Air France 447 Reported Missing

[Pratt X 3]

My new favourite theory: Did a Meteor Bring Down Air France 447?
http://blogs.discovermagazine.com/cosmi ... rance-447/

[YHZChick]

Jetmech, It actually works the other way, when at high altitude there is a much smaller margin between low speed buffet {for this thread lets just call it a stall} and high speed buffet{lets just call it exceeding limiting Mach number} In the early days of jet aircraft there were far more hull losses as a result of getting into problems at high altitudes than from bumping into things at low level, if you can track them down there are some execelent movies put out by Shell which were used as training aids in the early days of jet travel, if not there are also some very good books on high speed flight, try to avoid the ones with too much math, unless you like that stuff! In my miss spent youth I flew one aircraft which could go very high, the problem was we only had about 8 to 10 knots margin between the two buffets, comming down took a very long time even with the brakes out.

Great simple explanation of the coffin corner.
Another good explanation (a little more detailed) is here ( http://airplanepilot.blogspot.com/2007/ ... orner.html ) and also on wiki.

Assuming the pitot tubes were not fuctional due to icing (which the ACARS support), and if the crew attempted to fly above an area of CB, stall is a very likely a contributor to this accident.

[YHZChick]

Here's a bit of info on that Ogee:

Airspeed instruments on Air France Flight 447 were not replaced as the maker recommended before the plane crashed in turbulent weather, the French agency investigating the disaster said Saturday.

The French accident investigation agency, BEA, found the doomed plane received inconsistent airspeed readings by different instruments as it struggled in a massive thunderstorm on its flight from Rio de Janeiro to Paris with 228 people aboard.

No confirmed debris from the aircraft has been found and without its black box recorders, aviation investigators have little information to help them determine what caused the crash.

Airbus had recommended to all its airline customers that they replace speed-measuring instruments known as Pitot tubes on the A330, the model used for Flight 447, said Paul-Louis Arslanian, the head of the agency.

"They hadn't yet been replaced" on the plane that crashed, said Alain Bouillard, head of the French investigation. Air France declined immediate comment.

(Full article here: http://www.google.com/hostednews/ap/art ... wD98LA4C80

The directive issued from Airbus re: replacing pitot tubes was issued in 2002. This aircraft left Tolouse in 2005.
http://www.casa.gov.au/wcmswr/_assets/m ... 30-001.pdf

[Widow]

Paris, 06 June 2009 - 23:09 local time

Press release N° 12
Update on anemometric sensors

Following the many questions which have appeared in the media on the issue of the Pitot probes in its fleet (the Pitot probe is an instrument which measures the air speed of the aircraft), Air France wishes to make the following clarifications:

1) Malfunctions in the Pitot probes on the A 320 led the manufacturer to issue a recommendation in September 2007 to change the probes. This recommendation also applies to long-haul aircraft using the same probes and on which a very few incidents of a similar nature had occurred.

It should be noted that a recommendation from the manufacturer gives the operator total freedom to apply the corresponding guidelines fully, partially or not at all. Should flight safety be concerned, the manufacturer, together with the authorities, issues a mandatory service bulletin followed by an airworthiness directive (AD).

The recommendation to change the probes was implemented by Air France on its A320 fleet where this type of incident involving water ingress had been observed. It was not implemented on the A340/330s as no such incidents had been noted.

2) Starting in May 2008 Air France experienced incidents involving a loss of airspeed data in flight, in cruise phase on A340s and A330s. These incidents were analysed with Airbus as resulting from pitot probe icing for a few minutes, after which the phenomenon disappeared. Discussions subsequently took place with the manufacturer. Air France asked for a solution which would reduce or eliminate the occurrence of these incidents. In response to these requests, the manufacturer indicated that the probe model recommended for the A320 was not designed to prevent such incidents which took place at cruise levels, and reiterated the operational procedures well-known to the crews.

In the first quarter of 2009 laboratory tests suggested, however, that the new probe could represent a valuable improvement to reduce the incidence of high altitude airspeed discrepancy resulting from pitot probe icing, and an in service evaluation in real flight conditions was proposed by Airbus. Without waiting for the in service evaluation, Air France decided to replace all its probes and the programme was launched on 27 April 2009.

Without making any assumptions as to a possible link with the causes of the accident, Air France speeded up this programme and reminded its pilots of the current instructions issued by the manufacturer to cope with the loss of airspeed data.

http://alphasite.airfrance.com/en/s01/p ... unique2651

[YHZChick]

Paris, 06 June 2009 - 23:09 local time

Press release N° 12
Update on anemometric sensors

Following the many questions which have appeared in the media on the issue of the Pitot probes in its fleet (the Pitot probe is an instrument which measures the air speed of the aircraft), Air France wishes to make the following clarifications:

1) Malfunctions in the Pitot probes on the A 320 led the manufacturer to issue a recommendation in September 2007 to change the probes. This recommendation also applies to long-haul aircraft using the same probes and on which a very few incidents of a similar nature had occurred.

