30.3744) and the 6 June Recovery location where two bodies evidently were found (3° 34.08'N, 30° 27.30'W). Also plotted in yellow is the "AF447 ultima reporte" location taken from the 6 June FAB PowerPoint presentation.

Interestingly, the SAR map shows yet another location for the last position of AF447 - the red airplane symbol about 27 km WSW of the "AF447 ultima reporte" point. The remainder of the text on the SAR map is difficult to read, but most of the red marks are labeled "Debris." Possibly the red marks inside the northern shaded box are radar targets reported by the R-99 aircraft. The ACARS 0214Z and Recovery locations lie inside a reported Debris area.

-rer47

http://www.eskimo.com/~reanier/FAB_06-06-09_SAR_map.jpg

[Christodoulidesd]

The tail section photo brings odd resemblances with this one:

ASN Aircraft accident Airbus A300B4-605R N14053 Belle Harbor, NY (http://aviation-safety.net/database/record.php?id=20011112-0)

[Broomstick Flier]

Thanks for posting the links yorkshireguy, for those having problems accessing the image from the FAB link, I uploaded one of them to imagesack:
http://img145.imageshack.us/img145/4026/af447verticalstabiliser.jpg

Looks like a fairly intact (save from some damage on the rudder's base) vertical stabiliser.

[wes_wall]

First glance looks to me like a carbon copy of AA. Not implying the same cause, just that the tail section appears to have failed at the same place.

[rp122]

I note that CNN are reporting seabed depths in the search location as being between 6000m and 8000m.

A quick lookup indicates that modern nuclear submarines have a maximum operating depth (in peacetime) of less than 500m.

[west_yorkshireguy]

No problem. I am no expert, but wanted to share the pictures as not seen them anywhere else and may give a clue of some sort. It does look like a very similar picture to the A.A crash in 2001 when the rudder was found.

Here is the other picture in case people have trouble with the links:-

http://img208.imageshack.us/img208/8950/foto1s.jpg

[cringe]

From Le Figaro (04/06/09) (http://www.lefigaro.fr/actualite-france/2009/06/04/01016-20090604ARTFIG00070-af-447la-piste-d-une-desintegration-en-vol-.php):

Refusant à ce stade d'interpréter la cascade de messages d'alerte Acars transmis par l'appareil peu avant le crash, M. Arslanian a simplement précisé mercredi que le pilote du vol AF 447 a évoqué «de fortes turbulences» lors de son ultime contact avec les contrôleurs du ciel brésiliens.

Refusing at this stage to interpret the stream of ACARS message alerts transmitted by the aircraft shortly before the crash, Mr. Arslanian (head of BEA) simply specified Wednesday that the pilot of flight AF 447 evoked “strong turbulence” at the time of his last contact with the Brazilian ATC.

[MartinS]

Yes, subs usually hover around 100m below the surface. However, more importantly, subs have listening capabilities that can detect a whisper at 8000m, which is why one was sent to the crash site.

[Quantz]

According to a french website, some passengers may have had donned their oxygen masks.

A silent tought here for these people. :sad:

[Flyguy2006]

Been reading all your posts with interest but have one question.Now the tail section has been recovered, where exactly are the FDR & CVR's located in the tail section?

[DCrefugee]

Only the vertical stabilizer has been recovered, according to the posted images, and was separated from the aft fuselage, where the recorders are mounted.

I'd guess the aft fuselage is on the bottom, with the recorders. Question is when the two became separated...

[Fzz]

I am no expert, but wanted to share the pictures as not seen them anywhere else and may give a clue of some sort. It does look like a very similar picture to the A.A crash in 2001 when the rudder was found.What will matter is where the vertical stabilizer was found. If it is close to other wreckage, I would think it is likely it was still attached for most of the descent. Can't read too much into this without more information.

[mhod]

Does anybody know if a large object travelling at high speed impacting water would be detectable to the seismologists who monitor earth tremors and 'quakes?

[cwatters]

How fast would the pitot have to freeze for all three failures to be reported in just one message? If they had failed at say 5 min intervals there would be three seperate messages as each failed? How far apart would they have to fail to be sent as seperate messages or doesn't it work like that?

[Aerochti]

http://img338.imageshack.us/img338/6310/dfdrcvryz0.jpg

[geneman]

Looks like it fractured about where I've drawn the green line. Rudder is still attached.
http://farm4.static.flickr.com/3408/3607946092_3036953aa3.jpg?v=0
http://farm3.static.flickr.com/2466/3607095887_f58bc1210c.jpg?v=0

[cwatters]

Does anybody know if a large object travelling at high speed impacting water would be detectable to the seismologists who monitor earth tremors and 'quakes?

I doubt it but when the WTC collapsed the shock was detected about 300 miles away. Some info on that here..

Seismic Detection (http://www.geology110.com/seismic.html)

The aircraft impacts registered local magnitude (ML) 0.9 and 0.7, indicating minimal earth shaking as a result. The subsequent collapse of the towers, on the contrary, registered magnitudes of 2.1 and 2.3

[Mercenary Pilot]

Looks like it fractured about where I've drawn the green line.

I disagree, I think the photograph you have used/photo-shopped is at an odd angle.

To me, the vertical stabiliser has broken off at the lugs and is almost complete.

[rer47]

lios727 asks about debris locations.

See my posts at:

Crash location (http://www.weathergraphics.com/tim/af447/forum/index.php?topic=3.0)

For an analysis of the FAB maps, including one used by the SAR teams.

-rer47

[Dysag]

"Seismographic recorders in Halifax and in Moncton, New Brunswick, recorded a seismic event at 0131:18, which coincides with the time the aircraft struck the water".

[Not_a_pilot]

Further to Mercenary Pilot re: vertical stabilizer break.

You can see the white below the bottom of the stripes in the recovered vertical stabilizer, suggesting that it's the whole thing. That photo of the stabilizer in the water was taken from an angle that changes the perspective of the stripes, I believe.

[Config Full]

The Air France Technical crew union ALTER is calling AF crews to refuse to fly the fleet of A330/A340 that do not have at least two modified pitot probes.
source in french: ALTER - Accueil (http://pagesperso-orange.fr/syndicatalter/)

[Clandestino]

My experience is that some pilots don't fully understand the true significance of a sudden outside air temperature rise

You are not even avare of how thrutfully you have spoken.

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.

Using my faithful Felsenthal MB-2A (it gives very good results for troposphere which start diverging above tropopause but not by much), I estimate that your density altitude would jump from appx 37600 to 40100 ft, provided there were actual temperature rise.

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.

And that makes density alt jump from 38900 to 42300 ft. Now ask yourself whether your wings would support at your new density altitude and whether your engines would give you enough trust to serenely cruise along. Tim Vasquez knows enough to state with confidence that thermal bubbles with 20-30 K higher temp than surroundings are thermodynamically severely improbable or, in layman's terms, impossible.

Congratulations fellows, you have witnessed very rare phenomenon. What you've seen was false excessive TAT reading, probably caused by TAT probe blockage, probably caused by ice cristals in cirruses. All we currently have about it is anectodal evidence that suggests that it happens very, very seldom. Being shy an rare beast we know very little about its habits and habitat apart that it occurs in temperatures below -40°C where it's assumed that ice is too dry to stick to anything. We can only guess that under certain circumstances it can thrive on pitot probes too.


Regarding the AF447: we don't know yet if it actually entered the CB or not so asking why did it enter the CB is pointless. Our only hope of finding out what exactly happened is recovering the CVR and FDR in good shape. And very, very, very thin hope it is. Oh, and IR needs TAS input to keep itself upright.

Photos show the composite tailfin with rudder still attached. Obviously it floats so currents have moved away it from the original splashdown point. Also apparent lack of damage on the side and leading edge has some implications but I don't intend to be the first one to write it down on the PPRuNe.

[Dustoffuk51]

Err, excuse my ignorance but if were looking at an unreliable airspeed caused by pitot malfunction, can we not measure airspeed by GPS???

