AF447

[PJ2]

UTC....W/P........Lat.........Long.........True.........Mag.......NM. .......GS
0133...INTOL.....1 21.7S...32 49.9W..027.9.......045.7.....182.2....540KTS
0153...EPODE....1 19.4N...31 24.7W..027.9.......045.7.......62.7....540KTS
0200...ORARO...2 14.8N...30 55.4W..022.3.......040.1.......86.4....300KTS
0214...Final.......3 34.7N...30 22.5W

Interesting groundspeed at ORARO, if true.

[grizzled]

wiggy . . .

wfd is correct; the primary purpose of ADS B is to aquire and use transponder data regardless of ground-based radar interrogation. ADS B also provides some additional benefit in a (secondary) radar environment. A transponder can indeed be interrogated by a satellite and that is exactly what happens with ADS B.

[mm43]

http://countjustonce.com/af447.jpg

Probably better laid out as per this screen shot.

As I said earlier the GS reported at INTOL was 543KTS and 540 has been used through to ORARO, though likely was reduced at EPODE on encountering turbulence. How this compares with the actuals, only time will tell.

mm43

[avspook]

Usually crew initiated AP disconnect is not reported either by ACARS or on the PFR
The message is generated by an unusual AP disconnect either by the AP sys (Auto) or by the Crew using the FCU (Non-Normal Method)

The message is present to alert maintenance that perhaps the crews sidestick disconnects are not functional & they needed another (manual) method of AP disconnect or that the AP disconnected for a variety of reasons

[Captain-Crunch]

[/URL]A wiki-type format - where the information is more of a living document - would have strengths in a case like this (after all, the "real" investigators use report drafts, not emails back and forth, to arrive at a final agree and reviewed version...)


Hey PJ2, others: Mad (flt) Scientist is right. A great tool so that Our "discoveries" or our "consensus" may be preserved for others on a summary page is to start a wikipedia page. Somebody has already done that. We may add or delete portions we do not like.

Sorry if somebody has already pointed that out.... I'm still 2 pages behind! :E

I have corrected the part of it that claimed electrical problems, since nothing yet shows failures of buses. If you're not familiar with Wikipedia pm me, and I'll walk you through how to change it.

Cheers

CC

Click here:

Air France Flight 447 - Wikipedia, the free encyclopedia (http://en.wikipedia.org/wiki/Air_France_Flight_447)



.

[grizzled]

mm43:
Sorry, it's late and these AF threads have become long (and sometimes tedious) so I may have missed something. I'm wondering about the "ACARS" position information you refer to: "0214 Final 3 34.7N 30 22.5W".

On the screen shots I've seen so far, position information was not displayed, so where specifically did your lat/long info originate?

[982500h]

MR8: "It is Airbus procedure to check the WX radar return on taxi out when switching on the WX radar....For TO the WX radar is set up at about 5 degrees and adjusted during climb."

This is for an analog radar. The new Honeywell RDR-4000 (option on A330) shouldn't require this. Can anyone post what model of WX Radar was on the AF447? If possible, post the source. I fly with a similar radar and I'm concerned with its accuracy at times.

[avspook]

Pitch is availabe From the internal Fibre Optic Gyro (FOG) internal to the ISIS
The ISIS msg is not telling me the unit had a total failure . Perhaps Airdata inputs only

[Airbubba]

I don't know how often ADS squirts it's reports out.

The Enhanced Squitter function on an ADS-B aircraft seems to send out a position message every second or so from my observation with personal receiving equipment. This is a passive function, does not need to be 'interrogated' as with mode 3. I believe ADS-C (or ADS-A) generates position reports less often but sends them through the satcomm link.

Maybe Shore Guy is still lurking here, he has worked for years to bring ADS-B online and we all owe him for his efforts to make us safer.

If the wreckage is never found, the stream of messages on ACARS, HF, and ADS-B and/or ADS-C may well be our best hope of understanding this mishap.

Since ADS-B transmits at 1090 MHz and is line of sight the only record of AF447's final minutes may come from a surveillance aircraft or satellite which might be a long shot. When Delta had a near miss out over the Atlantic in 1987 recordings from at least two military aircraft helped sort out the aftermath at the hearing.

[vapilot2004]

Probe heat (static, pitot) are powered by:
28V DC Bus 1 & 2
Essential AC bus (1)
Main AC bus 2
Emerg AC bus (via inverter)
Therefore one or more heaters are always powered even in emerg elec config.

ADIRU's

#1 & 2 are located together in rear AV bay
#3 is off to the side but in the
same AV bay below the cockpit floor.

The Air Data Modules are located
more forward of the ADIRU's in the
AV bay. #1 & 3 are on the left
side while #2 is on the FO's side.


Cabin Press controllers:

Report ADIRU data failure
ADIRU Data to the press controllers:
TAT, Mach and Static pressure

The descent rate warning as mentioned previously is for rapid aircraft descent where the cabin altitude will catch the aircraft altitude.


I was also given a run down on the mechanics of the standby
flight instruments, altimeter, airspeed and artificial horizon.

It seems that the airspeed and altimeter are piped to the air sources: no ADIRU needed and the standby artificial horizon is a gyro. This does not jive with some of the comments regarding loss of all three ADIRU's and the crew being 'in the dark' unless all of the ports were iced over and only attitude was available via the gyro.

Can someone shed some light on the above observation? Could it be that newer build aircraft have placed these old-timer gauges on the same train that the dodo bird rode out on?

[avspook]

The ADIRU are compartmentalized to be fault tolerant
The message describing an Air Data ADIRU failure is different from An RLG Ring laser Gyro failure, The failure of Air data either input or calculation does not preclude the Inertial portion of the ADIRU from giving correct attitude data

[Final 3 Greens]

PJ2

I am a PPL/airline pax, so please treat this comment as an uninformed question, from someone with no relevant aviation knowledge, being upfront about that.

If the groundspeed at ORARO is true, due you think there is any possibility could have been tornadic activity?

I remember well the F28 that encountered a tornado in the Netherlands and broke up middair.

Please don't be irriated if the met info or other reasons make this unlikley/impossible, my only interest in this is as a frequent passenger on this a/c type and whether this accident was a 'one off.' I am not passing an opinion, just asking a question.

Perhaps we will never know.

[Alwaysairbus]

I apologise if someone has already mentioned this but it's a struggle keeping up withall the posts...
I read somewhere on the net of an Airbus bulletin a few years back about possible air data inaccuracies in the case of radome failure. Can anyone shed any light on this?

If bad weather / lightning strike was a possible cause and it did take a exceptional strike on the radome leading its structural failure, then with the disturbed airflow to the pitot probes/adm's that might have caused the inaccuracies, plus no weather radar and at that altitude and speed debris might well of gone down both engines leading to not only unreliable air data indications but also engine thrust problems / failure leading to electrical power tripping off.

In this day and age of GPS, ACARS, satelite monitoring and IT, i really do hope that the investigators find the FDR/CVR and do get to the bottom of this as there may be implications to operation of all aircraft types through out the world.

[weatherdude]

Tornadic activity will not be seen at that altitude, anyway over water we would talk about waterspouts and with the water temperatures we can't completely exclude the presence of a waterspout in these highly active zones, but a waterspout will very, very, likely not have been the cause for whatever happened in the sky as long as we happen to believe that the accident took place at FL300+.

[Jetjock330]

On the A332 we had the ISIS fail on shut down of both engines on ground, as soon at the NBPT (no break power transfer) kicked in from the APU generator.

Ping went the C/B of the ISIS on the ECAM.

Outstation engineer was unable to repair and dispatched us according to MEL back to base. After getting the gear up on departure, we had another ping on the ECAM, ISIS standby battery C/B popped and so we continued back to to base.

More than enough engineers to receive the aircraft with new parts in hand.

I had never seen this before, but the ISIS was a dead duck in under a second!

[PJ2]

Final 3 Greens - I think weatherdude answered your question really well.

The "300kt" groundspeed value could be explained by the degradation of either the aircraft or the aircraft systems/sensors but we can't say.

[fcom]

Quite simply the A/C encountered Severe turbulence causing the autopilot to disconnect, normal procedure is to disconnect the autothrust and fly the aircraft manually.

There is a strong probability that the aircraft suffered a bombardment of hailstones if the severity of the CB's reported in the area are anything to go by which could cause engine failure.

This would account for the loss of the electrical system and eventual loss of cabin pressure as indicated by the ACARS messages sent.

With the amount of static in the area a mayday call on HF would be useless but to be honest with everything going on and severe vibration I doubt whether you could find the button.

With only backup for flight controls i.e manual rudder control and pitch trim, stabilised flight or recovery would be almost impossible with structual failure almost inevitable.

[Starbear]

I think it was the AeroPeru B752 accident in '96 that led to Boeing introducing the Unreliable Airspeed Memory Items & checklist (the checklist already existed when I did my initial back in 2004)

Sorry, perhaps I should have made it clearer. Boeing did not provide unreliable airspeed QRH specifically for B777 before the Malaysian upset (2005). They deemed the ADIRU set up so sophisticated that unreliable airspeed could not occur. B777 upset report (http://www.atsb.gov.au/publications/investigation_reports/2005/AAIR/pdf/aair200503722_001.pdf)

You are probably correct for the B757/B767 and the older generation of aircraft.

[greenspinner]

ISIS on this case doesn't fail , just reporting bad input.
The fact you quote is that ISIS need a reset after a quite long operating, but now it's over, we don't have to reset ISIS CB after that time.
from my own, and as the data I've got message related to ISIS means no data from Stby probes ....

[A330AV8R]

1) In the event of an ADR 1+2+3 Fault or any combination therin , they would have got only a single chime master caution(amber) , if it was an Overspeed warning VMO + 4 KTS OR MMO +.006 They would have got a Master Warning CRC(RED) , however in either case there would have been ECAM actions to perform and in the 1st case there would be certainly some AIR DATA switching involved , as you might have already guessed there is a LOT of redundancy built in , so I do not believe that faulty speed crap for a minute .

2) In a 3 Crew operation as is always the case the relief guy would have been resting during this mishap , and unless there was a SIGNIFICANT flight upset and or if the guys upfront called for him he would not have been on deck at that point .

3) As I mentioned in the previous thread this was more than one or an isolated event that brought it down

[HEATHROW DIRECTOR]

<<With the amount of static in the area a mayday call on HF would be useless >>

Static interference may well have caused bad intereference to the aircraft receiver, but surely pilots are trained to transmit "blind" in an emergency? An HF transmission could have been heard thousands of miles away where interference might have been minimal.

[Epsilon minus]

Multiple causal factors?
Weather
ADIRU failure. Note the nose pitch down with the Qantas incident.
MEDIA RELEASE : 14 October 2008 - Qantas Airbus A330 accident Media Conference (http://www.atsb.gov.au/newsroom/2008/release/2008_43.aspx)

[concordino]

Being an Airbus Pilot myself, i feel very bad for the pilots of AF447.

It is highly probable the crew found themselves in a very furious and complex situation with not enough time to analyze and react properly.

Speaking from own experience, most pilot abilities are significantly reduced in moments of severe turbulence and violent shaking as well as heavy percipitation hampering the fuselage/ cockpit windows.

I realy hope the CVR/FDR are recovered, we all stand to learn a great deal from this tragedy.

Without wanting this to divert into an Airbus conception philosophy debate:*.

Given the protections/stabilities available in normal law being lost in so little time and all the redundancies possibly failing. Maybe It is time for Airbus to reconsider the fact that when redundancies are lost, only then, Pilots will be in dire need for protections to kick in.

My humble little contribution.

[Airbus Unplugged]

(Not a 330 man but) If they'd had a serious electrical failure, possibly with both AC busses off, HF would be lost, and possibly the weather radar. They may well have blundered into a cell whilst distracted with a major procedure.:rolleyes:

[milsabords]

Hi,

Right now, a BEA press conference is broadcast on France 24 TV channel.
I'm in no way competent in such mattters. If skilled members of this forum could watch it they might gather useful info.

Cheers

[vapilot2004]

ISIS on this case doesn't fail , just reporting bad input.
The fact you quote is that ISIS need a reset after a quite long operating, but now it's over, we don't have to reset ISIS CB after that time.
from my own, and as the data I've got message related to ISIS means no data from Stby probes ....

Greenspinner, you appear to have a keen understanding of the latest builds of the A330's. Let me ask you this: Does the newer ISIS system have it's own pitot & static pressure transducers or is this supplied by one of the three ADR units?

Also, please tell me that the 'ISIS' artificial horizon is indeed a gyro?

[Jimmy Do Little]

2) In a 3 Crew operation as is always the case the relief guy would have been resting during this mishap

I feel differently about this. Do you have some information to substantiate this? The AF SOP for example. Otherwise, I would tend to believe that the "Relief Pilot" would probably be in a pilot seat during this time on a flight of this duration.

[Jimmy Do Little]

Maybe It is time for Airbus to reconsider the fact that when redundancies are lost, only then, Pilots will be in dire need for protections to kick in.
Interesting, and quite true. Especially these days when we're seeing lessor levels of general flying experience in the airplanes then we did in years past.

[greenspinner]

From the AMM, I never create nothing, but I know how to use it !!!
ISIS Indicator

The ISIS indicator is supplied with 28VDC from:
-
the ESS BUS (403PP) first, (when the aircraft electrical network is energized)


-
and the HOT BUS (701PP), when the speed detected by the ADIRUs 1 and/or 3 is more than 50Kts.

In case of loss of the ESS BUS, the ISIS indicator is supplied only from the HOT BUS (701PP) through the ESS BUS SPLY GND/FLT COND relay (7PC).

Consumption of the equipment is 20 W maximum.

Transparency time for the ISIS indicator is not less than 50 ms (memorizing of current configuration on power supply transients comprised between 50 and 200 ms).

The display is lost during power supply cutoff comprised between 50 and 200 ms.



Thought, ISIS never failed,is just reported conditiond & situation after an unthinkable event........

[avspook]

vapilot2004
Quote
Let me ask you this: Does the newer ISIS system have it's own pitot & static pressure transducers or is this supplied by one of the three ADR units?

Also, please tell me that the 'ISIS' artificial horizon is indeed a gyro?

Yes ISIS has a separate Input independent of ADIRU & Yes it has its own internal Fibre Optic Gyro (FOG)

[TwoOneFour]

France 24, with great timing, cut off its coverage of the conference just before getting to stuff about the aircraft itself. Merde. :ugh:

[pool]

Maybe It is time for Airbus to reconsider the fact that when redundancies are lost, only then, Pilots will be in dire need for protections to kick in

Please NO!
Redundancies are here to exclude failures. Protections must be able to differentiate good from bad, thus rely on redundancies!!!!!
Don't forget: One redundancy is the pilot. If you want some higher up protection to set in when some technical redundancy fails, you would effectively take the pilot out of the eqation. This happened with the QF flight, as the failed ADIRU told the aircraft to be too high and ordered descent, the pilots realised this was wrong, switched off the AP and wanted to pull just to have the holy FBW to deny this input!
For such cases the new instructions by Airbus now instructs pilots to go by a AIC circular checklist and start to disable some computers with switches on the overhead panel. This is finally realising that only a non FBW partner in redundancies can remedy the situation. All this during a highly surprising and unexpected manoever. Not enirely realistic any pilot would admit.
Now some people are shouting for even more, new protections when the initial ones fail.

All this recalls in me Goethe's Sorcerer's Apprentice when he finally concludes:

"From the spirits that I called Sir, deliver me!"

[MPH]

Just out of intrest what´s the recomended turbulence penetration speed for the A3330? Is it 280/300 or....?