A recommendation is not the same as an AD.

[Widow]

And the quote I originally referenced said "recommendation" not AD. Did someone else refer to an AD?

[29 ford]

Just my opinion but I doubt it had anything to do with airspeed.

The crew was reporting electrical problems and there was known weather in the area.

If a severe lightning strike occurred it is possible the generators tripped offline which meant they were on the ADG. The ADG is only going to power emergency busses which means no Auto-pilot.

As well if it was severe enough it probably took panels off the tail and/or damaged flight controls.

[canwhitewolf]

Brazil says 17 bodies recovered from jet crash
By MARCO SIBAJA and ALAN CLENDENNING –

RECIFE, Brazil (AP) — Search boats scouring the Atlantic Ocean on Sunday recovered 15 more bodies of passengers who were aboard a doomed Air France flight that crashed a week ago, Brazilian military authorities said.

Air Force Col. Henry Munhoz said four of the bodies were men and four were women. They could not provide the gender of a ninth body Brazilian searchers recovered or of eight additional bodies recovered by French authorities.


http://www.google.com/hostednews/ap/art ... wD98M42G80

[jjj]

This is morbid but usually a clue in determning whether or not there was an inflight breakup but......

were the bodies clothed or not? Inflight breakups sometimes cause bodies to arrive at the scene with clothes peeled away.

[YHZChick]

Just my opinion but I doubt it had anything to do with airspeed.

The crew was reporting electrical problems and there was known weather in the area.

If a severe lightning strike occurred it is possible the generators tripped offline which meant they were on the ADG. The ADG is only going to power emergency busses which means no Auto-pilot.

As well if it was severe enough it probably took panels off the tail and/or damaged flight controls.

An Airbus-driver can correct me if I'm wrong, but I'm quite certain that the AP would have disconnected anyway when the plane went into Alternative Law, which would happen if there was disagreement between sensors (such as pitot tubes/airspeed sensors). It wouldn't have to be the result of an electrical failure.

If they had pitot tube icing (a result of being in CB), the plane would have gone into ALT Law, in which case a stall is a real possibility (particularly if they were approaching/in the coffin corner--keeping in mind that a sudden change of temperature in that storm system may have pushed them there).

I don't think it was any one thing (i.e. a lightning strike) which brought her down, but more likely a combination of several factors (high altitude/stall, icing, etc etc). It does appear that the aircraft broke up before impact, however that could be the result of severe and violent forces during the decent (as opposed to explosion, lightning strike, whatever). The ACARS seem to point to multiple system failures prior to the plane breaking up. Hopefully the FDR will fill in the blanks.

[Rockie]

Just my opinion but I doubt it had anything to do with airspeed.

The crew was reporting electrical problems and there was known weather in the area.

If a severe lightning strike occurred it is possible the generators tripped offline which meant they were on the ADG. The ADG is only going to power emergency busses which means no Auto-pilot.

As well if it was severe enough it probably took panels off the tail and/or damaged flight controls.

An Airbus-driver can correct me if I'm wrong, but I'm quite certain that the AP would have disconnected anyway when the plane went into Alternative Law, which would happen if there was disagreement between sensors (such as pitot tubes/airspeed sensors). It wouldn't have to be the result of an electrical failure.

If they had pitot tube icing (a result of being in CB), the plane would have gone into ALT Law, in which case a stall is a real possibility (particularly if they were approaching/in the coffin corner).

I don't think it was any one thing (i.e. a lightning strike) which brought her down, but more likely a combination of several factors (high altitude/stall, icing, etc etc). It does appear that the aircraft broke up before impact, however that could be the result of severe and violent forces during the decent (as opposed to explosion, lightning strike, whatever). The ACARS seem to point to multiple system failures prior to the plane breaking up. Hopefully the FDR will fill in the blanks.

Alternate law does not necessarily mean losing the autopilot. If you look at the control law reversion table on page 9 of this thread you will see there are several circumstances in both Alternate 1 and 2 that do not result in a loss of AP. Even a loss of all generators will only render AP2 inoperative. The autopilot may trip off initially if the aircraft enters an emergency electrical configuration (for sure if the right seat pilot was flying since they normally engage AP2), but AP1 remains available and can be re-engaged if it trips off.