[Fly-by-Wife]

Here is an update from Tim Vasquez on the topic of "sudden upper tropospheric warming" (quoted in full with his permission):

Update / June 8, 2009:

It was brought to my attention (thanks Bill S.) that an episode of sudden upper tropospheric warming has been quantified in the peer-reviewed literature (see here, PDF). Though I had ruled out sudden warming in earlier updates, I had only been considering buoyant cumulonimbus ascent, in which case a 30-degree rise in the cloud would be unprecedented and indeed unsupportable by the theta-e profiles in the air mass feeding the storm, though if it did occur the vertical velocities and turbulence potential would be astronomical.

Though stratospheric "warm sinks" and "cold domes" have been a part of forecasting for years, this paper proposes a very intense, small-scale, convectively driven downdraft mechanism caused by the penetration of a mesoscale convective system into the stratosphere. The paper identifies a scale of about 75 km in width and an anomaly of 18 Celsius degrees. Any forced downward motion from the stratosphere like this will cause very strong adiabatic warming and associated drying, characterized by a profound lack of high cloud layers and low radiance on water vapor imagery (which by a stroke of luck is most sensitive to the upper troposphere). Since a mesoscale signature like this is well within the sampling capability of the GOES and METEOSAT platforms, I immediately reviewed the water vapor loop (SSEC). However it does not appear to show any anomalous subsident signatures. The area to the north of the MCS appears to show normal synoptic-scale subsidence within the trade wind inversion and the A330 is not believed to have made it this far north anyway.

I do have grave doubts a warm, mesoscale subsident area would be enough to significantly disrupt the A330 flight, and occurring in clear air there is a good chance any failure would be recoverable. I will however continue pondering this idea, will work this topic into the study, and will be glad to entertain other thoughts in this direction. The mystery continues.

-- Tim Vasquez
Weather Graphics / Norman, Oklahoma

from Air France 447 - AFR447 - A detailed meteorological analysis - Satellite and weather data (http://www.weathergraphics.com/tim/af447/)

FBW

[Bealzebub]

Err, excuse my ignorance but if were looking at an unreliable airspeed caused by pitot malfunction, can we not measure airspeed by GPS???

No. Airspeed is the speed at which you are moving relative to the surrounding air (which is probably also moving itself.) GPS measures the speed you are moving relative to the Earths surface (ground speed,) or more properly the speed you are moving relative to a selection of satellites in orbit.

[PlatinumFlyer]

Clearly this is the case as one can see the solid white line at the bottom of the fin located just above where it is attached to the fuselage. This and the lug image looks frightenly like AA587. The question is when the fin departed in this case.

[jehrler]

I assume that one of the reasons (other than listening capabilities) that France has dispatched a sub is to use radar/sonar to map the floor to look for large pieces of wreckage.

There is some hope that the aft section of the fuselage may remain in fairly large chunks so, rather than just searching for the FDR & CDRs, they are looking for the much larger pieces of the aft fuselage.

I would hope the US Navy would be aiding with their undersea maps of this area to help the search for anomalies.

[vapilot2004]

I doubt the ISIS (3-in-1 Standby Instrument) was fully lost: only the Airspeed part as the Attitude is a separate electric gyro powered by the DC Essential or Hot Battery Bus. ISIS Altitude is raw data from the standby static vents (does not go through Air Data Modules) - While pitot icing is likely I feel it is unlikely that the static vents iced up too. So ISIS attitude and ALT should have been reasonable. At the very least ISIS Attitude should have been good

These are also my thoughts.

At the very least altitude & attitude should have been available to our crew. Power & pitch would be the NNOP per the unreliable airspeed drill.

Has anyone ever ran this in the sim at altitude? I have set up for lower altitudes. It was no picnic. I can't imagine the challenges the real life situation would entail above FL300.

[VinRouge]

Does the A330 have an emergency Yaw Damper for use at altitude, or doesnt the 330 have dutch roll issues at height?

How does the aircraft respond in alternate law and is there any requirement for an emergency descent to assist the yeaw damper in Alternate law?

[DCrefugee]

Images from the NTSB's investigation into AAL587's crash are here:

NTSB - American Airlines Flight 587 (http://www.ntsb.gov/events/2001/aa587/tailcomp.htm)

[con-pilot]

Has anyone ever ran this in the sim at altitude? I have set up for lower altitudes. It was no picnic. I can't imagine the challenges the real life situation would entail above FL300.

I'll only make this comment. Years ago I was flying a Jet Commander at FL41.0 weaving around the tops of a line of thunderstorms using radar and visual clues. We were passing between the tops of two cells and were hit by lighting which caused both the DC and AC generators to trip of line along with the battery buss.

All I had left was the standby attitude indicator and the co-pilot's airspeed indicator and altimeter. Shortly after this electrical failure we entered IMC and encountered light to moderate turbulence. It was very difficult to fly the aircraft, it seemed as if it was a hour before we came out the other side of the line, but in reality it was only about fifteen minutes.

In summation, it is not easy flying on standby instruments at high Flight Levels, no matter the size of the aircraft.

I just hope they find the boxes.

[Afasa]

About the temperature, this reminded me a troubled NOAA Hurricane Hunter flight to Hurricane Felix in September 2007 who measured temperatures at 10,000 feet 25º C warmer than normal for that altitude. I suppose there are some similarities between hurricane convective hottowers (http://www.google.com/search?hl=en&q=hot+towers&btnG=Google+Search&aq=f&oq=hot+towers&aqi=g10&=Google+Search&=I%27m+Feeling+Lucky&emsg=NCSR&ei=5UYtSuvfNdCNsAaUpuH6CQ) (tropical cumulonimbus) with a strong convective complex in ITCZ.


The pressure at the bottom of the eye had hit 934 mb, and the temperature outside, a balmy 77 degrees at 10,000 feet. This is about 24 degrees warmer than the atmosphere normally is at that altitude, and a phenomenally warm eye for a hurricane. N42RF then punched into the northwest eyewall. Flight level winds hit 175 mph, and small hail lashed the airplane as lighting continued to flash. Then, the crew hit what Hurricane Hunters fear most--a powerful updraft followed a few seconds later by an equally powerful downdraft. The resulting extreme turbulence and wind shear likely made the aircraft impossible to control. Four G's of acceleration battered the airplane, pushing the aircraft close to its design limit of 6 G's. Although no one was injured and no obvious damage to the airplane occurred, the aircraft commander wisely aborted the mission and N42RF returned safely to St. Croix.

Wunder Blog : Weather Underground (http://www.wunderground.com/blog/JeffMasters/comment.html?entrynum=776&tstamp=200709)

[tubby linton]

Seeing the photograph of the fin being recovered made me look again at one of the failure messages sent by the ACARS:
272302006 F/CTL RUD TRV LIM FAULT
IF the failure was corrupting speed data and the rudder travels had gone into low speed(full deflection) mode it would have been very easy to rip the fin off the aircraft.

[Dani]

The vertical stabilizer looks very similar to that of the A300 from AA587. This is not especially surprising because these stabilizer are built to break there. The composite structur is attached with several bolts just on top of the rear fuselage. You also will be not surprised when the engines will be found broken off the wings somewhere at the pilon.

Dani

[gbour]

and there is of course this:

https://www.pprune.org/rumours-news/166083-air-transat-loses-a310-rudder-inflight.html

[Flyinheavy]

@DC ATE:

You are with doubts that the flight had the required uplift of fuel including 3% Route Reserve. I would call this at least a big speculation, now I do not know what the ETOPS requirements of AF are (reserves may vary from operator to operator depending on certification of the authority envolved). But I am damn sure, that they had all legal requirements fulfilled.

Concerning Abnormal Airspeed Indication Procedure, I am Boeing driver, do not know much about Busses, but one thing catches my attention:
I cannot imagine that the high altitude cruising attitude of a bus is much different to other types. Makes my think that max 3,5° would be the value to start with and about 95% N1. Felt kinda uneasy people posting here that You go to 5° Pitch. You are at max altitude remember.

Reading a lot posts claiming problems at high altitude, I always tended and will go on so, to ignore too high levels in CFPs (company flight plans), never encountered any stability problem and at the end of my flights the fuel bill was not higher as if beeing flying the sometimes unrealistic high levels.

[TripleBravo]

these stabilizer are built to break there.Some big BS here. There is no intended break line whatsoever.



As pointed out in a more in-depth article here http://www.pprune.org/tech-log/376345-air-france-a330-accident-3.html#post4982977 , there is no hard fact that tells us neither in-flight breakup nor steep dive.