[johangad]

One is resting, two are in pilot's seats. Where is the resting guy according to AF sop? Is the rest compartment just behind the flight deck or in the "cellar" in the middle of the aircraft? There are different solutions as you know. And then the possibilities to reach flight deck in an emergency are different I would say.
(60+ Captain, now on MD80 but b4 on A330/340)

[agusaleale]

Una hipótesis a tener en cuenta (esta sí) (http://www.aeroclubdetoledo.com/content/index.php/component/content/article/20-aviacion-comercial/44-airbus-330-air-france)
Written by Pedro Guil
Thursday 04 June 2009 20:01

Hello Colleagues, I have a theory regarding the malignant potential cause of the crash of Air France's Airbus, and is based on my own experience. The meteorological phenomenon happened to me in the area where the plane crashed on May 9, 2001, when we returned from Buenos Aires with a B-747-300 TF-ATH enrollment, Air Atlanta flight for Iberia at that time. Since we overflight from Rio de Janeiro, still exactly the same route as the AF447 and passing through the area around the accident while crossing the ITFZ at FL-370, with a moderate to strong turbulence, in a matter of 1 to 2 minutes of flight, we experienced a sudden rise in outside temperature from -48 º C to -19 º C. As a result of this rise in temperature, we turn out to fly with a margin of 10,000 kg, to became 15,000 kg away from standards to that level flight, and with immediate initiation of an aircraft loss, with strong vibrations. We disconnected the autopilot and went down, losing 4000ft, founding us in the "coffin corner" meaning this that the plane was giving "loss" for high and low speed, and If we have not disconnected the autopilot and went down, perhaps today we would be in the bottom of the ocean making company to Air France´s plane; the autopilot would have tried to maintain altitude incrementing the power of the engines .... and that´d been impossible, and perhaps we would have entered into an abnormal position very difficult to recover because of the night and the spatial disorientation beeing into clouds.
Lately, I've been flying until February 2009 the A-340 and the "crisis" sent me to "dry dock"; having made lots of times the same route, Rio - Madrid I have not been back to this exceptional meteorological circumstance in 40 years working as airline pilot, it only happened once. I would describe as a huge funnel with a diameter of 40 nautical miles of extremely hot air and as a result of a forming CB or something similar, ascending to great heights, affecting us and after about 5 minutes flying with the "tight ass" it began again to normalize backing the temperature back -48 º C and then being able to rise again to FL-370.
According to the Airbus approach, flying in severe turbulence or strong, you do not disconnect the autopilot, but what is not expected it this kind of phenomenon that comes to my mind ... and if they didn´t disconnect the AP for not noticing this phenomenon (if it happened) in my humble opinion they may have been into abnormal positions and the plane may have been broken, this theory supports the order of messages ACARS (which are automated messages sent by the plane via satellite without intervenction of the pilots) received.

[BOAC]

Taking a deep breath, I ask if we can possibly summarise what is known or can be REASONABLY deduced out of all this dross? I do, however, feel that we can rule NOTHING out at this stage:-

1) Is it safe to assume that the apparent sequential system 'failures' were triggered by the weather conditions in the area?

2) Is it safe to assume that standby attitude would probably still be available? (difficult to determine above!)

3) Is it safe to assume that engine control would be unlikely to be compromised by the known 'failures'?

4) Is the reported 'inability' of the AB 330 probe system to cope with 'heavy' icing a fact, or just more of the rubbish here? If known, was there any qualification to the release to service (icing) and if not, why not?

5) Has anyone yet established what MEL items were extant?


I'm not sure how many pilots here have actually experienced 'severe' turbulence in an airliner. I have, once, and I was scared (and I do not scare easily). If we interpret the 'hard' turbulence report as meaning severe, I pity that crew. Throw in system 'failures' and it is a one-way street in my opinion. In my experience, we had to make an emergency descent to avoid loss of control (737 with ALL systems working), and I can assure all that it can be extremely difficult even to think rationally in that situation. I was waiting for 'something to break', and needed the Boeing 'yoke' to hang on to, and I do wonder how you cope with a tiny sidestick? Can you avoid involuntary inputs while being tossed around?

Moving on, NB away from facts:

I would expect (my supposition only) that the crew were left with no option but to make a descending turn-back. That there was apparently no call (heard) to advise other traffic (iaw oceanic procedures) I find surprising as it is a fairly high priority matter, more-so than position reports. Assuming they were operating IAW SOPs therefore I suspect they were already out of control at this point.

[greenspinner]

I will not speculating,
but from now with all the concrete fact we have, A/C being in a severe Icing condition, leading to a loss of many parameters
with the full parameters I’ve got now, it is clear for me that A/C condition was out of normal condition
I’m surely an engineer specialist, with quite a good and long experience on this A/C, but rationally, I still can.t explain this !!!!!!!!!!!!!

[Me Myself]

I still can.t explain this !!!!!!!!!!!!!

Try Pitot Probe freezes, starts a hoodle of alarms like ADR's from 1 to 3. ISIS breaks down. Fly the plane in the middle of a storm (Air France 447 - AFR447 - A detailed meteorological analysis - Satellite and weather data (http://www.weathergraphics.com/tim/af447/) ) on alternate law with no attitude and speed information.........this should get you started.

[Runway 31]

From the BBC website

The Air France jet which went missing over the Atlantic sent 24 error messages before it is believed to have crashed, French investigators say.

The messages came as the plane's systems broke down one by one, said Alain Bouillard, head of France's aviation accident investigation bureau.

French weather experts said there was no evidence the plane, carrying 228 people, hit an "exceptional" storm.

The Airbus A330 vanished en-route from Rio de Janeiro to Paris on Monday.

[Captain-Crunch]

Guys,

When reading the acars reports the type (typ) message is important. Keep in mind the chicken and the egg: Faults frequently cascade into Warnings. (FLR=Fault Report) (WRN = Warning) In the code block: Faults are six digit (FR). Warnings only four usable (WN).


greenspinner wrote:
ISIS reset
ISIS on this case doesn't fail , just reporting bad input.
The fact you quote is that ISIS need a reset after a quite long operating, but now it's over, we don't have to reset ISIS CB after that time.
from my own, and as the data I've got message related to ISIS means no data from Stby probes ....

Maybe this is very significant Greenspinner. Are you thinking that the fault 3422 ISIS at 0211z is an Lack of Input Data From the Standby Probes?

This could lead credence to the theory that ALL probes and pitots iced up meaning: there was nothing left to switch to, and nothing left to fly on pitot static wise (a/s, alt, v/s). This would explain why all three Air Data computers gave up, and why the rudder limiter gave up, and why a cascade of warnings hit the crew.

I'm going to speculate, that a jet upset into thicker air that's recoverable, occurs in roughly 60 seconds. Any takers? I base this on an actual emergency decent we did in a 747 from FL430 with the gear down/boards up and decent at .86M?/320kts. We think we exceeded 10,000/min. The Capt was an Edwards Test pilot. What happens is you get into a test pilot world where a phenomenon known as "dynamic spillage" occurs. At this speed, and with engines at idle, most of the relative wind can no longer pass through the engines. It instead bounces out off the N1 fan, back around the outside of the engine cowl. It creates a pronounced shutter/buffet from the engines wagging back and forth on the pylon. It is a violent maneuver and nothing like the simulator. At the stand, I spent ten minutes trying to pick my pencils pens and flight bag contents out from behind the copilots rudder peddles.

But for any FAA guys reading this: This is a fictional story for educational purposes only. :oh:

So Theoretically,
If they iced up at 0210z..... they flew for another three minutes before the really unlucky event hit them at 0213z: the loss of full flight controls.

We know now, from our techs here at Pprune, that the last acars transmission (0214z) was a #2131 Advisory WARNING: Cabin Rate Change. This does not mean depressurization. It is a warning that at your current rate of aircraft descent, that you will "catch" the cabin too early (before you land) and this will hurt your ears dearly. The remedy on normal ops is to manually select the pressurization rate knob to a greater cabin-descent rate position. Translation: At 0214z they were already in the high dive.

Opinions? (from jet pilots, mechs..)

Now Spinner, what, precisely, do you feel is a 22-83-34 flt cntrl fault?

CC

[woodpecker]

Greenspinner,

Thanks for your input, being a Boeing man I could not see that Airbus would have any other power supply for the ISIS than from the hot battery bus, so of all the ACARS transmitted messages the one relating to the ISIS grabbed my attention.

It is very easy (Boeing and Airbus) to, during the conversion ground-school, simplify the various systems under the " need to know" banner.

With regard to standby horizons (as we all used to call them) it amazed me during my 777 conversion, that technology had coaxed a laser to spin and act as a gyro (the way the Boeing SAARU was described), or as avspook describes the ISIS has an internal Fibre Optic Gyro (FOG) with no moving parts.

Concentrating on standby attitude indication (putting aside the other data that the ISIS provides to the crew), as long as there is battery power these "gyro's" should continue to proved basic standby indications of attitude.

What the Boeing course didn't cover was did the SAARU (and ISIS in the case of an Airbus) being unlike the old horizon with gimbals have any "limits" in roll and pitch, beyond which the internal checking would have suggested a fault and generated a maintenance message? If not, in the case of the ISIS, could the message have been generated by "erroneous" airspeed data being circulated within the ISIS, with the crew still having a downgraded ISIS still providing basis attitude indication to the crew?

Only Airbus can answer these questions, rather than us, as professional pilots on this forum, who have only been subjected the the "need to know" brainwashing technical courses!

What the communications from Airbus , Air France and the investigators yesterday led us to believe is that they have (perhaps), even without the flight recorders found, a common thread that could have produced so many pieces of electronic equipment having been downgraded/failed... unreliable airspeed.

Lets hope they find the recorders...

[Jimmy Do Little]

...If we interpret the 'hard' turbulence report as meaning severe...
Here lays one of the problems. Too many people are inaccuratly reporting turbulance levels, which in-turn becomes the baseline for someones experience level.

When people report a few bumps (2 - 5 knots of airspeed change and no vertical changes as Moderate or Sever turbulance, the inexperienced pilots hearing this, and THEN experiencing THAT turbulance are lead into a false sense of what Moderate or Severe really means.

Then, when a prog report indicates "...Mod to Sev turb associated...", etc, they don't really understand what that will mean should they decide to blunder through that weather system.

According to a NASA document I read several years ago, you are experiencing severe turbulance when your aircraft is experiencing a GREATER then 25 KIAS airspeed change and close to a 2000 foot per minute IVSI change.

Keep this in mind that next time you see weather that CAN cause Sever turbulance. And also, when you report it.

[stickyb]

The position that has been quoted and associated with the final ACARS has come from somewhere. Would seem that the ACARS was on SAT and the position was also transmitted at the same time.

UN873
UTC W/P Lat Long True Mag NM GS
0133 INTOL 1 21.7S 32 49.9W
027.9 045.7 182.2 540KTS
0153 EPODE 1 19.4N 31 24.7W
027.9 045.7 62.7 540KTS
0200 ORARO 2 14.8N 30 55.4W
022.3 040.1 86.4 300KTS
0214 Final 3 34.7N 30 22.5W

The 0214z report places the a/c 8.5NM left of track, and the GS noted are relative for the times and distances run, though at what point track and speed deviations were actually made is unknown.

Peak CB activity has been determined at 0200z (ORARO) though the edges of the CB cells were well beyond that position.

mm43

I cannot understand how this information (if it is correct) has "just appeared". Surely somebody somewhere must have known about it from the start, and should have made it available to the SAR effort at least.

Does anyone know how the final position ties in with the current SAR location?

(And yes, I do realise that "final position" is where the last report came from, not necessarily where the point of impact was. but around about that location must be a good starting point)

[Junkers388L]

First of all, my sincere respect for the knowledgeable discussion on here - extremely enlightening and informative, thank you very much!

After going through the posts, I have been musing about the ACARS message regarding TCAS (3443005) transmitted at 02:10. Can anything more specific than a TCAS fault be inferred from this code?

Generally, since it relies on ADIRU input for ownship pressure altitude (looped through the Mode S transponder according to the A320 AOM I have at hand, 1.34.80 P3, REV 23), I would expect TCAS to degrade, at minimum, to TA only level upon ADIRU failure.

Therefore - please correct me if I am mistaken - I think the TCAS error might be regarded as further indication for inconsistent/erroneous/unavailable air data sensor input - unless somebody can validate the claim by avherald.com that it relates to the TCAS antenna.

Regarding ADS-B, it is indeed intended, among others, for enhanced surveillance in non-radar airspace.
The implementation via 1090 MHz extended squitter (DF = 17) allows the transmission of, among others, Airborne Position Messages (~2 per second), Airborne Velocity Messages (~2/s) and Identification Messages (~1/5 s). This will give anyone interested in receiving the data the F-PLN callsign and flight state information within a range of, IIRC, ~ 200 nm.

Since the airframe was fairly new, I would expect from personal observation of more recently delivered Airbus aircraft that it was already equipped with ADS-B out. However, there was probably no-one within range to receive the data.

Chris

[dieana]

I´m wondering why the pilots didn´t make a distress signals for ex "may day", if you have at least 5 seconds you will, and if you have entire electrical loss you will still have the battery with vhf 1. Besides I don´t know why the 3 ELT didn´t work, they start to work with an impact or with a number of g´s force.

[kbootb]

There was much talk in the press of a manually entered ACARS entry regarding entering CB.

Is there any independant evidence of this transmission other than it being in the press?

No agenda behind the question, I'm simply separating press speculation and interpretation from the factual evidence, such that it is.

[dicksorchard]

PITOT TUBES


JUST SEEN THIS - IT COULD BE OF INTEREST TO YOU GUYS AND THIS THREAD .


Air France orders vital components replaced on jets - World news, News - Belfasttelegraph.co.uk (http://www.belfasttelegraph.co.uk/news/world-news/air-france-orders-vital-components-replaced-on-jets-14329308.html)

[Kalium Chloride]

From the BEA briefing this morning:

Investigators: Missing A330's ACARS sent 24 error messages (http://www.flightglobal.com/articles/2009/06/06/327532/investigators-missing-a330s-acars-sent-24-error-messages.html)

[pappabagge]

I think it's worth putting some sort of perspective into the logical next step of the operation: that of locating the wreck and the FDR & CVR.
We don't have to go further back in time than a dark eastern Canadian night in early September 1998...

SWR111 impacted intact at 20° AND, ~110° right bank at 350kts: a ‘steep water entry’. At impact Eng 1 was producing ‘high power’, No 2 was windmilling following shutdown in flt and No 3 producing slightly more than flt idle.

Although it impacted at speed, the acft was not in freefall thus terminal velocity had not been achieved and the acft did not break up prior to hitting the water.

All souls perished instantly from the deceleration (350g) and only fragments of human remains were recovered, to be identified by dental records and/or DNA.

A seismic event was recorded by a land station. The wreck came to rest a few miles offshore at a depth of 55m. The resultant ‘relatively compact’ debris field measured 125 x 95m. The terrain was undulating, silted and at bottom around 1m visibility. The accident occurred on 2nd Sep 98, with the FDR recovery on 6th Sep and the CVR on 11th Sep. From 'only' 55m. The FDR/CVR situation was compounded by their respective ULB broadcasting on the same frequency, frustrating efforts to pinpoint their origin, and in a state of becoming detached from either recorder. Jet-A fuel was apparent on the surface for a few hours prior to evaporating.

Transpose this scenario with the aid of the few known factors thus far in the AFR447 case, and it is fairly obvious that if we, for the sake of simplicity, take the depth of the Atlantic in the general region of the point of impact as 5500m (10 times the depth of SWR111 and hundreds of miles from land), then the debris field would be of the order of 13 x 10 kilometres.

This, in mountainous terrain, with the valleys mainly filled with pooling mud.

And that’s assuming that the acft impacted in one piece.

If it had reached terminal velocity (rough calcs according to Stoke’s Law would put the plunge at around 400~500kts depending on superstructure presentation relative to the surface) and consequently broken up on its way down, just multiply the debris field projections by the number of impact points, and compare that with the scale and effort that went into the SWR11 recovery and you’ll quickly appreciate why the French are already hedging their bets and warning that the FDR & CVR may well never be found.

The apparent lack of any appropriable seismographic event may conceivably be due to a large number of fragments impacting at different velocities, at different locations and slightly different times.

This, however, runs diametrically contrary to the hitherto lack of flotsam and jetsam on the surface. More break-up prior to impact would presumably imply more lighter debris, spread over a significant area.

In summary the rule of thumb in this contributor’s humble opinion would be that the ‘needle-in-the-haystack’ operation – on paper – would command the effort of the recovery of SWR111 raised to the power of ten. At a conservative estimate.

How far do you go? How far would you need to?

Sincerely,



PB (one who lost two colleagues in the pointy end of SWR111)

[Swedish Steve]

This would explain why all three Air Data computers gave up,

What makes you think that all three AD computors gave up?
In all the messages there is only one referring to the AD.
ADR Disagree. This infers that there is a fault with one AD output. How do you get to all three?

p.s. glad you said AD computors. Many posters here refer to ADIRU failures but it is only the AD part of the ADIRU that has failed, not the IRU part.

[HarryMann]

I was waiting for 'something to break', and needed the Boeing 'yoke' to hang on to, and I do wonder how you cope with a tiny sidestick? Can you avoid involuntary inputs while being tossed around?

I doubt it somehow, anyone tried driving a 4x4 off-road with a joystick? Impossible I'd say, a proper steering wheel stabilises inputs and allows the torso to give a 'sensible' reference frame...

[lear60fellow]

I just read in this Spanish forum ( Una hipótesis a tener en cuenta (esta sí) (http://www.aeroclubdetoledo.com/content/index.php/component/content/article/20-aviacion-comercial/44-airbus-330-air-france)) a theory based on an actual situation that happened to an IBERIA flight on May 2001, the actual captain was flying B747 and retired flying A340, it´s quite interesting as it happened in the same area. I will translate the basics.

"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. The consecuences were that we passed flying with a margin of 10.000kgs to being 15.000kgs above maximum weight and out of limits at that temperature and Flight Level. Inmediately the aircraft experienced a stall situation with lots of buffering. I desconected the AP y and we descended 4.000ft flying in the coffin corner having at the same time high and low speed stalls. If I wouldn´t have disconnected the AP and flew it manually we would be now into the deep ocean. The AP tried to maintain at all times the altitud using engines and that was impossible and the consecuences would have been an abnormal position of the aircraft and spacial desorientation to recover it at night and into the clouds.