A loss of airspeed information is a very serious thing that has a much higher potential for loss of control. It is in fact the only "memory" drill in the airplane, but is well hidden and some crews may not even be aware that it is a memory item given Airbus's overall philosophy of ECAM design and discipline. For sure a lot of pilots don't recognize the deadly seriousness of that situation and the difficult and lengthy procedure for dealing with it. It is basically a 4 page procedure, the first section of which is designed to keep you alive long enough to sort things out so they can recover the airplane. It isn't something that is normally trained for since the chances of it happening are so slim. Plus it takes a long time to properly train that kind of scenario, and with all the other stuff that is required by regulation to cover in training most airlines won't spend the time. Hopefully that will change because it is a killer.

This is the first section of the Unreliable Airspeed / ADR check procedure. As Clunkdriver mentions (and he was apparently well ahead of his time) the procedure makes good use of GPS speed and altitude information (along with the IRS). The thing to remember is the large difference in indicated airspeed and true airspeed at altitude, plus the GPS only gives groundspeed further increasing the error.

Losing airspeed information is extremely difficult to deal with even at low altitude with the procedure recently briefed and prepared for in training. At high altitude, at night with no horizon to reference, with degraded flight controls and much poorer handling qualities, turbulence, tired, no recent training (if any) etc....

[Rockie]

Airbus's corporate learning curve since they introduced the 320 has been as steep as the pilots has been Clunk. You hit the nail on the head about their initial dismissive, superior attitude regarding their technology. But the good news is they are much much better than they used to be, and have made great strides in recognizing the "weaknesses" and making the airplane more user friendly for us mere human beings. They still have a ways to go though and we are still learning things about the airplane that they didn't deign to tell us until we asked the specific question. The bad news of course is that the cost of that attitude change is written in lost lives.

Fundamentally though they are great airplanes. Especially the 330.

[canwhitewolf]

CNN talks with an Airbus expert about what might have caused last week's Air France crash.

http://edition.cnn.com/video/#/video/wo ... videosview

[YHZChick]

Pictures of tail section that have been recovered...

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

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

[xsbank]

Such a sad tragedy - just when we think we're getting pretty good at all this aviation stuff, something like this happens to show us how really stone age we still are. Sad times in our industry.

Stay safe out there, try and learn from all who've gone before you and DON'T repeat the same old stupid accident scenarios.

[c170b53]

This is not meant as a criticism but unfortunately the technology can get ahead of Flt. crews. It could be argued that Pilots need not understand the systems in depth, as failures are infrequent and when they do occur, they can follow the ECAM associated checklist and procedure. I don't know how they could remember all the information required to understand the system relying on memory either. In maintenance we like to think we know it well also but the manufacturers desire to safe guard proprietary information often leads us with just the basic information.
As for the pitot tubes theory, I believe the PHC's associated with pin programming power up faults (spurious faults) and the probes as well but the faults may not last long enough to generate ECAM messages.
ATA SYSTEM : 31
TITLE : INDICATING/RECORDING SYSTEM - FWC - INSTALL NEW FWC K8-1 WITH 386 BASED CPU BOARD ON A330.
MODIFICATION No. : 54786S18181 56069S18891
REASON/DESCRIPTION/OPERATIONAL CONSEQUENCES

AIRBUS has found that Flight Warning Computer (FWC) K8 standard for A330
aircraft is affected by erroneous FWC software pin programs issue identified on A330 aircraft.

Findings are that, each time FWC units are tested on Automatic Test Equipment Complex (ATEC), the software pin programming memory zone is initialized as "all options installed".

As a result the software program pins are correctly re-initialized on aircraft
if the aircraft configuration information is available at the FWC ARINC 429
label input. If this information is not available, the corresponding software
program pins are not re-initialized and the FWC considers the corresponding
options as installed and may trigger erroneous Electronic Centralized Aircraft
Monitoring (ECAM) information to the flight crew.

This Service Bulletin Recommends introducing new software "K8-1" on the two FWCs by means of On Board Replaceable Module (OBRM) replacement or reprogramming or FWCs replacement. This modification will be performed in shop in order to initialize the software pin programming to "0" on ATEC bench.
Accomplishment of this Service Bulletin introduces the following improvements :

— New caution NAV IAS DISCREPANCY is created to detect that the airspeed
indications displayed on captain and first officer Primary Flight Displays
(PFDs) are not in accordance, in order to ask the crew to crosscheck primary
instrument with standby airspeed indicator.

— New cautions A.ICE CAPT+F/O PITOT HEAT, A.ICE CAPT+STBY PITOT
HEAT, A.ICE F/O+STBY PITOT HEAT, A.ICE ALL PITOT HEAT are created
to detect double or triple probe heating failures, to avoid
coherent airspeed drift in icing conditions, by asking the pilot
to switch off one Air Data Reference (ADR).