The cabin pressure advisory ACARS message can just as well result from erroneous data from the ADR parts of the ADIRUs - which we already know to have failed.

[wes_wall]

there is no hard fact that tells us neither in-flight breakup nor steep dive.


I still believe that the lack of finding a large debris field lends support to the airplane entering the water mostly intact. Had a total failure occured at altitude, and even with a tight pattern of entry, a considerable amount of items would be floating, and by now, distributed over an extremely wide area. This simply has not been the case.

[llagonne66]

Sorry to come back quite lately on a matter that was raised pages ago.
I just needed to access some resources to recover data.
EASA AD F-2002-586R01 requires all Thales Avionics pitot probes P/N C16195AA with S/N lower than 4760 to be inspected to detect the presence of burr that may block the drain holes and as a consequence obstruct the air intake of the probe. After S/N 4761, Thales Avionics has performed the cleaning of the drain hole during the manufacturing process.
This AD refers Airbus SB A320-34-1263 and Thales Avionics VSB C16195A-34-002.
SB A320-34-1354 (first published in March 2006) proposes to change Thales Avionics pitot probes P/N C16195AA by pitot probes P/N C16195BA .QUOTE
REASON/DESCRIPTION/OPERATIONAL CONSEQUENCES Operators have reported airspeed discrepancies while flying under heavy precipitations or in freezing weather conditions. In such an icy and turbulent atmosphere, the aircraft air data parameters may be severely degraded, even though the probe heaters work properly. It appears that the characteristics of such an environment could exceed the weather specifications for which the pitot probes are currently certified. This Service Bulletin replaces the existing pitot probes (FINs 9DA1, 9DA2 and 9DA3) by new probes which are mechanically and electrically interchangeable. Accomplishment of Service Bulletin will improve the resistance against water ingress under severe conditions resulting in improved airspeed behavior. In addition, this new pitot probe introduces a new external protection layer to prevent corrosion.UNQUOTE
SB A330-34-3071 (first published in September 2007) proposes to change Thales Avionics pitot probes P/N C16195AA by pitot probes P/N C16195BA.QUOTE
REASON/DESCRIPTION/OPERATIONAL CONSEQUENCES A320 aircraft family operators have reported airspeed discrepancies while flying under heavy precipitations. A new Pitot probe has been designed to improve A320 aircraft airspeed behavior with these specific weather conditions. A few similar discrepancies had also been reported by A330/A340 aircraft operators and AIRBUS now proposes this Pitot probes improvement for Long Range (LR) aircraft. This Service Bulletin proposes the replacement of the three Pitot probes PN C16195AA (FINs 9DA1, 9DA2 and 9DA3) by new probes PN C16195BA. Accomplishment of this Service Bulletin will improve the resistance against water ingress under severe conditions resulting in improved airspeed behavior. In addition, this new Pitot probe introduces a new external protection layer to prevent corrosion.UNQUOTE
Please note that both of these SBs are RECOMMENDED only, meaning that it's up to the operators to decide upon the embodiement on their fleets.

To conclude, P/N C16195 has been improved by Thales Avionics to cope with some minor (because no AD was raised to cover those two SBs) in-service issues.

Therefore, the various retrofit campains that have been mentioned in the previous pages are led on a volontary basis by the operators.

No TFU on A330 airspeed discrepancies has been published by Airbus meaning that, even if some incidents have occured (see Air Caraïbes above), it was not on a widespread basis and/or no major safety issue was identified.
Hope this clarifies.

[Flyinheavy]

I found it very interesting to read the Euro Cockpit site, that Milka posted in posting #610.
I would think some people involved with Airbus technic are manifested there.

The main message: The fault msg about the pitots was the first and everything thereafter a consequence.

To the somehow more precise map of the SAR search area:

Did anybody notice the positions "AF447 ultima reporte" and ACRS 0214Z. They are 27 NM apart or 3,5 minutes with a presumed GS of 470kt.

Am writing this, because I do not understand the term 'AF447 last report', it is more or less the point wher ACARS transmitted the first patch of msgs.

[PlatinumFlyer]

I respectfully need to disagree. Take a quick look at post 648. At the bottom center of the fin, you will see a little 'hook'. This is part of the center attachment point (the bottom half is gone) and a bolt would have run through it.

Now google "AA587 and photographs". Close inspection of those photos will show that the damage is remarkably similar.

This suggests perhaps that the loss of the rudder limiter allowed the rudder too much motion and ripped the fin off, during transition throught the storm. If it did, then the result is probably the same as AA587

[stepwilk]

If the aircraft entered the water in "a steep dive," I doubt they'd be finding intact bodies, of which they've currently recovered something like 16.

[theamrad]

Andy S - you’re not the only one
Unfortunately, this thread is decaying into utter chaos again. Someone mentioned before that it was starting to look like Airliners. Net. Personally, at times, I think this looks worse than the equivalent there.

This, inspite of numerous warnings from the MODS – and also from other Pruners (i.e. PJ2 and Rainboe, for example. )

In the eight pages growth while I slept, there is precisely nothing new or even interesting; what I read is manufactured, regurgitated (because someone was too lazy to read the thread - the Vazquez presentation is cited at least five times) or picked out of thin air.

The thread is bulging with explanations to the newly-curious about why in many cases their wild notions about what happened are wrong.PJ2 really hit the nail on the head concerning the regurgitating of the same stuff again and again ad nauseum. Such as repeated postings of “the original acars list”, “the ‘updated’ acars list” or Tim Vasquez’s Meteorological analysis . (something around 15 times between 2 threads).
The thread title is AF447 – NOT ‘BASIC Meteorology for student PPL’s 101 or BASIC principles of flight for the uninitiated.


What I find intringuinly is why this forum is banning pilots who weekly fly the leg SouthAmerica - Europe on AB330/340 and knows very well what they are talkin´ about...


Would that be referring, in part at least, to the numbties who needed to be told what pressure altitude means, or possibly what the relationship defining MACH number is, or even why it had to be a b*m* because it dropped off’ radar and wasn’t squawking 7700(!!!!)????:ugh::ugh::ugh:


However, be aware that from now on, any posts with content that is considered by the moderators to be based on un-attributed sources or more importantly theories from anyone without a proper understanding of LH, heavy metal flying will be deleted and the poster banned from the thread for future posting. We will decide on who has a realistic understanding of those criteria by reading what is posted and using our own experience as current airline pilots and crew who do LH flying on heavy metal.
mods


I made my first post on the subject of AF447 - about the use rad altimeters as back up - about 10 minutes ago. . . .. . . . Its was removed. What is going on here?
:ugh::ugh::ugh:


For new people, who just won't bother to read the whole thread (and I know it is long,) or who don't have time, a good summary of what we've been covering is here: (and you should read it!)

Captain Crunch – Not a bad job at all. Interesting to note that despite the caution concerning constant change and a ‘story’ that is rapidly evolving– there are a couple of folks there (I think aptly might be referred to as wiki editor pedants) who object(esp on grounds of ‘original research’) while managing to demonstrate a lack of relevant knowledge akin to some of those posting drivel here while trying to masquerade as pilots or aviation related pros.


Also apparent lack of damage on the side and leading edge has some implications but I don't intend to be the first one to write it down on the PPRuNe.

I think I know what your getting at – but I wouldn’t see what you say as being indicative either way just yet. Of course, I hope (forlornly) that the speculators won’t start off………..wasted hope – me thinks! Nonetheless – we’ve already had – It’s the full vertical stabilizer……it isn’t ……it is……it isn’t………:bored:


Scriabh – I’m not an airbus expert – but if you ask on the Tech forum, I’m sure some of the Airbus types would be happy to explain.

[flyer58]

Couple of years ago over Indian Ocean flew into a bubble of warm air, (just a whisper of cirrus clouds), A342 stopped flying and had to descent 4000' into clear air. About 15-20 min later temp recovered and were able to climb back to FL370.

On the other side, FL410 over the Alpes 18 months ago, light A346 (close to TOD), TAT decreased for 15 degrees and a barber pole just jumped down, leaving us with overspeed warning for 10-15 seconds, thrust on idle, just sitting there and enjoying the horn. Clear air.