I would describe it as an enormous 40 miles radius of hot air on the begining of a developing storm ascending to high altitude. After 5 min everything became normal and we continued our flight.

AIRBUS criteria says that flying into moderate or heavy turbulence "YOU MUST NOT DISCONET THE AP" but the fenomenom is not described or even contemplated and if the crew of AF474 did not disconneted the AP probably they had a situation similar to the one I experienced. The theory is that ACARS messages were sent due to this situation:


” New information provided by sources within Air France suggests, that the ACARS messages of system failures started to arrive at 02:10Z indicating, that the autopilot had disengaged and the fly by wire system had changed to alternate law. Between 02:11Z and 02:13Z a flurry of messages regarding ADIRU and ISIS faults arrived, at 02:13Z PRIM 1 and SEC 1 faults were indicated, at 02:14Z the last message received was an advisory regarding cabin vertical speed. That sequence of messages could not be independently verified.”

On basics it means: the AP disconnects when gets to the limit but the aircraft is already on an abnormal position, then is reverts to alternative flight control, then is followed by ISIS and Interial failures, then PRIM1 + SEC1 computer failures and finally a sudden decreas in cabin pressure (when the aircraft is already divided in parts), multimple electronics failures as the aircraft is desintegrating.

All this happens between 2:10Z and 2:14Z

[avspook]

woodpecker

WRT the SAARU on the 777, this was a mandated device the FAA made them installl as they did not trust honywells 1 in 3 billion chance of an undetected ADIRU failure.
Its input is AVERAGED with the ADIRU .. if the SAARU had been on MEL the Malasian 777 would have attempted to fly backwards,

SAARU was a cheap device using teh same FOG type RLG's as the ISFD (Boeing for ISIS) consequently they failed a lot.
New SAARUS have the SAME RLG's as the ADRIUS now. & we are back to a 1 in 3 billion chance.. Guess Malaysian got lucky

so on that aircraft You had the SAARU the Adiru & the ISFD.

If it lost the probe data you would be in a similar scenario. Does the ICE Detector work well on the A330?

[DC-ATE]

While theoretically you have two choices with this incident, Pilot Error or Aircraft/Systems failure, there really is only one choice; that of computer failure for whatever reason.

That is to say, being as how it was an Airbus with computerized everything, some part of the electronic system failed for some reason, and the pilots, no matter how well trained, could not cope with the situation. This seems to be apparent (computer problem/s) with all of the ACARS messages that were sent. Had the aircraft simply broken up, no messages (or at least not the amount) could have been sent.

On the other hand, pilot error by flying into an area of severe weather could have put the aircraft in a position the computers simply could not handle. One way or the other, I think all will have to agree, like it or not; the computers played a significant role in this incident.

The question/problem now remains to figure out how to rectify the computer problems that have affected not only this make aircraft, but others as well in the past. It would seem that computers are "here to stay" in aviation, but as the pilot gets pushed further and further "out of the loop", it would appear that we have more and more problems.

The pilot needs to have TOTAL control of his aircraft if need be at ANY time, even if it means exceeding the design limits. Basic piloting skills have been lost due to computerized flight. This fact has shown itself on too many occasions in past accidents. If this means re-installing cables, so be it. The pilot also needs at ALL times, analog flight instruments (standby 'steam gauges' if you will) to find his way to a safe landing when all of his computers fail. What good will it do to have inflight data being transmitted to the ground continuously no matter where on Earth the aircraft is, if it will not reduce the chance of similar accidents? What will it tell us? Part of the automatic system failed.....duh.

The whole idea of all this "progress" was supposed to make aviation safer. I fail to see where that has been accomplished yet. All that has been accomplished is that manufactures have been able to produce aircraft cheaper and the ticket price has gone down.....along with pilot saleries. There has been needless loss of life in recent accidents due to either loss of basic flying skills driven by computers doing the job or by those same computers failing when most needed.

[Captain-Crunch]

Swedish Steve said,
What makes you think that all three AD computors gave up?
In all the messages there is only one referring to the AD.
ADR Disagree. This infers that there is a fault with one AD output. How do you get to all three?

p.s. glad you said AD computors. Many posters here refer to ADIRU failures but it is only the AD part of the ADIRU that has failed, not the IRU part.
Today 10:51

Fair Question Steve,

I'm not basing it on the entry you mention the ADR Disagree WARNING. Because that ECAM warning only means "one or more" has a problem, right? It could be one, It could be three, we can't tell from this warning.

But unless I'm mistaken, that warning came one minute later from FAULT 34123406-IR2 1, EFCS1X, IR1, IR3,
As also an A&P, I agree with Greenspinner, that the Warnings are caused first by the Faults (FLR)

http://i337.photobucket.com/albums/n385/motidog/AF447-ACARS_4.jpg
Photo snapshot credit: Machaca & Mods


Here are the codes given to us by techs on this thread:

2131 Cabin Pressure Controller
3410 Environmental Conditions
3411 Pitot-Static System
3412 Outside Air Temp
3422 Directional Gyro & Ind.
3443 Doppler

(JASC Standard Codes)

Captain,
At this stage describe all the messages would be little bit useless, as what we need is the fault message from CMS related to these Wrn. In fact we need the full Current flight Report rather that the current leg report provided here.
Nevertheless, as I got the A330 AFR TSM in front of me, I do try to understand ,as you, what’s occurs during this flight, and despite my 17 years of experience (as line engineer) on this type of machine (A340/A330), I’ve still have difficulties to sort it out.
However for your perusal
228334 – FMGC
341234 – ADIRU
279334 – EFCS
341115 – PROBE – PITOT
That’s all the data, which could be helpful with what we have right now
The WRn messages are only 4 digits exploitable and the sixth one are mainly 00

Cheers

Greenspinner said:
You're right Fargo, and I carried out trouble shooting starting from the fault message (and not the Wrng which are the result of the fault) and guess what.
341115 lost of all pitots probe (to make it short) not duplicable faulf on Gnd
341234 lost of all ADIRU'S, not duplicable on Gnd, and digging a little bit further, lost of ADIRU pwr (to make it short also),
and all these events occurs within 1 minute....

Quote:
Ahh,

thanks Fargoo.

So, "15" is the pitot probe. Does this mean the pitot probe signal is lost to the nav computers?

Next question: What number is AOA probe?
On the small Airbus we operate normally Probe anti-ice failure (be it probe element, probe heat computer or wiring between the two) would bring up a message in that Chapter. Could quite easily be a different case on the A330 though.

34-11-16 is Static ports.
34-11-17 is Air Data Modules.
34-11-18 is TAT sensor.
34-11-19 is AOA sensor.

To decode the messages and their possible causes you need someone with access to the A330 Troubleshooting Manual (TSM).

Hope this helps a bit.

Fargoo

Furthermore, JAUH is right, ISIS it's 3422, but this kind of error exist sometime in the CMS.
However, starting again from this fault messasge,ISIS (22FN-10FC) SPEED OR MACH FUNCTION, with the red flag on the ISIS (I assume) it's lead me again to check the Stby Pitot Probe failure (9DA1, 9DA2, 9DA3)!
As the first fault recorded its also Pitot probe (341115), I would suspect severe icing (this only engage myself)

2131 Cabin Pressure Controller
3410 Environmental Conditions
3411 Pitot-Static System
3412 Outside Air Temp
3422 Directional Gyro & Ind.
3443 Doppler

(JASC Standard Codes)

Last edited by jauh : Today at 04:32. Reason: added even more stuff

ADR 1 controls the speed tape and altitude display on the Captain's PFD.
ADR 2 controls the First Officer's side.
Stand-by ADR 3 (mostly fed from the same probes as ISIS) can control the Captain or First Officer's side, if required, with some hard switching.

In case of 'ADR Disagree' message, compare airspeed indications on all three displays (the last one being ISIS). If all are the same, the warning is due to an AOA discrepancy.
If one speed display is off by more than 16 kts, switch the corresponding ADR off and switch the PFD display over to ADR 3 (if required).
If all speed displays are off by more than 16 kts and reliable ADR cannot be identified, switch ADR 1 and 2 off and fly pitch and N1 setting as per the 'Unreliable Speed Indication' paper checklist.

Sorry, I was out off sight for a while, and I’ve got planes falling down here, but rather “smooth as Silk…”


Nevertheless, here after a breakdown of all the ATA messages related to the Current Leg Report provided.


34-22-25 - INDICATOR - ISIS (INTEGRATED STANDBY INSTRUMENT SYSTEM)

34-43-00 - TRAFFIC AND TERRAIN COLLISION AVOIDANCE SYSTEM
34-12-00 - AIR DATA/INERTIAL REFERENCE SYSTEM (ADIRS) ((ADIRU & CDU))
34-10-00 - AIR DATA/INERTIAL REFERENCE SYSTEM (ADIRS)
27-90-00 - ELECTRICAL FLIGHT CONTROL SYSTEM (EFCS)
22-83-34 - FMGEC (FLIGHT MANAGEMENT, GUIDANCE AND ENVELOPE COMPUTER)
22-62-00 - FLIGHT ENVELOPE COMPUTATION
22-30-00 – AUTOTHRUST
27-23-00 - RUDDER AND PEDAL TRAVEL LIMITING ACTUATION
27-93-00 - FLIGHT CONTROL PRIMARY COMPUTER (FCPC)
34-11-15 - PROBE – PITOT
27-93-34 - FCPC (FLIGHT CONTROL PRIMARY COMPUTER)
21-31-00 - PRESSURE CONTROL AND MONITORING
27-91-00 - OPERATIONAL CONFIGURATION (F/Ctl Altn law)

for Grebllaw, 341200106 it’s ADIRU and last 2 digits 06 mean phase 06 (Cruise)
Trusting this will be of some interest
Cheers
-
-
-

But I could be wrong Steve. And forgive me guys for not giving proper credit for your previous research and posts. I'm not that organized! :8

Note: All my posts are strictly my opinion only.

.

[jr hartley]

Faulty speed meters
Mr Arslanian confirmed that the missing jet had had a problem calculating its speed, adding that it was a recurring problem on the A330s and that Airbus was undertaking a replacement programme.

http://newsimg.bbc.co.uk/shared/img/o.gifhttp://newsimg.bbc.co.uk/nol/shared/img/v3/inline_dashed_line.gif




"We have seen a certain number of these types of faults on the A330," Mr Arslanian said. "There is a programme of replacement, of improvement."
But he insisted the planes were safe in the meantime

Thats going to make the public feel secure!

[Green Guard]

Heated pitots getting iced could mean only one thing:
flying straight into the cell,

but at night during lightings, (radar misuse is excluded here),
that can happen only if pilot or pilots in cockpit
were asleep at that half an hour, (prior to coming to the cell).

And if heated pitots iced, why engines would not ?

Consequently gradual electric power loss would come!

"All asleep case" would not be first case.
That’s why FA have to come to "visit" cockpit often during sleeeepy hours.

No parts of aircraft found may suggest pilots ditched the aircraft.

:sad:

[Swedish Steve]

But unless I'm mistaken, that warning came from fault 34123406-IR2 1, EFCS1X, IRU1, IRU3,

Captain Crunch, Must admit I have never seen present leg faults presented in this fashion, I am usually looking at a PFR.
But isn't this fault IR2 fault, as reported by EFCS1, IRU1 and IRU3?

[safetypee]

PJ2, MFS, et al, apologies for yet again pushing TAT, but I wish to understand it’s potential (or otherwise) to contribute to the ACARs indications.
Thus seeking your technical expertise; what systems might an erroneous TAT affect? Considering both a large change of TAT - all inputs, or just one system in error and thus the potential to detect the difference?
What systems (computations) use TAT (e.g. ADIRU, rudder limiter via Speed/Mach, etc)?
I note the reported TAT input to the cabin pressure system.

Possible thread relevance to unreliable speed; http://www.pprune.org/tech-log/375784-pitot-icing.html#post4963257
Note other references to erroneous TAT “… sudden increase in air temperature, from -48ºC to -19ºC …” (#315). This is probably similar to the phenomena reported in an Australian BAe146 serious engine icing incident, which subsequently was revealed to be an indication problem due to frozen TAT probe – no airframe icing, but severe engine/probe icing.

[matthewsjl]

It loks to me like the ACARS FLR messages have supplemental data fields (some of which are pobably truncated on the leaked printout).

Could somebody explain what (if any) the significance of an 'X' is in the supplemental data fields. As an example one of the failures is:


34111506EFCS2 1,EFCS1,......


compared to the following entry (line higher on the printout):


27933406EFCS1 X2,EFCS2X,......


Thanks, John.

[Captain-Crunch]

Captain Crunch, Must admit I have never seen present leg faults presented in this fashion, I am usually looking at a PFR.
But isn't this fault IR2 fault, as reported by EFCS1, IRU1 and IRU3?

Correction: They are not listed as IRU's, rather they are IR's..sorry: typed what I wanted to see there....

Steve, It appears to be an internal mtc leg report broadcast on French T.V.
I don't have the A330 TSM or AMM to reference. I'm just going by the research of the techs here at pprune. But the codes have been independently broken down by several airbus mechanics, and thought there are small differences in nomenclature (common) between versions, they match, which gives me a warm-fuzzy. Have all three IR inputs faulted on that line? update: [GreenSpinner thinks so after research, but his colleague below affirms your impression that it's just #2IR (U)] :confused: Stay tuned.

The section is 34 (Nav) and the sub-grouping is 12 (OAT sensors) and the item status is 34 (ADIRU). If we could persuade GreenSpinner to scan us a T/S flowchart that would be awsome. But that's asking a lot. I'm not sure we pilots would understand it anyway! :}

CC

Note: All my posts are strictly my opinion only.

[forget]

If we could persuade GreenSpinner to scan us a T/S flowchart that would be awesome.

I just hope that Greenspinner (:ok:) has not been put off by Odies out of place remarks. I don't think Odie realised that GS has spent 17 years fixing Airbuses and deciphering ACARS.

[avspook]

Quote:
Swedish Steve
But isn't this fault IR2 fault, as reported by EFCS1, IRU1 and IRU3?


That is correct.. An example would be a loss of data from IR2 data to the reporting LRU's

[Safety Concerns]

After trying to make sense of the acars messages the past 24 hours there is a scenario/situation that would explain 23 of the 24 acars messages. I would like to share it in order for others to decide if it has any loopholes but I don't want to be kicked for speculation.

Any ideas or post it on another thread?

[ihg]

Most of the speculation on the reason for the AF447 disappearance is based on two things:

- satellite images
- ACARS messages

With respect to the last one: Many of you think, that theses messages can provide a "sequence of events".

But is this really possible?

ACARS has not been designed as a "real time monitoring system". So, as I have no detailed knowledge about the ACARS implementation on the A330, I would have some questions before "abusing" ACARS as this:

- What is the usual internal sampling rate of the ACARS system? How often does it read out the error memory of the respective systems?
- How often does it usually send messages? Does it send messages as soon as a new system error appears? What's the time lag between error occurence and error message sent via ACARS?
- Can one message contain multiple errors? Or will each error transmitted in a separate message?

To put it the other way round:
If e.g. 10 errors would appear simultaneously, how would ACARS deal with that?
Assuming that each error would be send in a separate message, how long does it take to send all these messages?
Is the time stamp on these messages, the time when the message was sent or the time when the respective error occured?

Thanks in advance,

ihg

[Safety Concerns]

there are issues with acars but the messages sent are time stamped by the system reporting the failure. As all systems are on the same time bus you can get an accurate picture.

What you can't account for is the sampling rate of the system but this generally applies to normal conditions i.e. some air conditioning sensors are monitored every 3 minutes. However a significant fault or warning is time stamped in real time.

That doesn't prevent the scenario however that there were other messages relating to earlier incidents that didn't make it to the transmitter for whatever reason

[rouelan]

I note that, this morning, BEA talked of 24 ACARS msgs sent within 4 mns.
When comparing with doc leaked, I also count 24 msg.
Which suggests that BEA is working on exactely same piece of info.
Then I cant reconciliate with the fact that they pointed out a problem air speed incoherence ?

[positive climb gear]

My background is the A320 series, but believe the A330 is similar! I have noticed that some of the older aircraft I fly gives you the ability to switch off EITHER the Air Data or Inertial Reference feed to the respective ADIRS.

However, our latest aircraft just has the one switch- is this particular series of the A330 similar? thus would switching of the ADR also depower the IR reference also?