And also:
NEW PHC PNR 785 620-2 Amdt D INTRODUCTION TFU REF : 30.31.00.023


DESCRIPTION :
Some operators have reported low reliability of the Probe Heat Computer (PHC).

CONSEQUENCES :
The affected operator reported an high rate of ECAM warning are ATA 30-31 R(L) A.ICE
CAPT(F/O) AOA (PITOT,STAT,TAT) HEAT associated with the fault messages invoving the
PHC such as :
- "PHCi(6DAi)"
or
- "AOA SENSORi(3FPi)/PHCi(6DAi)"
- "PITOT PROBEi(9DAi)/PHCi(6DAi)"
- "TAT SENSORi(11FPi)/PHCi(6DAi)"
or
- "AOA SENSORi(3FPi)SPLY/PHCi(6DAi)"
- "PITOT PROBEi(9DAi)SPLY/PHCi(6DAi)"
- "TAT SENSORi(11FPi)SPLY/PHCi(6DAi)"

INVESTIGATION STATUS :
An increasing number of removed PHC were confirmed faulty (70%).
The shop examination allows us to identify that the origin of the failure involved the opto-coupler. This component is in charge of the probe heating supply monitoring.

INTERIM SOLUTION :
N/A

MAINTENANCE ADVICE :
N/A

OPS ADVICE :
N/A

REPERCUSSION ON A/C DISPATCH :
N/A

PERMANENT OR FINAL SOLUTION :
An improved PHC PNR 785-620-2 with Amendment D has been defined and is now
Reply With Quote

And last:
RECURRENT PROBE HEATING SYSTEM ECAM WARNING TFU REF : 30.31.34.013

DESCRIPTION :
Some operators have been affected by intermittent PROBE HEATING SYSTEM FAULTS.

The following ECAM warnings (complete or partial list) are intermittently displayed:
* A. ICE L F/O STAT HEAT
* A. ICE R F/O STAT HEAT
* A. ICE F/O AOA HEAT
* A. ICE F/O TAT HEAT
* A. ICE F/O PITOT HEAT

These warnings are triggered during the flight for a short period of time -a few seconds for the reported cases- and could be linked to specific weather conditions.

In the PFR they are associated with the fault message:
* ATA 303134 Class1 INTERMITTENT PHC2(6DA2)

Notes:
- This phenomenon affects mostly F/O probe heating system (PHC2) fitted with PHC PN 785-620-2 Amdt D. Nevertheless it can also affect the PHC1 (CAPT) and PHC3 (STDBY).

- When the ECAM warnings are displayed for a very short time (less than 1/2s), no
associated fault message will appear in the PFR.

CONSEQUENCES :
N/A

INVESTIGATION STATUS :
- The spurious messages seem to be initiated by a PHC micro processor inadvertent reset. The cockpit effect (ECAM Warning for short period) could be reproduced by simulating short disturbances of the DSO.

- Tests done by the PHC supplier show that a disturbance on the 115VAC supply circuits (TAT,PITOT,AOA) could lead to trigger the above warnings.

- The design of the PHC was reviewed to decrease its sensitivity to disturbances. A PHC prototype designed to clear the spurious ECAM warnings and PHC maintenance messages at ground/flight transition has been successfully tested and evaluated in service. After four months of evaluation on an affected aircraft, the results are fully satisfactory: no spurious message were triggered by the PHC prototype.

- The FWC logics were reviewed (increased confirmation time for PHC inputs), so that
spurious inputs from the PHC will not trigger a cockpit alarm.

Lastly I know the Flt crew know the aircraft handling characteristics better than anyone else, its just too bad mechanics don't fly the jumpseat like we used to, so unfortunately the two groups are drifting apart. Then again if I had a choice between a sweetie or an oiler or sparky I'd probably make the same choice.

[canwhitewolf]

what caused this vertical fin and rudder to come clean off like this?

memories of american 587

[carholme]

I think you will find that the rudder is firmly attached to the vertical stabilizer and maybe, just maybe, the speculation should slow down for a bit.

carholme

[canwhitewolf]

I think you will find that the rudder is firmly attached to the vertical stabilizer and maybe, just maybe, the speculation should slow down for a bit.

carholme

*****************************************************************

Guess i should have said vertical fin and rudder

so was amer587's fin and rudder attached to the fuselage firmly

[carholme]

canwhitewolf;


You are the one who brought up American 587, therefore I would have thought that you gave it some consideration before posting. You probably know full well that the vertical stabilizer from 587 was located with the rudder intact and that one of the contributing causes is assumed to be rudder deflection exceedance caused by manual control inputs.