In 15 yeras of long range flying happened to me twice. Although not common, sudden temperature variations are possible.


Closer to subject, third pilot was not present in the cockpit at that time for sure - somebody mentioned that he might have been sending ACARS massages. Third pilot (or a pilot) was in the bunk at that time, 4 hrs into the flight, and probably unable to reach the cockpit at all. Could have been captain himself, as far as we know.

[Will Fraser]

Without Rudder deflection limit at M.80 and with power available to deflect it, the assembly (Rudder and Vertical Stabiliser) would have parted the fuselage, given sufficient angle. (AA). Here, 447,"Inflight break-up" may have been limited to the loss of R and VS as a unit. Because the part is missing does not guarantee the disintegration of the rest of the Airframe.

I too think that ACARS is post event. My inkling is that the game was up at a/p disconnect and "Alt.Law". a/p disc., Alt. Law, excessive Rudder.

Aside. A rudder is nice, it trims the a/c. Without it, things are not nice, but survivable. Without a VS, controlled flight is virtually impossible.

So why does the Rudder always seem to take the VS with it when it exceeds its structural limits? Had AA only lost its Rudder.....?

[Mercenary Pilot]

Some picture visuals show clearly and with no doubts .. the fracture of the vertical stabilizer is not situated at the base (connection of the stabilizer to the fuselage)

Again, I completely disagree.

The remains of the attachment lugs are visible at the bottom of the fin, the different colour of the protective coatings is also clearly visible in this area(its a sandy yellow/brown colour) and as already mentioned, the white line where the blue and red logo stripes finish is also visible and is both perpendicular and of equal spacing.

There is damage to the rear of both the fin and of the rudder.

Also, it might help if people would refrain from photo shopping images from the crash site.

[connector]

On ground low power is applied to the probes.
(at least one engine operating)
In flight it changes to high.
Probe caution light can be a spurious failure+
can sometimes be reset.
Companys like Goodrich,Thales or Gsis are manufacturing probes.
All of them can fail (heating elements).
Has nothing to to with FBW.
In recent years two 757 are crashed, due to airspeed
failure, caused by the same problem.

[ankh]

> Tim Vasquez knows enough to state with confidence that thermal
> bubbles with 20-30 K higher temp

"Bubble" refers to a thermal rising. That's not the concern around a cumulus that penetrates into the stratosphere.

Tim Vasquez has amended his web page since -- someone sent him a reference.
Google penetrative cumulus stratosphere temperature

The stratosphere is relatively much warmer air, and dry; that air mass gets displaced when a cumulus penetrates significantly up into the stratosphere.
It's bubbles going _down_ around the edge of the cloud that are the concern.

"It's what you do know that ain't true that will hurt you."

[Graybeard]

"..In recent years two 757 are crashed, due to airspeed
failure, caused by the same problem.."

The AeroPeru 757 static ports had been taped over for skin polishing on the overnight, being undetected when plane unexpectedly put in service, due to a 727 aog. I don't remember if the pitot tubes had been sealed as well, but it is immaterial, as without accurate static, the airspeed indication is misleading. The pitot probes did not fail or ice over.

In a simpler plane, inaccurate airspeed indication is not a killer. Perhaps someone could list the systems adversely affected by inaccurate airspeed indication in the A330.

!. Mach/IAS Hold, of course
2. Rudder Travel Limiter
3. .

GB

[Fly-by-Wife]

Mercenary Pilot ,

A further confirmation that the picture shows the entire VS & rudder assembly is that the start of the change in angle of the leading edge of the VS is clearly visible in the original photo (not so obvious in the extracted picture).

FBW

[deSitter]

I'm at a loss to understand this obsession with the air speed indicated. The VS/rudder assembly has popped off completely intact with the rudder still functioning (you can see it deflected to starboard in the second linked photo), an even more dramatic event that AA 587. It seems to have been found off by itself (else other floating composite debris would be seen). It seems pretty clear that this is the same scenario as AA 587 - perhaps heavy rudder input during a rough patch. Once the tail and rudder were gone, the plane would starting yawing back and forth until controlled flight was lost, with obvious effect on the air speed sensing.

-drl

[737only]

Look at the pictures from the A320 down in Perpignan.
The vertical stab was also detached upon impact and was found floating in one piece. It did not detach in the air obviously....

[captainflame]

1 - The date stamp of the LAV CONT message is from the evening before (2245)

From a pilot prospective and arguably by just looking at the failures on the list:

2- One ADR failure is NOT consistant with flags on PFDs. (airbus eliminates 1 erroneous data source if 2 others are the same, transparently to the pilots)
BUT
Two ADR failures is ! and the ECAM message would read:

3- NAV ADR DISAGREE ! which we find in the list.

4- which in turns get the Airbus to revert to ALT LAW without protections (overspeed, and alpha)

5- autopilots, ATHR, NAV TCAS and F/CTL RUDDER TRVL LIM are associated inop items.

6- F/CTL computers (Prim 1 and SEC 1) could then be reset, and recovered (or not) (they receive wrong data from ADRs)

We're left with the STBY probe, feeding directly (no ADR) the ISIS (self contained stby instrument). Which also seems to report faulty info !!

Near Max rec ceiling, the operational airspeed margin on a jet is quite narrow. easy to go to overspeed, or a stall (no protection), especially in very turbulent conditions.
Flight manually assured using good old techniques of "Pitch and Power", in the QRH for "unreliable airspeed"

7- last message on list : ADVISORY pertaining to Air cond/pressurisation MODE Fault, seems to be linked to cab descent rate (unable to cope with a high VS descent to maintain required DIFF pressure !)

Now we'll have to wait for FDR / CVR recovery ! if ever.

[worrab]

The tail's likely to be with the main debris field - otherwise (despite its size) it's a very small pin in an extremely large haystack. Time will tell...

[SASless]

I wonder if the US Navy SOSUS facility at Dam Neck, Virginia provided any information regarding the location of the crash site. They would surely have been able to pick up the sounds of the impact. If seismic sensors picked up the impact ther sonar hydrophone system operated by the Navy would have as well.

That information would be fairly accurate as to location as shown by the system locating the USS Thresher loss site and later the USS Scorpion.

[Will Fraser]

Graybeard

The question is not one of relative complexity of a/c. Pitot failure (even all three "combinations"), is serious, but what is the reaction of the a/c? If in automated flight, what is the prescribed sequence of corrections or accomodations? Does the a/c hesitate, then initiate another 'regime'? Or does it give up, "parameters exceeded" and quickly revert the a/c to hobbled control inputs after automatically disengaging equipment that the two pilots have quite understandably grown to grant their immediate trust? Three separate computers? Excellent!! Some trained for reversion sequence with immediate and automatic displays?? NO??

Why is the Rudder attached so firmly to the VS? A Rudder is a trimming device. Without a Rudder? Quite flyable. No VS?? You are going down.

[Dysag]

The rudder travel is limited at high speed to prevent the AAL situation. If the airspeed indication is no longer reliable, then there'll be no reliable rudder travel limitation.
Hence the ACARS message.

[Dani]

My last post has been deleted (again), so I have to post it, because I think it is an important information:

The vertical stabilizer broke this way because it is designed that way. It is hold by several titanium bolts on top of the rear fuselage. The fin itself is designed much stronger than the bolts. So either the fin remains on the fuselage or it breaks. If it breaks, it breaks exactly there.

The AA587 was an A300 btw, not an A330.

Dani


You mean your last post (#665) that is still there?

Duck
Moderator

[connector]

GB

1996 Birgenair TC-GEN

[DC-ATE]

Flyinheavy -
But I am damn sure, that they had all legal requirements fulfilled.

I never questioned whether they had the "required" fuel or not, merely that they might not have had the Contingency Fuel that I and others might've had aboard that night considering the wx enroute.

[Will Fraser]

I would like to challenge an engineering response at this point.

My suggestion is that the weak joint should be Rudder/VS, not VS/fuselage.

[atakacs]

just a thought: assuming you are flying a FBW bus and for some reason (say botched paint job in Perpignan, icing mid-Atlantic, faulty wheel on ground sensor in Warsaw) you get all sort of spurious sensor data confusing the - admittedly redundant and fault tolerant - automation. What can you do to regain basic flight control ? I pretty sure that the A330 will behave just as the 320: it's possible but complicated (no big "red button" to kill the automation) and probably not taught in standard training... Even if it quite literally saved the day in many unreported cases I wonder what will be the public perception if it turns out that automation was a contributing factor here...