[OVERTALK]

Lots of discussion about pitot tubes instantly icing up as an explanation for the airspeed disparities/anomalies? There's a much simpler (Occam's razor) explanation - if you go back to first principles.
” New information provided by sources within Air France suggests, that the ACARS messages of system failures started to arrive at 02:10Z indicating, that the autopilot had disengaged and the fly by wire system had changed to alternate law. Between 02:11Z and 02:13Z a flurry of messages regarding ADIRU and ISIS faults arrived, at 02:13Z PRIM 1 and SEC 1 faults were indicated, at 02:14Z the last message received was an advisory regarding cabin vertical speed. That sequence of messages could not be independently verified.”

On basics it means: the AP disconnects when gets to the limit but the aircraft is already in an unusual attitude, then it reverts to alternative flight control, then this is followed by ISIS and Inertial failures, then PRIM1 + SEC1 computer failures and finally a sudden decrease in cabin pressure (when the aircraft is already divided in parts), multiple electronics failures as the aircraft is disintegrating.

All this happens between 2:10Z and 2:14Z

Looking at the incident described in post 316 (http://www.pprune.org/rumours-news/376433-af447-16.html#post4978418), we can imagine what would have happened to AF447, upon entering such a "warm pool", if the autopilot had remained engaged - and the incident allowed to develop. Quite simply, wing and nose drop plus yaw (aka autorotation) at a high power setting as the autopilot and autothrust tried to maintain the flight level - despite, due to the warm pool, suddenly being overweight for the environmentals.

It's called coffin corner. Aerodynamic stall and Mach buffet boundaries come together to define the upper edge of the aircraft's flight envelope. Autorotation (aka spinning) at a high power setting is going to have some further complicating ramifications:

a. firstly, engine intakes are going to be blanked and, being already close to their surge margins at that height, at least one engine will stall/surge...... complicating the autorotation with asymmetric thrust (as per the Jefferson City crash of a Pinnacle CRJ200).

b. Autopilot would disconnect and control law would change

c. ACARS transmitted indicated airspeed anomalies between left and right ASI's? In a spin, the F/O's pitot and static ports being on the other side of the airplane (to the captain's), the pitot and static sensed pressures will be in error (and also quite unalike) and so the ADIRU's are going to be initially integrating different air data and therefore calculating different speeds. That ADIRU disagreement will generate faults.

d. The situation at C will be beyond anything the ISIS has ever been programmed to cope with, so a fault message will be generated.

And thus the flow of ACARS messages begins:
Fourteen of those messages, says the Bureau d'Enquetes et d'Analyses, were sent within the space of one minute, from 02:10UTC to 02:11UTC. This would have been immediately after the spin entry.

Subsequent ACARS messages (until 2:14Z) resulted from the descent into the storm clouds below and the transition into the unstable steepening spiral (G increasing until breakup thresholds were exceeded). The entire process (to breakup/no further messages) took 4 mins.

I'd imagine that, once into a spin, the centripetal(wrong) centrifugal forces on the flight-deck would've precluded any useful action or allowed any thoughts of transmitting a Mayday. The final cabin pressurization warning would've been immediately prior to total electrical power-loss (due to the first hull rupture preceding a general break-up due to the classic high-speed/g-tightening spiral).

Any amplification of this as a probable scenario (from the available ACARS messages)?

Any exceptions as to the likelihood of this exact scenario?

At least it would seem to credibly explain the airspeed discrepancies that otherwise seem to have everybody flummoxed. Not sure if the Airbus simulators could replicate this, but then again we've all seen what happens to airspeed in different types of spins (stable/unstable).... it fluctuates. Once the A330 descended into thicker air the spin would become an unstable spiral with its characteristics quite dependent upon residual thrust, C of G position and flight control trim settings. In the turbulence and in IMC with no functional flight instruments, a destructive break-up would be inevitable.
.
edit to change to "centrifugal"

[marsipulami]

Overtalk, you are drawing some very sensible conclusions regarding to that weather phenonoma described in post 316. All of a sudden you find yourself outside your envelope with consequently odd indications in terms of speed which might have led to the stream of ACARS messages. Though, we simply don't know yet.

I've heard a few similar stories of pilots crossing the ITCZ and encountering such a "pool of warm air" with the associated turbulence.
For them it was only a matter of time when they came out of the pool unharmed due their relative low weight at that time.

Marsipulami.

[UNCTUOUS]

OVERTALK

Logical.
Quite similar to the high altitude departures of:

China Airlines 747
ASN Aircraft accident Boeing 747SP-09 N4522V San Fransisco, CA, USA (http://tinyurl.com/n2rfds)

TU154
ASN Aircraft accident Tupolev 154M RA-85185 Donetsk (http://tinyurl.com/q6vk7z)

and others......

[TheShadow]

OVERTALK
Brings to mind also the loss of an RAAF 707 tanker off East Sale some ten or more years ago (although that was a VMC air exercise gone horribly wrong). The low-speed departure due to asymmetry and flight control limitations seem similar.

I imagine that a departure into autorotation of a multi-engined heavy would be non-recoverable.

[concordino]

Pool,

I beg to differ with you on this one:

Redundancies are here to exclude failures

If redundancies are to exclude failures, why is it a redundancy then ?
The whole concept of a redundancy is primarily based on the concept of failure. The pilot is not a system, it is liveware and not hardware such as ADRs etc etc...

The pilot carries a redundancy due to his/her Training/Experience/Skills but i am afraid that is even a more limiting factor at times...a topic in itself.

The same way redundancy is built into systems, protections must be included in the most extreme combinations of failures. I am not asking for more protections. i am asking for the same protections available under more extreme failures or comibinations of thereof.

Afterall it is FBW as you stated. So it is either a fully functioning marvellous system or a backup mode that makes you recover and fly the plane like a conventional one.

[Dagger Dirk]

In light of OVERTALK's explanation at post 344 of the airspeed discrepancies, wonder if Air France are just wasting their francs doing this: (i.e. I suspect that they ARE)
Air France gave a possible clue to the loss of its Flight 447 last night by announcing it was to replace a vital instrument sensor on all Airbus jets.
The memo was sent to all the airline's pilots, but the company refused to comment on it saying it was confidential.
Airbus said the move was part of the investigation into the crash that killed 228 people flying from Rio de Janeiro to Paris.
The memo said Air France has been replacing the instruments - known as pitot tubes and responsible for feeding flying speed data to the aircraft's instruments and computers. It said it will finish the task in "coming weeks".
One theory of the crash is that the pitot tubes may have iced over, giving incorrect information which then led to the plane flying too fast or slow in rough weather.
Air France orders vital components replaced on jets - World news, News - Belfasttelegraph.co.uk (http://www.belfasttelegraph.co.uk/news/world-news/air-france-orders-vital-components-replaced-on-jets-14329308.html)

.

[Swedish Steve]

Did I miss something... First message on the fault list
"ctl rud trv lim fault"

I have explained this before. The rudder travel limiter uses two airspeed inputs from ADIRUs. If they are not the same it will post a fault. It will not move.

[aguadalte]

I have explained this before. The rudder travel limiter uses two airspeed inputs from ADIRUs. If they are not the same it will post a fault. It will not move.

Sorry to disagree. Yes it will move. That is why you will get a "Use Rudder With Care" message in Status Page.

[Mark in CA]

Alain Bouillard, head of the French investigation, said, "They hadn't yet been replaced," referring to the pitot tubes on AF447 that Airbus had recommended be replaced on all A330 aircraft. Air France had not yet acted on the recommendation and refused to comment.

Probe: Airline did not replace instruments on 447 - Yahoo! News (http://news.yahoo.com/s/ap/20090606/ap_on_re_la_am_ca/brazil_plane_152)


“The sensors on this aircraft had not yet been replaced,” said Paul-Louis Arslanian, director of France’s Bureau d’Enquêtes et d’Analyses, known as the B.E.A.

A spokeswoman for Airbus in the United States said in an e-mail message on Saturday that the recommendation for the replacement of the Pitot tubes was “not a safety issue.”

http://www.nytimes.com/2009/06/07/world/europe/07plane.html?partner=rss&emc=rss

[John47]

It would appear that AF were replacing pitot tubes anyway

"In 2007, Airbus advised operators of the Airbus A330 that were equipped with Pitot tubes manufactured by the French company Thales to replace them.

Stefan Schaffrath, an Airbus spokesman, confirmed that this recommendation, known as a service bulletin was made, but said it was for reasons of improved performance rather than safety concerns.

“The advice was issued because there was a new generation of device out there with improved performance regarding its measurement capability,” Mr. Schaffrath said. “This is nothing unusual as there are constant updates ongoing throughout the life of an aircraft.”

Airbus said it had informed air safety regulators in Europe and North America about the recommendation at the time. But on Friday a spokeswoman for the Federal Aviation Administration was not able to confirm this, and said there were no plans to turn this recommendation into a requirement."

http://www.nytimes.com/2009/06/07/world/europe/07plane.html?_r=1&hp

[max motor]

Sorry to disagree. Yes it will move. That is why you will get a "Use Rudder With Care" message in Status Page.

I think he means the LIMITER won't move (which means the rudder has full travel).

Max

[S.F.L.Y]

In light of OVERTALK's explanation at post 344 of the airspeed discrepancies, wonder if Air France are just wasting their francs doing this (changing pitot probes): (i.e. I suspect that they ARE)

Well, AF decided to change these probes before the accident due to previous incidents. In fact Airbus pitot probes were already redesign in the 90s as they were already involved in airspeed discreapencies while flying in heavy precipitations or freezing conditions, sometimes leading to AP/ATHR disconnections, F/CTL ADR disagree and F/CTL ALTN LAW.

This problem is basically known and documented by Airbus since 95...

[alph2z]

I think he means the LIMITER won't move (which means the rudder has full travel).

Does that mean that the LIMITER will limit to its last valid min, max, or intermediate rudder travel ?
.

[TyroPicard]

The rudder will move in response to rudder pedal movement, but the device which limits the travel at high speeds will be using the wrong speed as a reference - so you may get too much movement.

OVERTALK
You got there just before I did as I was ploughing through the pages - I was going to ask if anyone knows what the roll limits are for the IR's and ISIS, whether they have full freedom or cannot survive a 360 degree roll. Because, as BOAC alluded to earlier, how does icing make an IR fail?

[Bearcat]

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.

[BOAC]

But, Bearcat, is that not what a crew would do if that SAT change hit them? Surely when you see speed reducing at thrust limit there is only one choice. Either we have yet ANOTHER 'automatics are in control and all is ok' event or something else 'hit' them (For CNN and The Daily Mail I do NOT mean a meteorite:mad:)?

[GobonaStick]

Report coming in that searchers have found first victims. :(

[Hostie from Hell]

Some of the messages on PFR are insignificant with reference to Maint status items..plus those covered by ATA 22..Autopilot. Signficant data appears to be air data reference disagree, fligt control alternate law and rudder travel limiter fault. The latter if both 1 and 2 RTLs are at fault could allow full rudder input thus, subject to aircraft input, overstress the vertical stabiliser. ADR disagree could be as a result of assymetric severe icing conditions. As a result of flight control altn law fault I believe that flight envelope protection may have been compromised allowing inputs to exceed safe parameters levels. So possible causes would originate through the severe weather experienced but ultimately the loss of the aircraft may be contributed by the loss of the flight envelope protection. I will emphasise that this is pure speculation having read the ACARS PFR and without reading any previous threads.

[FIRESYSOK]

That's not exactly bad news now (if) they've focused the search. Regarding the ISIS, there are many faults possible with the device. Could it tumble? Theoretically it is a solid-state device and not prone to that, but in a severe upset anything is possible. A power interruption also may corrupt the operation of the device. I've had one fail in flight giving a generic FAULT code and a blank screen. Who knows but the engineers all the fault modes possible...

[wiggy]

From Le Figaro

Le Figaro - Flash actu : Vol AF 447 : des corps ont été récupérés (http://www.lefigaro.fr/flash-actu/2009/06/06/01011-20090606FILWWW00484-vol-af-447-des-corps-ont-ete-recuperes.php)

[BOAC]

Anyone know if we can confirm or chuck out the 'Warm Pool' theory from IR weather satellite images?

[RiverCity]

CNN is quoting the Brazilian Air Force with the same information.

[Flyinheavy]

Brazilian Air Force informs to have found first victim about 70 km from the last position that has been reported by the a/c. Whatever this last posn means.

More specifically they are talking 'where the last communication from the aircraft was received'.

[aguadalte]

Quote:
Sorry to disagree. Yes it will move. That is why you will get a "Use Rudder With Care" message in Status Page.
I think he means the LIMITER won't move (which means the rudder has full travel).

Max

Thanks Max, Sorry Swedish,

On the A330, if you get a double rudder limiter fault, the TLU may be left positioned in such way that it will not prevent the pilot from using more rudder than the structure can accept. (Full rudder can only be used below 160Kts).

[Tail Chase]

The Brazilian AF issued a number of releases earlier this afternoon, indicating that two bodies had been located and retrieved, along with a personal effects and (apparently) small aircraft components. The sequence of events this Saturday is as follows:
1.) 0300LT/06062009 Brazilian AF R-99B 6751 departed from SBFN to scour the debris field originally plotted early last Tuesday morning (02JUN2009), in which a passenger seat and a 7-meter long component were later visually sighted by one of the C-130Hs.
2.) 0814LT/06062009 Two bodies were visually plotted inside the search area
3.) 0930LT/06062009 The first body (male) was retrieved
4.) 1113LT/06062009 The second body (male) was retrieved
5.) 1200LT/06062009 A knapsack was retrieved, along with other smaller personal items

Cheers

[Pontius Navigator]

I'm curious about the use of the term "bodies" vs human remains.