You began your posts on this accident with the lightening and composite structure theory and have introduced every newspaper article you could find since. Are you now trying to say that the Air France ACARS flag concerning the rudder inputs is common to the two accidents? There is absolutely nothing to support that as yet and eveybody is running amuk with the press stories about the pitot tubes and their relation to the ACARS reports.

Rockie and TTJJ seem to be the only knowledgeable people who have offered any real insight to this point and I am sure they would agree that there is not much that can be interpreted sequentially as yet. There is simply not enough sound information to this point.

So again, I caution against wild assumption as that is all it is at this time.

carholme

[Widow]

It's even hard to resist for the "experts", carholme

New York Times: Telling Debris From Jet is Recovered

[29 ford]

I have never been accused of being smart but I just can't get my head around how anyone thinks this thing would have stalled due to iced up pitot probes. Things may have changed but the last Airbus I had dealings with had a Flight Engineer to hit the pilots if they tried something wrong.

Is a iced over or plugged pitot tube going to give the same result as a leak in a pitot system - Low IAS. If it did wouldn't the pilot advance the power to increase IAS instead of reduce it to put them in a stall condition?

[Moon The Loon]

29 Ford:

That the last time you flew an airplane?

Flight with unreliable airspeed in a modern heavy jet is a [i]very[/i] scary simulator exercise when practised at night in a turbulent environment.

Not one to practise for the first time in real time...

[canwhitewolf]

canwhitewolf;


You are the one who brought up American 587, therefore I would have thought that you gave it some consideration before posting. You probably know full well that the vertical stabilizer from 587 was located with the rudder intact and that one of the contributing causes is assumed to be rudder deflection exceedance caused by manual control inputs.

You began your posts on this accident with the lightening and composite structure theory and have introduced every newspaper article you could find since. Are you now trying to say that the Air France ACARS flag concerning the rudder inputs is common to the two accidents? There is absolutely nothing to support that as yet and eveybody is running amuk with the press stories about the pitot tubes and their relation to the ACARS reports.

Rockie and TTJJ seem to be the only knowledgeable people who have offered any real insight to this point and I am sure they would agree that there is not much that can be interpreted sequentially as yet. There is simply not enough sound information to this point.

So again, I caution against wild assumption as that is all it is at this time.

carholme

*******************************************************************

well certainly I dont need you to caution me about what to write about, im sure you can understand that, its called freedom of expression and freedom of thought

you state
quote
You probably know full well that the vertical stabilizer from 587 was located with the rudder intact
unquote

the report about american 587 also says this...
quote
"the two pilots in the cockpit were in all likelihood unaware that they were now part of a previously unheard of scenario: the complete separation of a transport aircraft's vertical tail fin during normal flight.
unquote

(well rudder intact to vertical fin is a different phrase than fin and rudder displaced or torn from the plane in flight from whatever cause)

you also state quote:
Are you now trying to say that the Air France ACARS flag concerning the rudder inputs is common to the two accidents? There is absolutely nothing to support that as yet and eveybody is running amuk with the press stories about the pitot tubes and their relation to the ACARS reports.
unquote:

show me where I said thats the present acars are common to the two accidents! I never said that anywhere that i can find, and ive never even mentioned a pitot tube at all

Rockie and TTJJ have presented views and thats fine and appreciated - but does that mean that no one else should contribute to this forum? because if thats the case the rest of us may as well go home and let them have the whole blog to themselves which i dont think these two would agree with anyway. we all have different experience levels in flight through the years

why not raise your own theories or facts instead of sitting there trying to tear apart some else's views and thoughts

why this tail is found like this and totally seperated from the plane in this manner is of interest,

(and in addtion may help in determining the general area of the black boxes as well perhaps)

[canwhitewolf]

Investigators recover 29 bodies in total

http://www.telegraph.co.uk/news/worldne ... total.html

Mr Waldock - who examined the photos and video of the stabiliser and rudder - said the damage he saw looks like a lateral fracture.

"That would reinforce the idea that the plane broke up in flight," he said. "If it hits intact, everything shatters in tiny pieces."

No signs of burn marks on the stabiliser offered scant clues: Any explosion or fire in the fuselage would likely not make its way back to the tail section, according to Mr Waldock. Examining the fracture surfaces will also be key, he said, since it will indicate from what direction the force came that snapped the piece.

Peter Goelz, a former managing director of the National Transportation Safety Board, said the faulty airspeed readings and the fact the vertical stabiliser was sheared from the jet could be related.
etc