[Interflug]

There are three pitot probes on the A330, according to ACARS. One on each side at the front I know. Where is the third?

Is it possible that the VS breaking away from the fuselage in extreme turbulence beyond certification limits as initial event would cause a chain of events that are consistent with the ACARS messages we know? I doubt it but the picture of the VS in one piece will certainly cause rumors. So it would be better to face them proactively, if possible.

Is the haste and big PR regarding the exchange program for pitot tubes maybe a little too much...?

[FE Hoppy]

http://www.fab.mil.br/portal/voo447/FOTOS/080609/foto_2.jpg

from the same source as the previous 2 photos.

[Fly-by-Wife]

Dani

The vertical stabilizer broke this way because it is designed that way. It is hold by several titanium bolts on top of the rear fuselage. The fin itself is designed much stronger than the bolts. So either the fin remains on the fuselage or it breaks. If it breaks, it breaks exactly there.

I think I understand the point you are trying to make, but you certainly have it the wrong way around.

The VS is held, as you say, by bolts to the rear fuelage. However, the bolts are far stronger than the VS, and (as in the case of the AA A300), the bolts remain in their mounting brackets, still attached to the fuselage, together with the broken ends of the VS lugs.

Yes, the VS tends to break at this point, but it is not "designed" to do so - it is simply the weakest point / link in the assembly.

HTH

FBW

[DC-ATE]

Regarding separation of the Vertical Fin on Airbus aircraft:

I find it hard to believe that without the "protection" that is normally provided by computer on these aircraft, that a pilot could exert enough force with his feet on the rudder pedals to cause the separation of the vertical fin no matter what the IAS ?!?! I guess I just remember 'driving' my good old 'truck', the DC-ATE !

[DespairingTraveller]

Fly-by-Wife:
A further confirmation that the picture shows the entire VS & rudder assembly is that the start of the change in angle of the leading edge of the VS is clearly visible in the original photo (not so obvious in the extracted picture).

Indeed. It seems to me that people are not taking into account the foreshortened view of the assembly in the original photograph, caused by the angle from which the photos were taken.

If you look at the circle of European stars at the top of the stabiliser in the original photo, the "circle" appears as an ellipse with a major to minor axis ratio of about 2:1. Correct the perspective in Photoshop or similar to render the EU logo circular, and you will find that the assembly quite clearly appears complete with the correct profile for a 330 VS & rudder.

[Will Fraser]

DC-ATE. You had power assisted cables, 330's have hydraulics, powered by enormous energy controlled by "feet" that could deflect the Rudder a disastrous amount in the wrong "LAW". F/O AA587, "pumping the pedals", or 447 w/o limited travel but plenty of authority? See?

Refer #693, above

[DC-ATE]

Will Fraser -
DC-ATE. You had power assisted cables, 330's have hydraulics, powered by enormous energy controlled by "feet" that could deflect the Rudder a disastrous amount in the wrong "LAW". F/O AA587, "pumping the pedals", or 447 w/o limited travel but plenty of authority? See?

Well, I guess I understand what you're saying, but I fail to see how that is "progress".

[plane-g]

This is my first post, but I'm a long time reader and I think I can contribute some information. First of all, compare the pictures of the recovered stabilizer with this one: http://www.eads.net/800/en/gallery/airbus/airbus_selection/airbus_selection.html?display_media=/xml/content/OF00000000400004/9/54/42002549.jpg

If you look closely, you will see that the stabilizer is indeed fairly intact and the part with the mounting points is also still there (though under water). So obviously it must have been that bolts that failed, the stabilizer didn't break apart. Only a small part at the rear is missing.

I guess it's plausible that the stabilizer detached when the plane hit the water. I would like to point out though that the radio antenna is located in the vertical stabilizer, so the crew would have been unable to use the radio if the stabilizer had detached during flight, while the Satlink ACARS messages would still have worked. Not drawing any conclusions, since that's up to the investigators and, also we don't even know where they found the stabilizer, and there could be a thousand other reasins why the crew didn't use the radio, but still an interesting fact.

[Will Fraser]

It's only progress (it is) until the newer system "fails" catastrophically.
The argument is FBW, a topic I know you are fluent in. As in AA587, the system "allowed" for too much travel, and the PF wasn't in tune with his a/c. The flaw is and will always be interface. Here, the a/c was established in high cruise, something happened. The VS/R assembly parted the fuselage, unknown when. The transition from established cruise to a handful of weasels happened when the a/c "sensed" a parameter excursion, and undid the a/p a/t, etc. reverted to "ALT Law", and as much as said, "your a/c". Since tha a/c could not be hand flown at this point, (demonstrably, with two highly experienced airmen seated in the chairs), one must question the disconnects and the survivability however flown, either by automatics (which "quit"), or by the humans.

[DC-ATE]

It's only progress (it is) until the newer system "fails" catastrophically.

I rest my case.

[Mercenary Pilot]

As in AA587, the system "allowed" for too much travel, and the PF wasn't in tune with his a/c.

Pure speculation, there is absolutely no evidence to support this!

[Will Fraser]

mp, The statement refers to facts in evidence. If you have a parsing disconnect, or vocabulary criticism, that's another thing. It is not intended as a conclusion re: 447

[Grunf]

Will,

Maybe too much going into the v/stab failure, at this time...other issues should precede the structural failure, like on other commercial (transport category) airplanes.

Further, any statements on the "weak point", pre-designed failure location on the structure etc are moot simply because this is not the design process. Sadly, accidents will show you what really is the "weakest point".

For that matter, failure during the certification related ground tests for the structure is not expected/required.

So, for the structure, in order to fail you need a catastrophic event.

Cheers

[Safety Concerns]

It is quite shocking that after 600+ posts here and 1900 on the previous thread that persons claiming to be pilots still cannot grasp the fundamental differences between pitot, static, TAT probes, AOA sensors, attitude references and air data references.

It may be a good idea to lock this thread and start again because last time the mods did that it did make a difference for the first few hundred posts.

[Mercenary Pilot]

mp, The statement refers to facts in evidence

There is absolutely NO evidence to support the tail breaking away in flight or the pilots over controlling or exceeding the ultimate loads.

[tubby linton]

Will Fraser,AA587 showed that even a conventional aircraft such as an A300 cannot be flown without a vertical stabilizer and the only case that I know of a jet aircraft that survived the loss of a VS was a B-52 that lost the majority of its VS in severe CAT in 1964.
The problem with AA587 ws the use of full or nearly full opposite rudder inputs.To quote from A300-600 fcom bulletin 827/1 "Such inputs can lead to loads higher than the limit,or possibly the ultimate loads and can result in structural damage or failure".

[Will Fraser]

AA587, I'll reread. tubby, that is my reference.mp, post the rest of my comment please. You are out of context

tubby I thought I made it clear re: AF447, and the rudder. It is as you say.

[Mäx Reverse]

I would like to point out though that the radio antenna is located in the vertical stabilizer

Wrong. All VHF Antennas are mounted on the fuselage, VHF 1&3 on top and VHF2 below. Check out smartcockpit.com (http://www.smartcockpit.com/pdf/plane/airbus/A330/systems/0001/) (page 4 / antennas location) before posting such nonsense.

Regards,

MAX

[Fargoo]

Max,
HF antenna is in the fin.

[Dysag]

MP, Will's punctuation makes it clear that the AFR PF was not in full control:

"As in AA587, the system "allowed" for too much travel, and the PF wasn't in tune with his a/c"

Except that's not what he meant, its just the way they speak in Petaluma.

He meant that the AAL pilot wasn't in tune....

[Will Fraser]

Dysag. thank you.:ok:

[abkasti]

Captainflame
But the plane left Rio at 31 may, at 22:00 gmt so it seems that the
LAV CONT message were 45 mins after the liftoff - or maybe i dont get it.? Had to register to ask this, have looked at the event for some time now, what does it mean ?
FR0905312245 38310006vsc x2, ,,,,,LAV CONF


1 - The date stamp of the LAV CONF message is from the evening before (2245)

[grebllaw123d]

Interflug,

Acc. smartcockpit.com section Navigation 34.10 page 2, the third (STBY) pitot tube is located on the left side of the nose, close to capt. pitot tube.

bgds

[ttcse]

Just a point of distant data on vertical stabilizer breaks, the vast majority of a vs broke off a B52 in the US while flying thru rough summer weather at altitude around 1970. While they did complete their flight under the declaration of an emergency, they weren't aware how little vs they had remaining.