We must be careful attibuting English elegant variation to translation from foreign sources.

~~~~

From the position of the bodies it will be possible to backplot using wind and current data to determine a point of entry into the water. A US expert used the term Hindcasting (sic?).

[Tail Chase]

Further to my previous post, Brazilian Navy corvette Caboclo is currently carrying out retrieval duties. After collecting the two previously mentioned bodies, the ship´s crew retrieved passenger oxygen masks, a blue-upholstered passenger seat (with serial number) and a large number of personal effects.

The two bodies were found some 900 km from SBFN

Cv Caboclo will remain on site to search and collect whatever it finds until late this afternoon and Sunday morning, when it will transfer all that it collected to the frigate Constituição. The frigate will then sail to a point 250 km E of SBFN, when it will launch its Super Lynx helicopter to SBFN with bodies and whatever material was collected by the Caboclo. Bodies and material will then undergo preliminary identification and will subsequently be flown to SBNT.

Cheers

[Grunf]

If this is true it is weird - AD is COMPULSORY within the time compliance requirement (which was 2003).

So not complying with an AD is a really weird thing, if true.

Cheers

[Squawk_ident]

French media are announcing the same thing.
A seat, a bag with a laptop inside and an AFR ticket. Two male bodies have been recovered and are on board a Brazilian vessel.
A German military satellite would have located an aera with possible debris of the plane.
A French submarine is on its way and will try to locate a signal from the bottom of the ocean. Unfortunately it will take a while before it reaches the area.
Regards

[rer47]

Earlier mm43 calculated aircraft speeds and positions based on an assumed speed at INTOL of 540kts.
The references I have seen give the speed at INTOL as 453kt (see reference 15 in the Wikipedia article).
Assuming this ground speed, the results change considerably:

INTOL 0133Z
453kts
EPODE 0157Z
453kts
ORARO 0205Z
576kts
FINAL 0214Z

Assuming FL350 and an OAT of -43C (from Vasquez (ref 25), but ignoring his estimated 10kt headwind), 453kts corresponds approximately to M 0.78, evidently the recommended speed for turbulence. 576kts corresponds to M 0.98, which is impossible. Therefore they must have increased speed long before ORARO. This would be consistent with overspeed and destruction of the aircraft due to turbulence.

As reported by others, two bodies have been reported found about 900 km (revised to 800 km - BBC) NE of Fernando de Norohna (refs 53, 54). The final ACARS location is 858 km NE of that island.

rer47

addendum: A Brazillian news paper reports "470 miles - about 900 km from Fernando de Norohna" and "69 km from the final location communicated". This would be nm, and the last location would be the 0214Z message (FINAL).

Aeronáutica confirma descoberta de destroços e corpos - Estadao.com.br (http://www.estadao.com.br/noticias/cidades,aeronautica-confirma-descoberta-de-pecas-e-corpos-de-vitimas,383405,0.htm)

[philpop]

More details of the ACARS messages have become available on June 5th and suggest following events while the airplane was in cruise (note, there is no message regarding electrics, hydraulics or engine problems):

02:10Z: Autothrust off
Autopilot off
FBW alternate law
Rudder Travel Limiter Fault
TCAS fault due to antenna fault
Flight Envelope Computation warning
All pitot static ports lost
02:11Z: Failure of all three ADIRUs
Failure of gyros of ISIS (attitude information lost)
02:12Z: ADIRUs Air Data disagree
02:13Z: Flight Management, Guidance and Envelope Computer fault
PRIM 1 fault
SEC 1 fault
02:14Z: Cabin Pressure Controller fault (cabin vertical speed)


There have been at least two similiar incidents preceding AF-447 (dates of both flights are unknown):

First incident: An Air France Airbus A340-300, registration F-GLZL performing flight AF-279 from Tokyo Narita (Japan) to Paris Charles de Gaulle (France), was enroute at FL310, when the airplane went through a line of thunderstorms. The captain's air speed indication suddenly dropped to 140 knots, the systems issued an alert regarding disagreeing speeds (NAV IAS DISCREPANCY), the navigation display showed a tail wind component of 250 knots. The captain released control of the airplane to the first officer and tried to switch his display from ADIRU1 to ADIRU3. 2 minutes later autopilot and autothrust disconnected and the fly by wire changed into alternate law. The crew noticed icing conditions (static air temperature [SAT] -29 degrees Centigrade) and switched anti ice including pitot heating systems from automatic to on. The speed indications became normal again and agreed again, the autoflight systems were reengaged and ATC informed of severe icing. ATC reported, that two flights had just passed the location without problems. When the crew attempted to reset and reengage ADIRU 1 two times, the system again brought the message "NAV IAS DISCREPANCY" on both attempts, although the speed data appeared consistent. The crew suspected polluted pitot tubes.

Maintenance found, that the drainage holes of all three pitot tubes had been clogged, rendering it very likely that weather combined with the clogged drainage holes caused the incident. Maintenance had reported more clogged drainage holes on A330 and A340 aircraft in the past to Airbus Industries. Airbus Industries was aware of the problems, changes had already been introduced to the pitot tubes on the A320 family, where similiar problems had occured. A modification of the A330/A340 pitot tubes was already planned by AI.

Second incident: An Air France Airbus A340-300, registration F-GLZN performing a flight from Paris Charles de Gaulle (France) to New York JFK,NY (USA), encountered brief turbulence while enroute. The autoflight systems dropped offline, "NAV IAS DISCREPANCY", "NAV PRED W/S DET FAULT" and stall alerts were repeatedly issued during the following two minutes. The airplane continued to JFK without further incident. A review of the policy of retrofitting pitot tubes was recommended and authorities informed.

[AMF]

ByteJockey

http://www.faa.gov/other_visit/aviat...overy_Book.pdf


ByteJockey,

I have no idea why your post would be deleted. That FAA link should be required reading for anyone interested in thinking about possible causes for this accident and every driver operating at high altitude. For the uninitiated, it's filled with useful facts and info like this relating to high-altitude flying....

"In another high altitude situation, the crew decided
to use heading select mode to avoid weather while
experiencing turbulence. The steep bank angle that
resulted from this mode quickly caused slow speed
buffeting. The crew’s rapid inappropriate response
to disconnect the autopilot and over-control the
airplane into a rapid descent in poor weather exacerbated
the situation. These real world examples
provide evidence towards the need for more detailed
training in high altitude operations."

While it is all pertinent, of particular note should be areas of interest that could be directly related to the conditions the AF was operating at the time and possible factors; High Altitude Aerodynamics, Thrust Limited Condition and Recovery, Maneuvering Stability, Effects of Wx that could cause Stall or Slowdown at High Altitude, Use of Anti-Icing on Performance, Inflight Icing Stall Margins, Flight Techniques of Jet Aircraft, Human Factors and High Altitude Upsets, Multi-Engine Flame-out.

Understanding those basics of high altitude flight, and transposing what is known or probable about AF at 35,000' (which was still relatively heavy operating near the top of it's weight-defined envelope), that conditions were turbulent and possibly severe, that the A/P disengaged itself and the crew were hand-flying (without numerous protections), that there were airspeed anomalies or miscompares whether they be vertical gust, icing, turbulence or a combination of all-induced within or (in the case of vertical gusts and turbulence) in the clear above quickly developing convective activity, and the possibility that the aircraft entered an area of rapidly increasing temperatures aloft as it traveled laterally through uplifted warmer moist air and it's evident that there is no reason an aircraft need be broken, malfunctioning, or giving erroneous information to the crew to find itself in a perilous and rapidly deteriorating aerodynamic (and possibly untenable) situation if recovery is thrust limited and the attempted recovery executed in severe conditions of turbulence, icing, vertical gusts, and possible engine problems associated with loss of aerodynamic flow/control.

It doesn't matter if it's an Airbus, Boeing, or the latest whiz-bang corporate jet...no aircraft escapes these Laws of Aerodynamics or magically isn't affected by what Mother Nature can hand it at those altitudes just because every system is working.

No aircraft is designed to fly at or near the upper limit of it's envelope without strict adherance to load-factor/bank, and AOA limits, and the difference of being near the edge of that envelope as opposed to even 5,000' lower in terms of riding through turbulence/limits on maneuvering inputs to observe them, and having excess thrust to overcome rising-temp or turbulence/vertical gust-induced airspeed degradations/fluxuations are night and day.

If the previously posted QRH numbers are anywhere close...that for that altitude and approximated weight, and assuming the crew slowed the aircraft to below its Maximum Turbulent Air Penetration Speed when the pilot messaged 10 minutes prior to the ACARS message flurry, the margin for control between overspeeding and min clean speed was merely 15 knots at that altitude and weight, and only 25 knots between overspeed and min speed/stall buffet. And within that small airspeed window load factor/bank limits must be observed or the low-speed buffet boundary rises rapidly.

If the bank angle gets too excessive (whether turbulence or pilot-induced, and at high altitude "too excessive" is simply a standard bank at low altitude) it's possible for the low-speed buffet boundary to rise (and it's rise corresponds to the rate of roll...i.e. very quickly in turbulence) the point it crosses over the aircraft's current speed which will produce an immediate stall. If the bank angle continues this low-margin buffet can cross-over past it's Max Turb Speed and over the aircraft's Mmo/overspeed and the "corner" available for flight doesn't exist. At high altitude the pilot's ability to counteract turbulence-induced roll to stay within load-factor AOA limits is seriously hampered by sluggish response to control inputs. It's entirely possible that vertical gusts acting unevenly on the aircraft or roll axis occillations associated with varying turbulence amplitude can't be counteracted quicky enough by pilot inputs, and in severe turbulence, guaranteed, because the aircraft experiencing at least momentary loss of control is part of what defines severe turbulence.

Momentarily losing control of the aircraft in severe turbulence at lower altitudes means that although for a moment the pilots couldn't counteract the environmental, outside force acting on the aircraft the aerodynamics remain far more sound, and once the outside force abates (if the aircraft isn't structurally damaged) control can be quickly regained with the help of authoratative control response and excess engine thrust availability. Since at low level the performance envelope between high and low speed buffet boundaries is far wider and bank angle/load factor limitations far less restrictive, the aircraft may never go outside the associated larger operating envelope.

This is not the case at high altitude where the aircraft is operating near to the top edge of it's envelope where speed buffet boundaries and roll limits small even in smooth air. Due to these thin margins, turbulence or vertical gust forces and fast temperature changes can quickly place the aircraft outside any or all of these limits (possibly at the same time) but when it abates it leaves the aircraft well outside it's envelope and fully in the realm of unsound aerodynamics where flight control inputs are degraded, and overcontrolling or wrong input can quickly exacerbate the problem. To make matters worse, engine thrust available to help regain the envelope is minimal or non-existant if a flame-out occurs.

For the non-pilots who have an interest in this;

It's hard to explain to the uninitiated just how differently an aircraft flies when near the top of it's operating envelope compared to just a few thousand feet lower, and what these degradations and thin margins mean. If you're near the top end of that envelope, even something as little as a unforecast, sudden rise in temperatures aloft of 5 to 10 degrees can require immediate action (descent to a lower altitude because engine thrust isn't available in excess at altitude) because the top of the envelope is lowering...crashing down if the temp rise is quick enough.

The same goes for encountering even moderate turbulence with regards to bank/load factor limits. Turbulence at altitude is not simply a matter of comfort or breaking the airplane like it is at lower altitudes...its a matter of the aircrafts ability to remain flying as the low-speed stall margin rises up to approach your current airspeed every time the rolling action is induced. The greater/quicker the bank, the higher/quicker the rise. This is why at high altitude autopilots automatically limit roll to about 1/2 the bank (appx 15 degrees) of what it normally rolls the airplane to at lower altitude. This roll-limiting feature for most autopilots usually becomes active automatically when climbing through 30,000 to 33,000 feet and the aircraft enters the higher-altitude realm of small-margin aerodynamics.

Coupled with this of course is the whole necessity of coordination with using rudder and it's limits, dutch rolling and yaw tendencies at altitude for every type of aircraft, and how ocillations can develop during turbulence with receding and leading wing local velocities that (due to small buffet boundary margins) can actually approach low-and-high buffet at the same time on difference sides of the aircraft if they increase in amplitude.



When hand-flying, a pilot must still observe the critical limits even while counteracting turbulence/fluxuations that are trying to force (or has already forced) the aircraft past them. It's my understanding that with the A/P disengaging the way it did on the AF flight as indicated by ACARS message, even as a Fly By Wire aircraft that normally has overbanking protections built-in while being hand-flown, while operating in Alternate Law (as it was this case as indicated by another ACARS message) this particular overbanking protection (among others) is removed, and it will essentially fly and maneuver like every other aircraft.

At high altitude, heavy, and near the top of its evelope, that means "poorly". Basically, high altitude flying is potentially one of the biggest can of worms in aviation.....high altitude flying in severe weather quickly opens it, and nothing on the aircraft need be broken or malfunctioning for it to be perilous.

And if aerodynamic control is is lost and can't be regained, Air data readings...which are designed to read accurately when the aircraft is flying soundly, not in the middle of lost aerodynamics situations or possibly wildly fluxuating outside conditions as found in extreme weather/updraft/downdrafts.....will predictably be inaccurate, fluxuating, and conflicting/miscompare between systems which could easily produce some of the subsequent ACARS messages that people are assuming mean either component source failures or sensing malfunctions.

[innot]

what I find unreal is the temps to go from -46 to -18c in fell swoop

It is not as unreal as it sounds. Last year on an A340, while flying through what was probably the remains of previous days CBs, we had some spectacular St. Elmos fire. The whole airframe was glowing, lightning coming out of the radom etc. Also the TAT increased dramatically, from -30 to almost 0° within approx. 5 minutes. I was sure this was caused by the electric discharges heating up the TAT probe, but nevertheless the upper and lower limits on the the speedtape came uncomfortably close.

As we did not want to find out what would happen if the apparent temperature pushed as out of the envelope (overspeed and stall protections at the same time?), we were about to start an immediate descent when we suddenly left the area and the TAT fell back to -30° within seconds.

There was nothing on the wx-radar and the turbulences were only light to moderate.

I would not completely rule out something like this happened to AF447, but I think it is very unlikely and other theories seem more plausible.

Just my 2 cents

Thomas

[Junkers388L]

TCAS fault due to antenna fault

Could anybody confirm that this is really the correct interpretation of the error code 3443005 given in the ACARS message?

Since the Air France ACARS printout has this as "WRN", I would believe this is a consecutive error resulting from the 341115 Failure ("FLR") error code reported also at 02:10Z, right?

Potential explanation of a consecutive error could be the TCAS dependence on pressure altitude. With respect to the ACARS message time stamps, I think we need to compare them to the logical interdependence of the systems to give more substance to the analysis.

Would be great if Greenspinner et al. could shed some light on this, since I have no access to A330 material at this level of detail....

[S.F.L.Y]

OPERATORS HAVE REPORTED AIRSPEED DISCREPANCIES WHILE FLYING UNDER HEAVY PRECIPITATIONS OR FREEZING CONDITIONS, WHICH SOMETIMES LED TO THE A/THR AND THE AP DISCONNECTION, THE E/W "F/CTL ADR DISAGREE" AND "F/CTL ALTN LAW"........

STRONG CUMULO-NIMBUS CONTAINING A HIGH DENSITY OF ICE CRYSTALS CAN BEE ENCOUNTERED, PARTICULARLY IN THE INTERTROPICAL CONVERGENCE ZONE (ITCZ)
IN SUCH AND ICY AND TURBULENT ATMOSPHERE, THE A/C AIR DATA PARAMETERS (PRESSURE DEPENDANT) MAY BE SEVERELY DEGRADED, EVEN THOUGH THE PROBE HEATERS WORK PROPERLY.
IT HAS APPEARED THAT THE CHARACTERISTICS OF SUCH AN ENVIRONMENT COULD EXCEED THE WEATHER SPECIFICATIONS FOR WHICH THE PITOT PROBES ARE CURRENTLY CERTIFIED.


http://nsa07.casimages.com/img/2009/06/06/09060605551376060.jpg

http://nsa07.casimages.com/img/2009/06/06/0906060555559890.jpg
(http://nsa07.casimages.com/img/2009/06/06/0906060555559890.jpg)

[Safety Concerns]

Thats why it is strange that they are talking about known issues. These issues were dealt with and a new probe had to be in place by 2003. It was a mandatory sb.

I think the BEA and Air France need to clarify what they are saying.

Also a fleet replacement programme has ETOPS consequences so I am sure Air France are staggering the replacement and not replacing all 3 at once.

I ask this because there is still an open issue of blocked drain holes on the probes which could lead to serious consequences particularly in stormy weather.

[S.F.L.Y]

Maybe that the 2003 new probes were still inefficient. Now the questions are:


Why airbus, civil aviation authorities and operators decided to allow operations knowing these issues (especially the latests in 2008)?
How many crews were informed of these issues?
How many aircrafts with these probes are still flying?
Will these aircrafts keep flying tomorrow and with which safety guaranties?

[sequ]

Wasn´t this 330 manufactured in 2005?

Whatever was required by this SB should have been complied with during manufacture.

I think this is a moot point.

Saludos,

SEQU

[barrymung]

02:10Z: Autothrust off
Autopilot off
FBW alternate law
Rudder Travel Limiter Fault
TCAS fault due to antenna fault
Flight Envelope Computation warning
All pitot static ports lost
02:11Z: Failure of all three ADIRUs
Failure of gyros of ISIS (attitude information lost)
02:12Z: ADIRUs Air Data disagree
02:13Z: Flight Management, Guidance and Envelope Computer fault
PRIM 1 fault
SEC 1 fault
02:14Z: Cabin Pressure Controller fault (cabin vertical speed)"

Whilst I can see that blocked pitot tubes could cause all manner of spurious error messages, I fail to believe it'd cause things like "TCAS fault due to antenna fault" or even "failure of gyros".

[Swedish Steve]

Barrymong, your quote is someones interpretation of what happened.
It is not accurate.
What is a pitotstatic port? A330 has pitot heads, and static ports. They are metres apart.
ISIS doesn't have gyros, it has a solid state sensor.
ADIRUS did not fail, the AD part of one disagredd with the others. There is no evidence of the IRU part failing.

Try a different source before you jump to the wrong conclusions (or better still read the whole thread)

[Safety Concerns]

2 from 3 pitot probes supplying erronous data would account for 23 of the 24 messages. The only message that it wouldn't cover is the IR2.

[PJ2]

SEQU;
Wasn´t this 330 manufactured in 2005?

Whatever was required by this SB should have been complied with during manufacture.