On AF447 I see nothing conclusive about how/when this one came off.

[JABBARA]

CALENDESTIONO Post 654
"Oh, and IR needs TAS input to keep itself upright.:"


Are you sure this is correct?

[Svarin]

Gentlemen,

two cents regarding the loss of Rudder Travel Limiter, I stumbled upon a document which was put online by Eurocockpit - Accueil (http://www.eurocockpit.com). The document in question relates to a pair of serious incidents with loss of pitot probes on A330s, company Air Caraïbes Atlantique (ACA). Makes for a fascinating reading (in French).

The ACA incident produces a series of failures that are strikingly similar to what is deduced from the ACARS document we use as foundation for study here.

Full document at http://www.eurocockpit.com/docs/ACA.pdf.
The document looks very solid from a technical point of view, full of nitty-gritty details, made after meetings between ACA people and AB people.

Back to RUD TRV LIM :

(Can't insert picture here... Anyway... Here is the gist of it, roughly)

As CAS becomes unavailable, maximum rudder deflection is 'frozen' (gelée) at about 10 degrees, however full rudder deflection will be recovered when SLATS are extended.

Since SLATS extension is purely mechanical (not linked to air data), we can reasonably conclude that a form of rudder limitation still exists (albeit a very primitive limitation, 10 degrees deflection) in the AF447 configuration.

Now is this 10 degrees limit useful in the situation ? At Mach 0.80 or so, would a full 10 degrees deflection be already too much for structure ?

Is the limit counterproductive ? I would like full deflection if I had to get out of a spin for example.

[SteamCat]

Hi. Ex Nav here. Sosus is gone, a casualty of the Clinton years. We now use towed passive arrays, which, if there was a vessel at sea, might have picked something up. Best regards.

[SteamCat]

I have never driven an Airbus, but it has been mentioned on here that stick imputs from both sticks simultaneously in some Law conditions results in additive input (ie, if both sticks deflected left, input is doubled, if one left and one right, input is cancelled). Is this true? If so, does it hold for rudder inputs as well?

[TripleBravo]

ADVISORY pertaining to Air cond/pressurisation MODE Fault, seems to be linked to cab descent rate (unable to cope with a high VS descent to maintain required DIFF pressure !)No point. As demonstrated, wrong air data from ADIRU are enough to trigger the actually transmitted advisory! Why is this a professional forum, when there is only media blurb considered and re-pasted? (Sorry to the guy from whom I took the quote above, does not mean any negative, just an example.)

But please all, read some posts here before re-posting wrong "findings".

What is the point that some posters even dig deeply into actual aircraft manuals and actual system definitions and / or contributing their actual hands-down experience, when their careful thoughts and findings are buried by meanigless chatter from worthless media repetitions?

Yes, could have been a steep descent, as it could have been anything by now, but you simply cannot conclude this from the ACARS data. (As well the often cited "TCAS antenna fail" is simply wrong, but posted over and over again.)

CALENDESTIONO Post 654
"Oh, and IR needs TAS input to keep itself upright.:" That is of course incorrect. As this is intended to be a professional forum, please either inform yourself ahead of posting nonsense or ask this as a question.

[tubby linton]

Svarin in the fcom that I have it states the following:

Each (Rudder)limiter channel is controlled by its associated SEC.In case of a double SEC failure,the max rudder deflection stays at the value reached before the failure,then max deflection is available at slat extension.

[mingocr83]

@ Steamcat

That is true... dual inputs from the sidesticks is not good to Fi-Fi

[bsieker]

I have never driven an Airbus, but it has been mentioned on here that stick imputs from both sticks simultaneously in some Law conditions results in additive input (ie, if both sticks deflected left, input is doubled, if one left and one right, input is cancelled). Is this true? If so, does it hold for rudder inputs as well?

Side-stick inputs are summed, but limited to the maximum deflection of a single stick. E.g . in roll in normal law, maximum stick deflection demands 15 deg/sec roll rate. If both pilots make full left stick inputs, the demand is still only 15 deg/sec. One pilot making a full left, the other a half-right input, the result would be half-left.

Ruder pedals are different. They are mechanically linked and always control the rudder deflection directly (limited by the travel limiter).

(The rudder is also moved by the FBW system for turn coordination; I am not entirely sure FBW-commanded rudder movements are backdriven to the pedals.)


Bernd

[connector]

Interflug, correct me if i am wrong.
In my view ACARS is a "messaging system".
Not like a CFDS.
Or a QAR- recorder in parallel with the DFDR.
When ACARS tells you "probe-failure" it does not tell you, what probe fails.
Thats how it works on most airplanes.
My humble oppinion.:)

[Flyinheavy]

@Tubby:

I think Svarin is right, the report states:

la valeur maximale du debattement est gelee a 10°

the value of max rudder is frozen at 10°

You are right about the rest.

But this report of Air Caraibe shows the very same Ecam msgs and wrngs that were generated in the AF case, if one reads the ACARS msgs. Up to contradictorial informations to the Crew about Stall Wrng. The Cpt decided to ignore them as was written on an other part of the Tecn.Infos that those pilots used.

It is very interesting to read this report, seems to show a probable scenario.

[Bill Bader]

I think the rudder conversation is mostly just conversation; I doubt you can deduce much from speculating about the photos. The power of moving air is much greater than people realize—I've seen avalanches in the Canadian Rockies snap whole pine forests downslope like toothpicks: but in truth it was not the snow breaking those trees; it was the compressed air preceding the snow. The air by itself was snapping hundreds of tree-trunks in just a few seconds.

I think, whatever AF447 wreckage is found, the wreckage itself is likely a final result, and if you had half a dozen hypothetical scenarios which had similar causes, the way the plane fell—through such turbulence and from such a height—and what stayed together would vary considerably. Like any two leaves falling from a maple tree, I would suggest.

[PJ2]

The discussion on the VS implies a "breakaway line" or a fracture some distance from the attach points on the fuselage. I have taken a close look at the photos supplied earlier today and have enlarged one section, (lower, center) of one photograph to see if the structure in the middle of the photo is a mounting lug or if it is part of the recovery gear etc. I have inserted a photo of the AA587 fin lug for comparison.

I am not suggesting or concluding here but using the newly-available photos to examine further evidence of how the structure fractured. Although the alternatives are fairly limited, nor can we draw conclusions about how, when or why the vertical stabilizer is separated from the main structure. I am merely trying to identify a possible attach point to possibly address the partial failure suggestion seen a few posts back. PJ2.



http://img4.imageshack.us/img4/2629/aa58709.th.jpg


Imageshack - vsertstablugdetailposco.jpg (http://img190.imageshack.us/i/vsertstablugdetailposco.jpg/)

http://img4.imageshack.us/img4/418/vsertstablugdetailposco.th.jpg



...in "negative" form, for slightly better clarity:

Imageshack - vsertstablugdetailnegco.jpg (http://img8.imageshack.us/i/vsertstablugdetailnegco.jpg/)

http://img4.imageshack.us/img4/2826/vsertstablugdetailnegco.th.jpg

[Diamond Bob]

Yes, the VS tends to break at this point, but it is not "designed" to do so - it is simply the weakest point / link in the assembly.



Yes, that would be quite a design feature all right. Let's just let the tail fall off to save the rest of the aircraft!

[Dutch Bru]

I would concur with those posters theorising that the VS broke off in its entirety on impact and I would add: of a by and large intact a/c.

Looking at the VS photo's, I dare to argue that the a/c impacted more or less level flight, but at a very high AOA, making the very end of the tail section hit the water first, crunching the tail section upwards and in the process damaging the lower-edge of the rudder and unsettling the VS attachment. Subsequent impact of the main, more forward a/c sections would then arrest the forward movement of the VS to the point that it separates from the tail-section alltogether.

Just theorising on what material is available at present.

[BigHitDH]

I'm looking at the tail section right now, it seems surprisingly undamaged except for the rearmost section. If it were to "peel away" in the airflow, that's where I'd expect damage to be as it made contact with the empennage.

Question for those familiar with type, are all attachment points for the VS aft of the pressure bulkhead? I'm assuming they would be.

[ManaAdaSystem]

Why would they be pumping the rudder to it's max during turbulence? To me, turbulence is mostly about pitch and roll, not so much about yaw. For sure, on those occations when I have been hand flying in turbulence, the use of rudder has never been needed. Then again, I've never been in severe turbulence.

An upset recovery could trigger full use of rudder, but mostly in a nose up, low speed situation. It would not need "pumping" in this situation.

This aircraft fell out of the sky. Bits and pieces are known to fall off when this happens.

On the issue of fuel (or lack of), I can safely say that I have never been in a cockpit where this has even been discussed when faced with a diversion around weather. It simply doesn't cost that much to deviate 20-30-40-50 miles around weather.

[Dani]

I don't get it!

Now that we found the vertical fin, we are speculating about this part as the primary cause of the accident or the first part that fell off. What if we found a door first? Would we argue then that it was a door that fell out first and destroyed the plane?

The reason why they found the fin first is because it is one of the very few parts nearly completly made of composite materials and thus floats (better than the rest). On most accidents over water they find the fin first (remember the Armavia A320 near Sochi, Russia, May 3, 06). Nearly always intact.

Those fins depart from the fuselage (for whatever reason) and "fly" like a feather earthwards. That's why they don't get destroyed on impact.

Dani

[lomapaseo]

The addition of photos to this thread sure does focus the attention of many and provides fodder for speculations way beyond the evidence at hand.

Consider always the #1 rule of observation

Occams Razor

e.g. the most likely explanation for the visual appearance of a piece of debris at a crash site is the impact with the ground.

the most likely explanation .....etc. of a field of debris away from a crash site is a cascading breakup.

The finding of an eureka cause in a single piece of debris is extremely remote.

To extrapolate that single photo to design and operational characteristics of the A330 is quite a stretch in my opinion.

[DC-ATE]

ManaAdaSystem -
To me, turbulence is mostly about pitch and roll, not so much about yaw. For sure, on those occations when I have been hand flying in turbulence, the use of rudder has never been needed. Then again, I've never been in severe turbulence.

Exactly.....there's no need to apply any rudder. You basically hang on. I've been in extreme turbulence (that's right...more than 'severe'). However, it was in a DC-6. I was flying and all I could do was just try and keep it more or less straight, but level was the most important part. Didn't really care which direction it went. However, I do not think a jet transport of today's manufacture would have survived that encounter.

[Orestes]

My expertise is in aircraft engines (20+ years gas turbines) , but not airframes.
A question for those with real expertise with ACARS: Would it report any problems with the hydraulic systems? It would seem to be fairly safe to assume that all hydraulic lines leading to the rudder actuators would have been severed upon loss of the vertical stabilizer. Since ACARS did not mention anything related to hydraulics in its stream of error messages, would it then be reasonable to assume the stabilzer was still with the aircraft during that time? Or, is hydraulics simply not a system monitored by ACARS?

[grizzled]

dani -- Thanks for that . It was needed.

lomapaseo -- Same comments as to dani above. (With the proviso that your reference to debris fields and cascading breakups is directly relevant to "ground impact" but significantly less so in this case of an ocean impact followed by a week of winds and currents.)

[PJ2]

ManaAdaSystem;
Why would they be pumping the rudder to it's max during turbulence?
Where on earth are you getting that from?!

There is certainly no evidence nor even a suggestion that "pumping" the rudder was done. Stick to what is available.

(Why do I post here at all for heaven's sake?....).

Dani - there is NO suggestion nor should there be, as to how/when/why the vert stab came off. It is off and that is the only evidence we have before us. Your swatting at flies that don't exist.

lomapaseo;

I believe we agree here. There is no "eureka" suggested of course. I state my intent very clearly and warn that drawing conclusions cannot be done. I am trying to contribute to knowledge by examing "what is" and nothing more - we simply cannot do more without allowing imagination to take over from facts.


I have to say in general, that there is once again, great hazard in posting any suggestion or comment with reference to anything new coming in. At the slightest suggestion some ride off in all directions setting their hair on fire about all and unrelated sundry over new comments. Let's stick to what is known, which is extremely little. To give life to theories only serves interests which may not have the same goals in mind...

[BigHitDH]

PJ2,

I don't think ManaAdaSystem was suggesting that, I think it was a question, not a statement!

[ChrisVJ]

Simply can not tell whether Stabiliser came off in flight or at impact from the pictures, however I suspect there is a good chance they may be able pin down a good estimate when it is carefully examined. The way everybody is amking announcements (though n ot always accurate) there is a good chance we'll hear what the likelyhood is when they get it back to land and examine it.

As a PPL and not anything to do with engineering either I was slightly astonished on learning of the standard set for stabiliser attachment after the AA chrash. I realise this is not just an Airbus thing too, and perhaps the engineering required to fix structure for high speeds would be just so out of order that travel limiting is the only reasonable option.

However looking at the type of attachment, rather like that fixing a keel on a high performance sailboat, one can not but be concerned at the moments and leverage involved and wonder why, if it is attached behind the after pressure bulkhead, they did not go for a lower leverage design with loads spread between the upper and lower fuselage construction.

[vapilot2004]

In normal cruise and climb, even through turbulence, the use of rudder is limited. On this particular aircraft, yaw control is augmented by the FBW system and yaw damper.

While the ACARS readout does show a degradation from Normal Law to Alternate Law, and the warning regarding the Rudder Travel Limiter (most likely from the ADIRU failures), there is no reason the PF would from that point forward have begun stomping on the rudder pedals willy nilly.

To suggest otherwise is irresponsible at this point in the investigation. Speculation is fine for a learning exercise, but let's refrain from pointing fingers at the crew when not even 1/1 millionth of the data & facts are at hand.

[ManaAdaSystem]

People are speculating that the lack of rudder limiter had something to do with this accident. The lack of rudder limiter will not break the fin off, you would need to apply a lot of rudder (pumping is maybe not the best word) to do that, like in the AA case.

I just don't see why they would have to do that, that's all.

You're starting to sound like Rainboe.

[Fly-by-Wife]

there is NO suggestion nor should there be, as to how/when/why the vert stab came off. It is off and that is the only evidence we have before us.

With respect PJ2, I believe that some conclusions can be drawn from the failure of the VS / fuselage connection seen in the photographs.

A simple knowledge of mechanics tells us that a large sideways force was exerted on the VS at some unknown instant, generating a bending moment sufficient to fail either the bolts or the lugs (or a combination of both) holding it to the fuselage. It is not clear from the photographs whether the lugs or the bolts failed.

That sideways force could have happened towards the beginning of the sequence (as in the AA A300 accident), or at the point the VS hit the water, or any point in between. Time will tell.

The VS is a vertical cantilever. The VS failed at the point of greatest bending moment, occurring at the base of the cantilever (point of attachment to the fuselage).

From a simple analysis of the geometry of the complete VS / fuselage connection, there is no other plausible failure mechanism that explains the failure shown in the photograph.

Added - ChrisVJ, you posted while I was writing, I am very much in agreement with your thinking, particularly your last paragraph!

FBW

[Safety Concerns]

Or, is hydraulics simply not a system monitored by ACARS?When ACARS tells you "probe-failure" it does not tell you, what probe fails. Thats how it works on most airplanes. My humble oppinion.http://static.pprune.org/images/smilies/smile.gifPeople are obviously having problems understanding acars. ACARS is a communications system that relays messages. It can be considered as an onboard fax machine and is completely independent of any onboard fault detection system. One of the more useful additional functions is to relay messages from the CFDS system. Therefore ACARS influences nothing. It doesn't decide which fault messages to send, it only sends those that are reported by another system.

So yes it will tell you which probe has failed and it will relay hydraulic, fuel, oxygen and any other message that CFDS has stored. It is also very useful when drivers start telling porkies about faults occuring on a home leg.