I think this is a moot point.
Fully concur.

The AD was issued to be effective in November of 2002. The AD (http://www.casa.gov.au/wcmswr/_assets/main/airworth/airwd/adfiles/over/a330/a330-001.pdf) applied specifically to -300 series A330's and not the A330-200. Here are the applicable paragraphs:
AD/A330/1 Pitot Probes 12/2002

Applicability: A330-301, -321, -322, -341 and -342 series aeroplanes, all serial numbers without either Airbus Industrie modification 44836 or 45638 embodied during production or Airbus Industrie Service Bulletins (SB) A330-34-3038 or A330-34-3071 embodied whilst in service.

Requirement: Remove Rosemount pitot probes part number (P/N) 0851GR and replace them with either BFGoodrich Aerospace P/N 0851HL probes in accordance with SB A330-34-3038, or by Sextant P/N C16195AA probes in accordance with SB A330-34 3071.

Note: DGAC AD 2001-354(B) refers.

Compliance: Before 31 December 2003.

This Airworthiness Directive becomes effective on 28 November 2002.
You are correct in your observation, that this AD would have been incorporated in the manufacture of the aircraft in April of 2005.

There may be other factors which are exhibiting issues related to pitot tubes and information becoming available, but focussing on the notion that the accident sequence was "initiated" by AF not changing pitot tubes is incorrect.

[Safety Concerns]

@pj2 which is why BEA and Air France need to clarify what they are saying.

There are no open issues with pitot probes and there are not any new requirements to replace them only the old one. SO what are they saying?

It is however confirmed that Air France are replacing the probes. It doesn't add up.

So on the contrary people are thinking and relevance to the sequence of events at the moment cannot be ruled out

[barrymung]

"Swedish steve" I'm not jumping to any convclusions, just asking for clarification as to how blocked pitot tubes can be responsible for the stream of error messages that were sent.

The conclusion I come to is that they can't.

Either the list of error messages is incorrect -or- something else/extra happened

[Safety Concerns]

barry try again.

all flight control, adr disagree, pfd flags and autopilot faults can be caused by blocked probes.

how many does that leave?

[barrymung]

I have never heard of a blocked pitot causing an antenna fault, for example..

[Safety Concerns]

if only people would investigate rather than opinionate.

TCAS is fed air data information from the ADIRU's. If you already have faults or issues with the ADR part the data bus going to TCAS will log a fault.

Once again 23 of the 24 messages can be traced back to air data.

[lomapaseo]

We need to be careful about following the lead of the news headlines in identifying the cause of an accident. The news deals in headlines and simple thinking of black and white. Our discussions in this forum should deal in combinations as weighted causal factors.

So far we have inferences of

lightning
turbulence
Speed disagrees
aicraft breakup.

The news has flitted all over the place about each one of these as a cause du jour. They seem to now be feeding their readers on maintenance issues having to do with updating the pitot sensors.

For our continuing discussion which is a learning experience for all of us and especially myself, I have seen no direct cause/effect speed disagree to cause an accident without passing through pilot recognition and adherence to the FCOM.

As a flying community we need to take note that we operate in an imperfect world with imperfect products that are expected to be accomodated by knowledge, and training. So continue the technical what if discussions but don't leave out the expected response from the crew.

[massman]

I am a senior manager for one of the major mafcs. I read but don't contribute - partially because I can't but more because you are more the experts than I. However, I am going to make an effort to ensure that my company listens to, and acts on what is being posted here.

Maybe not everything is directly relevant to the thread but it helps, or should do.

Professionals or amateurs - keep up your good work. I honestly believe we have a common aim.

Thanks

[Capt.KAOS]

# 1 August 2005 - Malaysia Airlines Flight 124, a Boeing 777-2H6ER departed Perth, Western Australia for Kuala Lumpur. Climbing through 38,000 feet a faulty accelerometer caused the aircraft's ADIRU and autopilot to command changes of altitude. The flight crew overrode the system and manually returned to land the aircraft at Perth. The subsequent ATSB investigation led the US FAA to issue emergency airworthiness directive 2005-18-51 on the fly-by-wire software.[12]

# 6 August 2008 - The FAA issued airworthiness directive 2008-17-12 expanding on the requirements of the earlier AD 2003-26-03 which had been determined to be an insufficient remedy. In some cases it called for replacement of ADIRUs with newer models, but allowed 46 months from October 2008 to implement the directive.[13]

# 7 October 2008 - Qantas Airlines Flight 72, an Airbus A330 departed Singapore for Perth. Some time into the flight, while cruising at 37,000ft, a failure in the No.1 ADIRU led to the autopilot automatically disengaging followed by two sudden uncommanded pitch down manoeuvres, according to the Australian Transport Safety Bureau (ATSB). The accident injured up to 74 passengers and crew, ranging from minor to serious injuries. The aircraft was able to make an emergency landing without further injuries. The aircraft was equipped with a Northrop Grumman made ADIRS, which investigators sent to the manufacturer for further testing.[14][15]

# 15 January 2009 - The EASA issues Emergency Airworthiness Directive No 2009-0012-E to address the above A330 and A340 Northrop-Grumman ADIRU problem of incorrectly responding to a defective inertial reference.Air Data Inertial Reference Unit - Wikipedia, the free encyclopedia (http://en.wikipedia.org/wiki/Air_Data_Inertial_Reference_Unit)

[barrymung]

Safety concern, I realise MOST of the error messages are consistent with faulty speed indicators. What concerns me are those error messages that are unrelated to blocked pitots..what caused them?

[Safety Concerns]

well name them. TCAS is related so what other ones are you on about

[barrymung]

Safety Concern, you yourself said that at least one of the error messages was inconsistent with a blocked Pitot. There was also talk of a "faulty antenna" message, again inconsistent with a blocket pitot.

Can you see my cause for concern? I'm concerned as to what caused these "unrelated to blocked pitots" error messages.

[Dani]

my posting has been deleted, which I find highly unfortunate.

Let me rephrase:

It's highly unlikely that anything broke exact at the same moment when they entered a CB. Much more likelier is that first they entered the cells and then something happened.

The error messages on Acars are therefore not the cause, but the outcome of the accident. You will not find any information about the reason by looking into the technical details.

I have never experienced heavy icing (or even light) outside of clouds in the tropics. And never severe turbulences.

So it's pretty likely that they first entered into a storm system, then they experienced all the problems.

We should therefore concentrate on arguing about why the crew should have entered a thunderstorm system.

Dani

[WNcommuter]

BB said: I am saying the cause might well be something that unlikely: something nearly impossible, yet NOT impossible.AMF said: Basically, high altitude flying is potentially one of the biggest can of worms in aviation.....high altitude flying in severe weather quickly opens it, and nothing on the aircraft need be broken or malfunctioning for it to be perilous. (emphasis added)

Based on the discussion here by AMF and others, impassible weather is not uncommon in the ITCZ. This weather may have been impassible by any aircraft, especially a high and heavy one. If so, the most important question is "Why did the pilots fly through the weather rather than deviating around it?" The answer might be a nearly impossible combination of events or it might be something mundane and all too possible.

[Safety Concerns]

Can you see my cause for concern? I'm concerned as to what caused these "unrelated to blocked pitots" error messages.

NO

There was also talk of a "faulty antenna" message, again inconsistent with a blocket pitot

I have already explained that TCAS receives Air Data input and as such would log a failure if the ADIRU input was flagged. Please read previous posts.

From the maintenance manual, I hope its clear enough.

E.
Peripherals

The TCAS receives information from the following equipment :
(1)
Radio altimeter

(2)
Air data system

[galaxy flyer]

AMF

Could you recheck that link to the FAA publication-it is not working for me.
Ref post 363

GF

[max motor]

@barrymung

It's not unusual for aircraft to develop unrelated defects en-route. They may also be carrying deferred defects. There is no reason to assume that all reported defects MUST correlate.

Max

[funfly]

AMF
Thank you for answering some questions about flying at high altitudes that lie outside of the normal experiencies of us lesser pilots, and maybe that we didn't like to ask on this thread.

[Southernboy]

Possibly the weather & the ITCZ

[precept]

http://www.flightsafety.org/pdf/AP_UpsetRecovery/AP_Upset_Recovery_Supplement.pdf

[sumi]

In the last 3 years I experieced twice a black (inop) ISIS in the A319 during cruise, just displaying a error code and not resetable for the remaining of the flight. There were no other faults at all.

Communiqué No 11 of Air France (tonight 20:11 Local times) confirms that bodies now found. According latest post on Flight Int. 2 male and also a bag with an Air France ticket inside...

[mm43]

I noticed when searching the Brazilian Air Force website that they are using an 0214z position of 3 16 28N 30 22 28W which is at variance with the position that has previously been reported (3 34 40N 30 22 28W).

The Brazilian position is on track and 18NM south of the other, and they have stated that the recovered bodies etc. were found 69.5km (35NM) north-west of their 0214z position.

mm43

[CR2]

Tan, moderators are unpaid members of this site. We have lives and do not sit here watching every post "live". Sitting in many different time zones too. It's midnight in central europe right now, believe it or not the odd mod might just be asleep.

Perhaps (and I am NOT going to check), said post has been posted and deleted 5 times already - repetition.

I suggest everyone re-reads Danny's last post to close the previous AF thread. Give the R&N mods a break, ok? I don't mod here, just passing on a thought for you all.


EDIT: AHH. PPT, you got there first. Delete this if you wish.

[Mercenary Pilot]

Air France
Press release N° 12

Update on anemometric sensors

Paris, 06 June 2009 - 23:09 local time

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.

[p51guy]

WNC, Something must have distracted them from deviating. If they had been monitoring their radars and they were working properly they would have deviated. It is unlikely all the failures started before the turbulence of penetrating the cells because it is unlikely all the bad luck came at once. More than likely the turbulence caused the failures because of icing and power interuptions. Now that they have found some wreckage and passengers so maybe they can find the black boxes. I think Air France is hoping they are never found.

[BarbiesBoyfriend]

There is wx that will break ANY aircraft.

Wx like this existed that night and this aircraft was in it.

All this analysis of messages from the aircraft seems to be a matter of great interest to ppruners, but to what purpose?

I'm usually the last to agree with the 'lets wait for the investigation results' posters, but on this occasion I am with them 100%.

It was the weather that did it.

I hope they find the FDR and CVR because then we might find out why they flew into that awful wx.

Personally, I avoid it.

Edit to add: The main reason I am so keen to avoid is that one day I flew into a big 'ol Cb (probably 10% of the AF447 one) and got shaken ****less, but survived. Not pretty.:ooh:

[DC-ATE]

Dani -
So it's pretty likely that they first entered into a storm system, then they experienced all the problems.

Not sure there's enough information to conclude that.

We should therefore concentrate on arguing about why the crew should have entered a thunderstorm system.

The list of weather related aircraft accidents is way too long. There are still pilots who do not respect weather unfortunately. Guidlines are posted in all Flight Operations Manuals (or at least they should be !) on weather avoidance. When you are able to answer your question, "Why?", we will have made progress. Many pilots are "afraid" to carry extra fuel to avoid weather along their planned route because of fuel monitoring programs in place at some airlines. Others are 'management' pilots who think they're doing their company right by saving the fuel. Deviation fuel is cheap insurance.

[Mad (Flt) Scientist]

An interesting piece of info on the pitot probes indeed. My attention was caught by one particular sentence:

Should flight safety be concerned, the manufacturer, together with the authorities, issues a mandatory service bulletin followed by an airworthiness directive (AD).

That's not strictly true. It is the case that all Mandatory SBs (and ADs) arise from safety concerns. But I do not believe it to be the case that all flight safety issues automatically result in a mandatory SB or AD.

The Canadian Aviation Regulations, for example, state:

593.02 Unless the Minister considers that an alternative action to an airworthiness directive will ensure an equivalent level of safety, the Minister shall issue, in the form and manner set out in Chapter 593 of the Airworthiness Manual, an airworthiness directive in respect of an aeronautical product for which a type certificate has been issued, or accepted, by the Minister where

(a) an unsafe condition exists in the aeronautical product and the condition is likely to exist or develop in other aeronautical products;

(b) it has been found, subsequent to the issuance of the type certificate, that the aeronautical product does not conform to the requirements of the basis of certification for the type design of the aeronautical product;

(c) it is necessary to modify or cancel the requirements of an airworthiness directive issued by a civil aviation authority having jurisdiction over the type design of the aeronautical product because the Minister considers the airworthiness directive inappropriate for reasons related to the environment, safety, the delayed receipt of an instruction issued by a foreign civil aviation authority or reliance on foreign legislation; or

(d) it is necessary to modify or cancel a Canadian airworthiness directive that is in force, because a condition referred to in any of paragraphs (a) to (c) has changed or ceased to exist.
(my emphasis).

So if the OEM proposes a recommended SB, and believes (and convinces their authority) that the normal replacement cycle, or economic incentive to upgrade, or whatever, will get the parts changed out in time, then no AD is required.

It should be noted in that context that AF was sufficiently concerned to start the replacement of the pitots without needing an AD. Summary: the pitots may well have been a threat to flight safety, just people thought it was of low enough risk to carry the problem and address it without AD-level action.

edit to add that I have no reason to believe EASA are any different to TCCA in this regard, nor the FAA. I know of issues in fact where TCCA have issued an AD for their OEM, but EASA haven't required one for theirs. And I'm sure there are examples in fact of every combination possible)

[FlyingCroc]

The pencil pushers in their offices are part of this problem, every flight is different, the decision how much fuel is required is the discretion of the Captain. I don't think fuel was a problem on this flight, however there is a tendency in these Airbus planes to fly too high in the coffin corner.
I always try to prevent the FO's to request higher level too soon. They always push to get a higher level. :ugh:

[BarbiesBoyfriend]

The ever more rigorous application of strictly enforced SOPs, while in normal ops is a GOOD THING, can lead to trouble in abnormal ops.

It encourages new pilots to think that they are 'bulletproof' as long as the stick to the SOP.

Flying is a dangerous thing, made safe with much work.

There is NO substitute for experience and a great respect for ones own limitations, the aircrafts limitations and the weathers complete lack of limitations.

Be wary.

[protectthehornet]

you have great wisdom!

I've found 4000' below flightplan alt gives a nice buffet margin width...and not too much more fuel burn.

[WNcommuter]

DC-ATE wrote: Many pilots are "afraid" to carry extra fuel to avoid weather along their planned route because of fuel monitoring programs in place at some airlines. Others are 'management' pilots who think they're doing their company right by saving the fuel. Deviation fuel is cheap insurance.The reasons that pilots might or might not request extra fuel are speculative, so let's put that part aside for now.

If the crew had taken on extra fuel, it would be to AF's advantage to reveal that fact to illustrate that safety was paramount from the start of the flight. Yet unless all of us here missed it, AF has not said whether the crew requested and got deviation fuel. Therefore it appears to me more likely than not that the crew did not have extra fuel for deviation.

I really want to be proven wrong on this: I have several AF flights booked for this summer.

[DC-ATE]

As a Co-Pilot, I was fortunate most of the time to fly with Captains who were not worried about carrying extra fuel if they felt they needed it. They were the most comfortable to fly with. Some others I was able to convince to add fuel for various reasons. Some simply would not. Those I avoided. When I elected to fly Captain, naturally, I had all the fuel I wanted. Did I get called in the 'office' occasionally? Yes. I never changed my philosophy.

Whether or not fuel was an issue on this flight we do not know. The fuel load had not been made available yet I do not believe. It would be interesting to know how much 'extra' fuel was aboard. There again, flying too high might have been because of fuel issues. However, if you're too heavy, you're going to burn more than you save just trying to get up and maintain the higher altitude. Maybe it's time to institute a 'fuel surcharge' and divide the cost of an extra thirty minutes fuel among the passengers. I'm sure they wouldn't mind.

[lomapaseo]

I've got to admit that I'm confused about the strong opinions being expressed about the crews decision to fly into a thunderstorm.

I have to ask myself what did the crew know and when did they know it?

And just how do the posters decribe and define a thunderstorm relative to a 3 dimensional module?

I never thought that it was possible to set a tract that would avoid all storm fronts by 100 miles or so, but instead to set an altitude and tract to avoid the most dangerous part of the storm. So to me the mere fact that some turbulence and lightning are reported does not convince me at this time that the crew acted carelessly.

[Locked door]

Fuel would not have been an issue. Period.

No sane aviator would penetrate a CB just because they might not reach the destination with div+reserves or even reserves.

If a fuel shortfall is identified you burn as much of it as you need to to avoid weather enroute and replan a closer destination for a tech stop. On the route in question Faro or Lisbon are ideal, in extremis the Canaries are closer.

[CR2]

DC-ATE, have you seen the price of a ticket recently (or a ton of cargo for that matter?) The fuel surcharges equal or exceed the "cost" as is..... It is how our dear industry manages to make $ from time to time.

[Carnage Matey!]

Where has the idea that they didn't have enough fuel, or should have loaded more, appeared from? If they took extra fuel great. If they didn't they could have deviated around the weather and dealt with the shortfall later, like any professional aircrew would. I've found myself weaving around thunderstorms in the company of Air France in another region of the world and they were many miles further off track than we were without too much concern. If that is representative of corporate practice, and I've no reason to doubt it is, then we can put the fuel concerns to bed.

[protectthehornet]

perhaps the best available information to the crew lead them to the route they followed. much has been written about the shortcomings of even the most modern of wx radar.

I think, until a CVR recorder is found, that we should assume the pilots followed a reasonable course of action based on the information they had.

[Captain Airclues]

WNcommuter

There is no such thing as 'deviation fuel'. All aircraft carry 'contingency fuel' which is intended to cover weather deviations amongst other things.

Dave

[protectthehornet]

I think we all fly in different worlds of flying...in my world we have contingency fuel for the unknown

we have fuel to destination

we have fuel to alternate

we have fuel for holding

so...let us all learn from each other

[aussiepax]

For the non-pilots who have an interest in this;

It's hard to explain to the uninitiated just how differently an aircraft flies when near the top of it's operating envelope compared to just a few thousand feet lower, and what these degradations and thin margins mean. If you're near the top end of that envelope, even something as little as a unforecast, sudden rise in temperatures aloft of 5 to 10 degrees can require immediate action (descent to a lower altitude because engine thrust isn't available in excess at altitude) because the top of the envelope is lowering...crashing down if the temp rise is quick enough.

Thanks AMF. For SLF such as me , this discussion is a fascinating eye-opener regarding the rationale behind these various parameters of high altitude, temperature change, weight, thrust ,AOA etc.

[4PW's]

On why this occurred: Coffin corner, mixed with severe weather.

On fuel: 3 hours into the flight, more than enough contingency to deviate.

On Cb penetration: Unknown. Worrying.

On this thread: Valuable.

[Mad (Flt) Scientist]

What does this mean "coffin corner".
At any altitude, if you go too slow, you stall - loss of control.
At any altitude, if you go too fast either you run into flutter (very bad) or hit high Mach effects such as buffet.

So the operational range must lie between the two limiting speeds.

The two speeds get closer together, the higher you go, until eventually they meet.

At that point (called "coffin corner"), if you slow down, you stall, and if you speed up you get nasty Mach effects. Proverbial rock and hard place situation.

[Junkers388L]

TCAS is fed air data information from the ADIRU's. If you already have faults or issues with the ADR part the data bus going to TCAS will log a fault.

Once again 23 of the 24 messages can be traced back to air data.

That's entirely plausible (see my first post in this thread). But we have to be very careful not to jump to the obvious conclusion in this case without additional verification.

Regarding the timely sequence of the error messages, what puzzles me is that both the pitot probe and TCAS-related events have a 02:10 timestamp, whereas the ADR disagree event is 02:12, roughly one minute after the IR2 failure.
That is why I was wondering before how specific the TCAS error code in the ACARS message actually was, and whether other sources of TCAS error can safely be excluded.

[wheelie my boeing]

As Mad Scientist said; if you slow down you stall and if you speed up you overspeed (running into buffet etc). The heavier you are and the higher you are the closer the two limits. So if you have just taken off with a large amount of fuel and you climb to your max operating altitude, "coffin corner" could be quite small. I have been in a situation where if I slowed down by 7/8 knots we would be in essence about to enter a stall - and if we sped up by 7/8 knots we would overspeed. I kept a VERY close eye on the speed! After an hour or two we had used a fair amount of fuel and so our weight was lower - now we had (I forget exactly) 14 knots from the stall and 14 knots from overspeed...

[FIRESYSOK]

Some have speculated that something must have been wrong before the weather penatration for the crew to continue through the area. As said before it may not have been a bad course to take with the information available. With a loss or discrepency in airspeed indications, manual flight, the situation could go pear-shaped in a matter of minutes or less. If the ISIS was also affected this is a grave scenario especially in poor weather and nighttime. It would be beyond the capability of most of us I belive.

[4PW's]

As altitude is gained, the air thins. Try breathing on top of Mt Everest.

As the air thins, the speed at which an airplane will stall INCREASES. At the same time, the speed at which an airplane enters the supersonic realm DECREASES.

Imagine a vertical bar chart. Up, down, right? Go ahead and draw one on a piece of paper right now. It will be a lot easier if you have a picture. The drawing does not need to be pretty.

Now graduate the vertical bar you've drawn with horizontal marks. These marks, or ticks, are the airspeed. The unit of measurement is the knot.

At the top of the bar chart, color the ticks in red. Make these ticks, or graduations if you like, thicker than the others. The red ticks represent a high speed "no-go" zone for the airplane. Flying in the high speed red bits at the top of the bar chart reduces overspeed protection. The airplane is now approaching the supersonic realm.

At the bottom of the bar chart, color the ticks in red. Make them thick, just like the red ticks at the top of the bar chart. The red stuff down here is the low speed stall area. Fly in it, that is, reduce your airspeed enough, and your airplane will fall out of the sky.

Now, as your airplane climbs ever higher into thinner air, the red at the top of the bar chart comes down. You don't have to draw this. The flight instruments in a real airplane show the red ticks coming down. At the same time, the red at the bottom of the bar chart rises.

At some point the red bits will be so close that the airplane cannot slow down by a knot, nor can it increase by a knot. Doing so would see the airplane stall on the one hand, or overspeed on the other. The airplane now has no 'manoeuvre margin'. None at all. This is what we refer to as 'coffin corner'.

No pilot will knowingly fly his airplane (masculine encompassing the feminine) in 'coffin corner'.

In another type of graph used to depict reducing manoeuvre margins for flight due to increasing altitude, the presentation is of an upside down V-shape. Each side of the upside down V-shape represents airspeed. On the left is the low airspeed stall. On the right is the overspeed 'speed'.

At low altitudes, the upside down V-shape is wide. There is a wide manoeuvre margin. At high altitudes, the upside down V-shape is thin. Here, there is a thin manouevre margin. Coffin corner is at the top of the upside down V-shape.

I hope that helps.

[HarryMann]

If the theory of a strong thermal updraft pushing the aircraft out of its operating envelope does turn out to be the case, and with all the flights that routinely travel this route, does this mean the cause is just bad luck, being in the wrong place at the wrong time at the wrong altitude at the wrong weight?As the saying goes- 'it's one theory' (that daserves consideration)

That's not a very comforting thought. Why would a flight be on the knife edge knowing it was heading into a situation where greater margins could potentially be called for?That is another question altogether... and reading back a few pages, several commentators have pointed out that if so, that is the pre-eminent question!

One answer that has occurred to me, and I think deserves knocking down quickly, is that the possibility of overflying the worst might have seemed a 'least worst option'

Another, that whilst potentially safer lower down as far as maneouvre margins are concerned (& thus actual 'upset'), roughness of ride and high airframe loads can likely be more guaranteed and last longer (transit time)

[DC-ATE]

One answer that has occurred to me, and I think deserves knocking down quickly, is that the possibility of overflying the worst might have seemed a 'least worst option'

Another, that whilst potentially safer lower down as far as maneouvre margins are concerned (& thus actual 'upset'), roughness of ride and high airframe loads can likely be more guaranteed and last longer (transit time)

Both are possibilities. That is why it is imperative to AVOID these areas.

[Flyinheavy]

Well, I do not think that they were speculating on anything like 'overflying' given the fact, that the tropopause was marked at FL450 in that area and tops of embd CBs at FL480.

Seeing that WX Chart me too I would not have been especially alerted.

By the way, LH507 and LH-Cargo were passing the area without any problems. LH503 30 min bef AF on the same AWY without reporting anything about turbulence or icing.

[Flyinheavy]

@DC-ATE:

All I wanted to say with this is, that I do not speculate that they would be thinking of overflying the weather. I personally do have a very good impression of french aviators, I know about their trainingstandarts ab inicio. I have problems to imagine that they got caught in that situation by their own fault.

The rest has to be shown by the investigation.

[Flyinheavy]

@HarryMann:

I have been reading it, by the way both editions. All I can say is, that I crossed the ITCZ to/from Brazil, I do have to look in my logs how many times. Did so in Africa as well. I do not want to downplay nothing that had been analysed by Tim, excellent analysis. But still, how many planes were lost in the last decades on the South Atlantic?

There must have been various things coming together for this unlucky flight.

[DC-ATE]

Speculating on PPRuNe -

I would like to insert this here before we see another:

"This thread is now closed. The main reason being one of too many uninformed speculators relying on unattributed media quotes..."

All over the World since AF 447 was reported overdue/lost, professional pilots in their cockpits have been 'speculating' on what happened that fateful night over the South Atlantic. To suggest that they are only relying on 'facts' is absurd. That's what pilots do: speculate on what happened on every incident/accident. When the final reports come out, they will even speculate on the validity of some of them.

As the title "PPRuNe" suggests: RUMOUR. The only thing different is this Forum contains posting by other than Professional Pilots. But I don't think it's possible to prevent that. Besides, there ARE many good posts by other than pilots that do contribute to not only the RUMOURS, but speculation as well. All of this information is needed by those who attend these forums to try and make some sense of what might have happened, not only in this case, but others as well. All of us are "uninformed" at this state.

[4PW's]

Blame is starting to creep into the thread. It didn't take long. Someone started writing how pilots don't know how to use the weather radar. Now we're getting accusations of trying to fly over the weather, and that there are so many pilots nowadays who "don't know anything about high altitude flying". I'm not so sure about that.

My wife is not a pilot. Nor are her family pilots. None of her in-laws, their children or our children are pilots. Some of the relo's are heading off tomorrow for 'wherever'. They are suddenly unsure of what it is I do, as if they ever knew. AF447 is the conversation no-one is having. They're too damn scared to even think about it. So I think I can see this from the perspective of non-pilots reading this thread.

Most are uncomfortable with flying, period, and often ask "what carrier should I avoid" in the hope of not falling out of the sky at night over a foreign shore or sea. And when tragedies occur such as with AF447, the easiest answer to fill the dreaded hole of naivete about how pilots fly airplanes is that pilots don't know how their airplanes fly; don't know what they are doing; don't know how to use a weather radar; don't know about high altitude flight; don't appreciate that contingency fuel ("er, what's that?") is for contingencies, oddly enough; don't know that if you ... and so on and so on.

Often times, events occur that are above the experience level of the men and women on the job at the time. It would appear this is what happened, else the airplane would not be lost. Flying is inherently dangerous. The environment in which flight occurs demands respect, as anyone who has ever been near a giant Cb well knows. Aviation demands attention to detail. There is nothing, not a shred of evidence, to show our fallen colleagues operating AF447 were not aware of these intrinsic facts of flight.

[Will Fraser]

What I am left with after reading the entire thread is just a bit more about the Airbus and also it's mfg. and it's owners.

The idea is to build and fly an a/c that "protects" itself from stall, excessive amounts of roll, pitch and a/s, programmed uniformly into a computer that virtually 'covers all the bases', prevents ham fisted pilots from over eager input, until..... it can't. Then the potentially abusive pilot gets the whole enchilada in his lap, with some stab trim and a restricted rudder. A hemmorrhage of electric data is broadcast after the fact, but can't be relied on because it results from, doesn't cause, the faults that the airline hope are never discovered. That about it?

[WNcommuter]

It's not about blame. It's about exploring all possible contributing factors and eliminating them in the future, whether those factors were present in this particular accident or not.

For example, if some pilots believe that a modern aircraft can transit any CB, and if that's not the case, then this discussion would be valuable just to highlight that problem. Again, regardless of whether that problem turns out to relate to AF447.

[Thermal Rider]

A detailed description of the ACARS warnings and fault reports can now be found on the AF 447 wikipedia page. It captures the information shared in this forum and additional information from the A 330 systems and operating handbook. Maybe people with direct access to all ACARS codes can refine the posting. More detailed observations from operators concerning the pressure system and on disengagement of auto-thrust could also add to the accuracy of the section.

[mseyfang]

A question for long haul Airbus pilots:

While I make no claims to be an expert on ETOPS fuel reserves, I do know that there is an ETOPS fuel requirement to carry sufficient fuel for high fuel burn situations, such as an enroute pressurization failure necessitating a descent to a breathable altitude. Given this, and the availability of alternate airports (the flight would have passed close to or over the Cape Verde Islands and Tenerife) along the planned route for a tech stop, my question is whether these factors more or less ensure that there was sufficient fuel for a weather deviation. In other words, it seems to me that the failure to make a course deviation was not likely caused by fuel issues. It seems to me there would have been enough fuel to deviate and still cope with a subsequent problem since Cape Verde was approximately 750 nm away. I don't have the tech data to work through the math myself.

Or, am I missing something here?

[DingerX]

The Air France Press Release #12 cited by Mercenary Pilot in currently post #397 and available directly (http://alphasite.airfrance.com/s01/?L=1) has some interesting points, most notably number 2:
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.

This means:
A. Air France has had a significant number of A330/340 pitot probe icing events in the past year, and presumably has a very good idea of the sequence of ACARS messages that they generate. Do the ACARS messages generated by AF447 look anything like the ones in AF's possession from prior cases of pitot probe icing? What about other carriers?
B. Air France's solution to this problem was to adopt fleetwide the probes developed to solve water ingress problems on the A320 before they could be evaluated outside the laboratory, and in spite of the manufacturer's claim that the design was not made to address this problem. So, even if the 'A320 probe' was fitted to AF447, there's no guarantee it would have done something.
C. The OEM's proposed 'solution' to pitot icing, reiterated by the operator, was/is to follow the procedures outlined for unreliable airspeed.

---
I'll let you folks do the speculation.

[Captain-Crunch]

Will Fraser said:
What I am left with after reading the entire thread is just a bit more about the Airbus and also it's mfg. and it's owners.

The idea is to build and fly an a/c that "protects" itself from stall, excessive amounts of roll, pitch and a/s, programmed uniformly into a computer that virtually 'covers all the bases', prevents ham fisted pilots from over eager input, until..... it can't. Then the potentially abusive pilot gets the whole enchilada in his lap, with some stab trim and a restricted rudder. A hemmorrhage of electric data is broadcast after the fact, but can't be relied on because it results from, doesn't cause, the faults that the airline hope are never discovered. That about it?


Mr Fraser,

Yours is the best post of the entire thread. Although you were probably trying to highlight the irony, you have deftly hit the nail of the problem on the head. I now promote you to Chief Pilot of Airbus Industries, since it is clear from your honesty, that you not only fathom more about the problem than anyone else in the world, but that you have no vested interest in denying the unenviable situation that all great "Pushbutton-Pilots of Tomorrow" now face.

Which is the dilemma:
Concur with the Airbus Religion of Total Obedience and preference to Automation approved by government and business, or be burned at the airline stake as a heretic. (Translation: Never Hand-Fly, or else!)

The tyranny of SOP's assumes that everybody has the same currency retention skills and will never need line hand flying skills anyway since the Airbus was marketed to the third world as "an airplane that virtually flys itself" (that doen't really need pilots or a PIC, wink, wink)

But the real world truth is: that as the automated world fleet gets older, this sort of accident is going to happen more and more. You can't have the PIC (pilot in command) be behind a desk in France issuing edicts in a Ivory Tower. The PIC must be empowered in the airplane to conduct line training as he sees fit. "The PIC must be the FINAL authority as to the operation of that aircraft." - FAR, and axiom held sacred for every ship commander throughout history. This includes a duty to train new co-pilots in the art of hand flying on legs where you don't need to be a slave to the FMS.

Crunch - Out

"You can only have one Captain of the Ship" -author unknown

[vapilot2004]

@Avspook

Thank you for the ISIS info.

I am aware of the previous iterations of the A330's standby instruments, shared by my own aircraft (737, MD-80) but the ISIS arrangement is revelatory to a comparatively moldy-oldie driver like me.

[vapilot2004]

@Windsheer: As I have just been schooled on this....

The current A330 models have an electronic system that uses independent sensors for altitude and airpseed via the pressure pipes (assuming #2 or #3) already brought into the aircraft. Sharing pipes is a common practice.

The ADI or artificial horizon is a self-contained l a s e r ring gyro.

Previous A330's (and A320 series) used the classic arrangement of the altitude & airspeed provided by actual needle pointing pressure actuated gauges, while still using the shared piping arrangement and the ADI being an electric gyro.

In both cases, we also have a compass, lit by electricity internally or flashlight if need be...

[slamer.]

Hmmmm....is this starting to sound more and more like the Perpignan A320 accident back in Nov...?

[Dysag]

The ETOPs minimum fuel requirements you describe are mainly to ensure sufficient fuel is carried to divert to the en-route alternate at 10000ft and with one engine inop. This calculation is compared to the normal fuel needed to see if extra has to be loaded.

The ETOPs minimum fuel calc normally only requires extra fuel if the distance to the en-route alternate is very long: consistent with a 180-minutes from alternate rule.

While AF447 was an ETOPs flight, it was not planned to ever be more than 120 mins from an alternate and it's highly unlikely that extra fuel was needed to satisfy ETOPS requirements.

I don't believe for a moment that the failure to deviate around the wx was fuel related.

[Airbrake]

PJ2.

The Airbus family are easy to fly because.....the computers fly them. As pilots we simply point them where we want to go a then can literally let go of the stick as the computers auto trim out thrust changes, config changes and speed changes. I have no doubt my manual flying skills have declined since conversion on to type, we even leave the auto throttle in until it tells us to "Retard" no thinking required.

Airbus automatics make hamfisted pilots look good. If Airbus developed a Cessna 152 that had auto trim and auto thrust the PPL could be reduced to a 5 hour course because no pilot would actually have to know how to fly an aeroplane.

Modern automation on the flight deck severely erodes basic flying skills. I truly hope this wasn't a factor in the loss of the AF A330.

[TonyWilliams]

Airbus takes control away from the pilots.

Yet pilots are still the number one cause of aircraft accidents.

To all things, a balancing act.

[Celestar]

ETOPS fuel is often required when the ETOPS zone is at the end of your flight, no need to develop further as it will be anyway deleted. I can’t imagine that fuel saving was an issue for AF447’captain.