Thats why the information is useful and relevant. However it has a few drawbacks too. One good example is AP off. AP off will be reported but you cannot tell if it was a manual disconnect or an automatic one. Although in this case considering the amount of failures it would be reasonable to assume it was automatic but we don't know that.

Any warning that appears on the ECAM system will be stored in CFDS and if the acars option is in use that warning will be sent back to base.

[chucko]

SteamCat---SOSUS isn't completely gone. Used for civilian monitoring (whale farts, NOAA's VENTS program in the North Pacific). Don't know if it's continuously monitored.

[protectthehornet]

avoid bad wx

really know what to do with wx radar

be ready for just about anything, including loss of computer assisted flying, loss of airspeed and changes in flight control limits.

always be ready.

[grizzled]

PJ2 -- Deep breaths . . .

I didn't get the impression that either dani's post or lomapaseo's were referring directly to you or your posts. In dani's case he wasn't at all swatting at flies; he was making (what I thought at least) was an accurate and appropriate comment re some of the speculation of the past day. It seems to me that Lompaseo was doing the same thing.

Grizzled

[deSitter]

It's clearly very unlikely that the VS/rudder assembly broke off during an impact of a complete or nearly complete plane - there would be all manner of debris riding along with the same currents, evidence of hydraulic fluid on the water surface etc. etc.

-drl

[Zeffy]

On this particular aircraft, yaw control is augmented by the FBW system and yaw damper.


Would the yaw damper remain operational following the air data disagreements?

IOW -- would it auto-disengage along with the AP and the downgrade to Alternate Law?

[Orestes]

Thanks for the clarification -ACARS doesn't directly monitor systems - it just relays data from other monitoring systems. You also answered the main question I was asking - hydraulic system problems would be reported to and relayed by ACARS if they occur.

Thanks!

[Fly-by-Wife]

I didn't get the impression that either dani's post or lomapaseo's were referring directly to you or your posts. In dani's case he wasn't at all swatting at flies; he was making (what I thought at least) was an accurate and appropriate comment re some of the speculation of the past day.

Grizzled, Dani seemed to be pretty explicitly stating that he believed that the VS had separated in flight:
Those fins depart from the fuselage (for whatever reason) and "fly" like a feather earthwards. That's why they don't get destroyed on impact.
I think that was part of what PJ2 was getting at.

FBW

[PJ2]

FBW;
A simple knowledge of mechanics tells us that a large sideways force was exerted on the VS at some unknown instant, generating a bending moment sufficient to fail either the bolts or the lugs (or a combination of both) holding it to the fuselage. It is not clear from the photographs whether the lugs or the bolts failed.
Yes, I think so and agree. That was the only reason I wanted to work a bit on the photos of the VS - to see if that one area in the photo was sufficient to show the lug structure or not. I think it does but it's just indefinite enough to cast a bit of doubt so I posted it to see what others thought.

Re Dani's comment, I think that was part of what PJ2 was getting at.
Exactly, and from ManAdaSystems regarding "pumping of the rudder":
I just don't see why they would have to do that, that's all.
Like Rainboe...we'll leave online personalities out of this, thanks. I was blunt perhaps, for which I apologize, but really, you simply don't know that any such crew action took place.

grizzled - thanks. I post only to deal with "what is" because I think it is important to be very careful where conlusions, even one's that seem reasonable, go. Until today, there has not been anything new, ergo, no reason to post.

[connector]

Thanks Safety:)

Good point
It is not a DFDR "yet"

[Lemurian]

That sideways force could have happened towards the beginning of the sequence (as in the AA A300 accident), or at the point the VS hit the water, or any point in between. Time will tell.
There is nothing on those pictures that would tell you anything about "sideways forces"
As a matter of fact, until we see the other side of the fin, evidence points towards a longitudinal breakage : the base of the rudder is broken, hinting at possible compression stresses, whereas the forward part of the fin base shows a more cleanly accomplished separation, this time indicative of tension forces.
With these observations, I could deduct that the moments that caused the fin to shear from the fuselage were directed aft, meaning the tail hit the water first ; an observation that could lead me to claim that either the fuselage broke in mid air in several parts or the entire aircraft was in a high pitch angle on impact...and still hit the sea tail first.
But of course, I won't make that kind of deduction for I'm one of those who would be very careful with too-quick conclusions and await further evidence.

[PJ2]

Lemurian;
There is nothing on those pictures that would tell you anything about "sideways forces"
Yes, agree - we can only, possibly, say that there is a lug (or not) present in the photo.

[ttcse]

Lemurian;
As a matter of fact, until we see the other side of the fin, evidence points towards a longitudinal breakage : the base of the rudder is broken, hinting at possible compression stresses,

Possibly in the chaos the trailing edge of the rudder met with the trailing edge of the HS or some other detached part.

Where are the rudder actuators attached to the rudder? Perhaps that section of the rudder was ripped off.

[Lemurian]

Possibly in the chaos the trailing edge of the rudder met with the trailing edge of the HS or some other detached part.
Don' put words in my typing : My post was just about too-quick interpretations and conclusions and the remarks I made were another possibility, like yours is, so between the posters who see a sideways breakage, and you proposing a far more complicated scenario, where do we stand ?
Nowhere, I think.
Someone needs to summerize the factual infos avaikable, otherwise Danny will get back in with his big heavy boots.

[Grounded101]

Re. abkasti's post # 721. I Would be grateful if somebody could comment on the significance or otherwise of the ACARS message that appears to have occurred 43 mins into the flight - the event with the timestamp 0905312245. Would this coincide with reaching cruise altitude? Understand this is a VSC Vacuum System Controller failure (FLR) with the message 'LAV CONF'. I recall my father telling me he was a passenger on an Indian Airlines A320 in the early nineties that had a cabin depressurisation and had to return to the departure airport - he had noticed early in the flight that the toilet flush was not functioning.

[Fly-by-Wife]

Lemurian,

There is nothing on those pictures that would tell you anything about "sideways forces"
As a matter of fact, until we see the other side of the fin, evidence points towards a longitudinal breakage : the base of the rudder is broken, hinting at possible compression stresses, whereas the forward part of the fin base shows a more cleanly accomplished separation, this time indicative of tension forces.
With these observations, I could deduct that the moments that caused the fin to shear from the fuselage were directed aft, meaning the tail hit the water first ; an observation that could lead me to claim that either the fuselage broke in mid air in several parts or the entire aircraft was in a high pitch angle on impact...and still hit the sea tail first.


As an engineer responsible for designing connections between steel components (and occasionally composite materials), I believe that I am well qualified to comment here.

Here's my reasoning:

The total force involved in breaking off the VS is pressure x area.

The frontal area of the VS is very, very small indeed (there's a reason for that - think about where you want as little drag as possible).

The lateral area of the VS is huge in comparison (there's a reason for that too, when you think about it).

So which of these is going to produce the larger total force?

Next, we move to the geometry of the connection to the fuselage. 2 lines of bolts running fore and aft, 3 bolts per line. The side to side distance is significantly less than the fore and aft distance, so the resisting moment is also far less.

In other words, the fore & aft moment is vastly smaller than the lateral moment, and the fore & aft resistance to failure is greater than the lateral resistance.

Believe me, if this were a fore & aft failure, there would be a huge dent in the VS that just isn't there.

FBW

[robdean]

There is clear precedent for a VS being cleanly broken from an airframe by aerodynamic forces at altitude, and being recovered intact.
Is there precedent for a VS being so cleanly removed at root by impact? Most ways I can imagine in which such lateral force could be applied would tend to damage the fin.

[WNcommuter]

In other words, the fore & aft moment is vastly smaller than the lateral moment, and the fore & aft resistance to failure is greater than the lateral resistance.

Believe me, if this were a fore & aft failure, there would be a huge dent in the VS that just isn't there.

Agreed. However the force could have come from any direction as long as the lateral portion of the force were sufficiently high. For example, a ditching with a significant angle between the aircraft's orientation and its direction of travel would give the tail section a large sideways kick. It need not have been a directly sideways force.

[Dutch Bru]

http://www.pprune.org/4983708-post737.html

Not if you would consider the scenario put frwd in my previous post.

I agree however with PJ2 and others that there are several theories possible. To underline that was at least my implicit intention of my post a couple of pages back, to counter the theories floated by other posters arguing parallels with the A300 accident hardrudder accident.