[cartmans lovechild]

well said Tony.

The automatics make life easier but the failure states on a BUS are far more complicated and less intuitive than on a Boeing.

Going back to stick and rudded as the 'cure all' is naive at best.

better training (not the cheapest) more redundancy (not necessarily the most modern systems) and mandatory loft training for pilots based on ACTUAL fatal event like this and how to cope should be the minimum going forward.

having flown most of the big manufacturers I'd still prefer the BUS for failures like EFATO and approach failures and day to day ops - but the Boeing for crosswinds, turbulence and 'significant multiple failures.

At 2 in the morning at that altitude, in that weather faced with a rapid sequence of failures (if thats what happened) i'm not sure how any aircraft would have come out of it better. luck aswell as skill has a disproportionate influence.

[PBY]

Hi guys, I am an airbus captain with about 3000 hours on type. I have never been tought unusual attitude recovery in the sim. I was told, that you don't have to have this training, because the airbus has so many protections, that you don't need this skill (sounds very similar about the reasoning behind Titanic, but lets forget about this).
Are you, Boeing guys, tought unusual attitude recovery from upsets in the sims?

[barrymung]

I agree.

In a lot of respects a more "hands on" type of plane is better, not least that the pilot actually has to fly the thing!

However, you can't stand in the way of progress and increased automation is the way it will go..

Whilst it's conceivable that "fly by wire" automation *may* have contributed to this accident, how many crashes has it prevented in the past? How many planes would have crashed were it not for the 'puter saying "You ca n't do that, mate"..?

[barrymah]

Quote from the head of the French met office -

"If you look at the three or four days surrounding the accident, there was more intense development before and after than on the night of the flight itself," he says, adding that at 02:15UTC the growth phase of the local cumulonimbus had already passed and the clouds were in the "lower end" of their cycle.

"We cannot conclude that this situation was exceptional," he says. "There was no unusual intensity or strength."

Bye, Barry

[1sloth]

Are you, Boeing guys, tought unusual attitude recovery from upsets in the sims?

Yes :ok:
.

[747JJ]

On all the Boeing type rating courses I did, we went through unusual attitudes and recovery. This was not part of the Airbus Toulouse curriculum as I recall, but the instructor I had offered a good set of unusual attitudes in direct law.

[falconer1]

"we can't say there was anything exceptional".. ( in regards to weather)

empty & stupid statement..

You do not need any "exceptional convective activity" for any CB to be a danger to any airplane..

[barrymah]

'empty and stupid' - if taken out of context; he said -

"We cannot conclude that this situation was exceptional," he says. "There was no unusual intensity or strength."

As the head of a met offcie one has to assume he knows about usual and unusual in the context of weather.

OTOH, he is only looking at the data after the event; it is always probable that the momentary situation was different.

As has been said many times on this thread and other related threads, we are in a low/no information zone; the comment on the met situation is at least based on an analysis of the situation at the time and place.

Bye, Barry

[Wytnucls]

It seems more and more likely that the AF crew on that fateful night were routinely picking their way around CB cells in the ITCZ, like all airline pilots do on a regular basis, when they unknowingly flew through an air mass that contained enough ice particles to disable all pitot probes.
The resulting effects of such failure at high altitude, as documented earlier in the thread, are quite dramatic on the flight instruments and may have led to a rapid loss of control of the aeroplane.
Since the crew primary task then, is to try to regain control before anything else gets done, it is not surprising that distress calls were never made.

[setandcontact]

4PW's - spot on.

Slammer - good point but I would caution a no to that. Maybe the only similarity is airbus?

[Interflug]

Question:
What happens if the weight (ZFW) entered in the FMC is lower than the actual weight of the airplane? Wouldn't there be a difference then between real and calculated "coffin corner"? (I'm not a pilot)

[YoDawg]

Two bodies and more debris found by searchers:


Brazil's air force recovered two bodies and debris from an Air France jetliner that came down over the Atlantic on June 1 with 228 people on board, a spokesman said.

"We confirm the recovery from the water debris and bodies from the Air France plane," Colonel Jorge Amaral told reporters in the northeastern city of Recife.

He said the two bodies, the first recovered from the downed flight, were those of men.

A plane seat, a nylon backpack containing a computer and a leather briefcase with an Air France ticket inside were the first objects plucked from the sea, he said.

The discovery took place 450km northeast of Brazil's Atlantic archipelago of Fernando de Noronha, itself 370km from the mainland.

Amaral said the blue plane seat has a serial number on it and Air France is checking to confirm that it came from its downed flight 447, which was travelling from Rio de Janeiro to Paris last Monday.

Amaral said the seat was the first item recovered.

The first body was then sighted by a navy vessel and was recovered 20 minuted later by the ship's crew.

The last item recovered so far was the backpack, he said.

[dessas]

You will end up immediately with a big discrepancy in the fuel required on INIT2 page and dest fuel on FLT PLAN page compared to your SITA figures.
:bored:

[TyroPicard]

@Safety Concerns
Once again 23 of the 24 messages can be traced back to air data.I must be a bit slow - can you please explain how air data disagreement can lead to the IR portion of the ADIRU failing? The ADR can be switched off leaving the IR running - but not vice versa.
Thanks, TP

[TyroPicard]

airpolice
That cannot happen - needs power supply, connection to aerials etc.
If I were you I would ease up on the Strongbow...

[Interflug]

Thank you.
Does the A330 have the option to weigh itself and does Air France have this option?

If yes, which max. difference between calculated and measured would be acceptable for dispatch?

This max. weight difference would theoretically translate to how much difference in the max. altitude the airplane can fly?

[ILS26L]

How probable would it be that the A330 had a "minor" techical fault, spotted on the ground in GIG, before the aircraft left for CDG, but after pressure put by AF ops on the captain, insisted he returned to CDG to have it sorted there? And then, a lightening strike or adverse weather conditions made the problem worse...?
Does AF have engineers at Rio or would they have had to fly someone out, thus delaying the arrival of the Aircraft in Paris, which most probably was going to fly somewhere else after?
Is AirFrance Ops worrying now that this could leak out and are wondering who to point the finger at?

[dougydog]

1. Have the radar turned on- sounds wierd but I`ve seen a few folk fly along with terrain on instead of weather.

2. Deviate early enough(90% of the time the CBs are above you in the tropics especially)then you don`t tend to increase the track miles by much and ergo you don`t burn too much extra fuel either....So fuel shouldn`t be an issue. If you take the gamble to `look` at the storm first by flying up to it you will have more track miles to cover to deviate around it...

3. Often the return on the weather radar will `disappear` the nearer you get to the CB..Are you above it, or not? Or is your weather radar not picking up the ice near the top of the cell. You have to play with the tilt...On really dark, moonless nights I remember the distance from the cell to the next waypoint and if I deviate I know not to turn back until I`m well inside that distance incase the return does the `disappearing act`.

Questions; That last acars msg....cabin vertical speed...Does it mean the cabin is going to `over take` the outside ie airplane in a dive or does it mean decompression??

...Interesting that "male bodies" have been found....Could they have fallen out of a breakking up aeroplane or does it mean that the impact was less severe??


Some great discussion on here keep it up folks!!

[mickk]

Since the crew primary task then, is to try to regain control before anything else gets done, it is not surprising that distress calls were never made.

If situations can arise then, where using the radio to call a mayday is not possible due to the work load in the cabin, then its time voice activated radio was introduced, if not one simple button to send a distress message.

To not be able to transmit in an emergency situation is a serious flaw that needs to be corrected.

[Erik.G]

Some photages of the debris found

http://gfx.aftonbladet-cdn.se/multimedia/dynamic/00947/vrak2_947032l.jpg

http://gfx.aftonbladet-cdn.se/multimedia/dynamic/00947/vrak_947033b.jpg

[avspook]

@slamer.

As mentioned in my previous post. THE AOA's bother me in the fact that the Perpignan A320 SEEMED to have frozen with No Crew warning.
Icing of the aircraft in this thread would surely mean the AOA's subject to the same icing conditions & again IF they Froze with No crew warning that takes part of the Crew instrument assistance away.

[mixture]

.... if not one simple button to send a distress message.

To not be able to transmit in an emergency situation is a serious flaw that needs to be corrected.


Oh mickk.....

What is your aviation background ?

If a pilot of some sort, did none of your instructors teach you A . N . C . ?

:ugh::ugh::ugh:

In a complex aircraft such as a Boeing or Airbus, are already sufficient alarms and annunciators to deal with. I would like to think that all line pilots are perfectly capable of making a mayday call by the traditional means where cirumstances permit.

[Cacophonix]

To not be able to transmit in an emergency situation is a serious flaw that needs to be corrected.


If the Air France pilots were so maxed out by the situation they were in (and this is just supposition) then what value would have come from a radio transmission from them? They probably wouldn't have had the physical and mental bandwidth to communicate any useful information.

In a sudden and extreme situation it it is likely they would have been trying to disambiguate multiple readings, warnings and symptoms.

As it stands, we don't know whether they attempted any transmissions on HF.

[NoseGear]

As an Airbus A330/340 pilot, theres a few questions on here Id like to answer:

Interflug, when any airplane is built, the weight is calculated by the design engineers as weight is one of the biggest enemys, if you like, of aircraft, in that, the heavier they are, the more fuel they burn etc etc. When the aircraft is built, they are weighed, and in the aircraft we have a revenue and a training weight index. Revenue includes everything, crew, catering, the works. Baggage and cargo are loaded and we then have our ZFW, which is sent to us by dispatch, and which we double check on our loadsheet. We also know how much fuel is on board, in our airline, we are given the fuel in Litres, multiply this by the Specific Gravity to calculate the weight in KGs, we add that to our ZFW and that is the aircraft Gross Weight. You are correct in that this will decide our max alts. There is no discprepancy allowed with the weight.

ILS26L....highly unlikely, we fly to probably a hundred destinations, and we have engineers at every port. Usual practice is to contract out the home ports airline engineers that are rated on type, and train them up on your airlines procedures etc. I cant think of a "minor" fault that would lead to this.

dougydog, the 'Cabin Vert Speed" message on the ACARS was probably because the vertical speed was above 1800ft/min, which doesnt cause an ECAM msg, the value pulsates on the System Display...the ECAM warning pops up when the Cabin Alt is above 9550ft. The masks drop at approx 14000ft. Cabin Alt.

[one post only!]

mickk, ask yourself what help would a mayday call really bring in this instance? None. What help would focussing all your efforts on the problem in hand give you? It might keep you alive!

If you are late downwind and burst into flames a quick call to ATC that you are turning finals immediately will bring immediate help. In the middle of the atlantic faced with an catastrophic situation what help will a radio call provide???

Its all about priorities.

[Safety Concerns]

@tyropicard

One of the problems of not reading all the posts is you miss things (post 376)

The only message that it wouldn't cover is the IR2. hence only 23 of the 24

[avspook]

@Question_Answer

The WXR as fitted to modern aircraft should be sufficient.
However remember its purpose, weather avoidance NOT weather penetration.
I have seen a P3 Orion with a significantly better output power and resolution RTB with major hail damage as the Radar Picture was misinterprated.

[Safety Concerns]

spot on Captain Crunch and with so many messages related to one item its not coincidence.

If you received any messages at all from an aircraft that was in the process of breaking up they would most likely be completely random. These AF 447 messages are not random but they are also not conclusive evidence of what exactly happened.

I suspect over time though they will become extremely relevant.

[avspook]

Working sytems required for ACARS Transmission

ACARS Management Unit
Satellite Data Unit
Beam Steering Unit
Antennae
Power supplies
Faulted Reporting System.

These Reports Can be generated in milliseconds The aircraft has not traveled very far in space between the warning & the data transmission
Do Not look at just what Has failed on these report look at what has Not,

[Celestar]

And without those ACARS messages, where would the SAR, investigation, rumours and theories be? Even if it's not the main purpose of those maintenance messages, it's a definitive improvement in crash rescue and investigation for sure, especially without CVR and FDR, and even no plane at all.

[DC-ATE]

TonyWilliams -
Quote:
Airbus takes control away from the pilots.
Yet pilots are still the number one cause of aircraft accidents.
To all things, a balancing act.

Unfortunately, you're absolutely right. And the fact that in most cases the pilot is not there to explain what went wrong, makes it even worse. It's left to investigators to "speculate", in many cases, what happened. There have also been "cover-ups" in accident investigations where the crew was unable to defend themselves as well.

We've come a long way, but still have a long way to go.

[petermcleland]

Quote:-

"Regarding pitot/static - surely a "safe" design for any modern aircraft is based on the knowledge and operation from many decades of aircraft design, so if this variant of aircraft has an inherent design flaw in this area it does surprise me."


Another Quote from Air France:-

"Without waiting for the in service evaluation, Air France decided to replace all its probes and the programme was launched on 27 April 2009."

Probably the second quote answers the first quote...There must have been inherent design flaws in the existing probes for Air France to launch into replacing them all...If not then you could say "If it ain't broke then don't fix it".

[Interflug]

by NoseGear
Interflug, when any airplane is built, the weight is calculated by the design engineers as weight is one of the biggest enemys, if you like, of aircraft, in that, the heavier they are, the more fuel they burn etc etc. ...There is no discrepancy allowed with the weight.Thank you for taking the time. I do know all this. My question is more, that you as a pilot have no way of verifying, if a weight on a load sheet is correct or not, is that so? I'm interested to learn. If someone screwed up with the cargo weight for what ever reason and you have a wrong number on the load sheet, when is the moment you will find out?

Could that theoretically be at least a contributing factor for being too high too early in the flight, without margins for sudden temperature changes or turbulences?

[Pontius Navigator]

barry, unless the possible position of the surface fires is within the debris drift area then it is a non-starter.

[hellsbrink]

Bear in mind that it has been reported that witnesses saw a "bright flash" and around 6 or so falling chunks of burning debris.



Wrong, wrong, wrong and wrong!

The initial El Mundo report said how the "witnesses" saw a bright flash which dissipated after 6 seconds, not 6 distinct objects falling. What you are talking about was not only poor reporting by The Age but also, at least, a mistranslation.

Also, these "witnesses" on the Air Comet flight (the one the two people who claim to have seen this flash were on) were over 2000km away. Now, are you saying that human eyesight is able to not only see an aircraft at that distance but could also see individual parts falling, especially since the suggestion is that AF447 was actually in a rather large cloud at the time?

[navtrack]

Refer to a note TFU (Technical Follow Up) from Airbus TFU Ref 34.13.00.005 first issued Nov 1995 :

" Operators have reported airspeed discrepancies while flying under heavy precipitations or freezing conditions, which sometimes led to the autothrottle and the autopilot disconnection, THE E/W "F/CTL ADR DISAGREE" AND "F/CTL ALTN LAW"........

Strong Cumulonimbus containing a high density of ice crystals can be encountered, particularly in the intertropical convergence zone (ITCZ).

In such icy and turbulent atmosphere, the Aircraft Air Data parameters (Pressure Dependant) may be severely degraded, even though the probe heaters work properly.

It has appeared that the characteristics of such an environment could exceed the weather specifications for which the pitot probes are currently certified. "

Referring to AFP (Agence France Presse) article reproduced below, Air France A330 and A340 had previously encountered problem in flight with the anemometric system. The replacement of all Pitot Probe ot AF Airbus's fleet following recommendation edited by Airbus in September 2007 was launched since April 27, 2009. Unfortunately, the pitot probe of A330, F-GZCP involved in the accident was not changed yet.

One of the 24 ACARS messages sent by the airplane was EFCS PROBE 1+2/2+3/1+3 specifying so that all probes was in default.

With all the above, it would be difficult to any pilot to fly an airplane without exceeding the limit of what it was certified. Specially in bad weather.

Question : The problem was known since 1995. Why such long time for correcting the default ?




Paris, 06 June 2009 - 23:09 local time

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.

[NoseGear]

I see what you mean, no, we would not know that the weight is out...and as to when we would find out, maybe during flight, maybe never! I dont know what the weight of the accident aircraft was, but I doubt that flying close to our Vmo or Green Dot was causal. If Im going to be picking my way thru heavy weather, I would consider delaying a step climb or stay a level lower to give myself a bigger margin over high and low speed limits. What the AF crew did remains to be seen, but I doubt that they were pushing any altitude limits.

As for "Airbus takes control away from the pilots"....not true. There is simply a limit as to what you can do TO the airplane, ie, it limits the amount of G you can pull, the speeds and attitudes you can go past etc. If the poster is implying that somehow a limitation on the pilot did not allow him/her to recover from an unusual attitude, then that is also incorrect.

[DingerX]

Barry: It seems extremely likely that the two incidents were unconnected.
In a catastrophic event like this, with such a void of information and a need for it, even the smallest noise can be amplified.
Were these "floating fires" reported at the time, or after the flight was known to be missing? Were the witnesses absolutely certain about the number, size and nature of these "fires", or was the information rather given couched in the terms of, "I doubt this will help, but for what it's worth, we thought we saw..."
The only explanations that fit all solid and putative data points are conspiracy theories. The real world is noisy.

And what's the point of analysis if you insist on taking information at face value?

[Captain-Crunch]

avspook said:

Working sytems required for ACARS Transmission

ACARS Management Unit
Satellite Data Unit
Beam Steering Unit
Antennae
Power supplies
Faulted Reporting System.

These Reports Can be generated in milliseconds The aircraft has not traveled very far in space between the warning & the data transmission
Do Not look at just what Has failed on these report look at what has Not,

Thanks spook,

I had no idea it fired off so fast. So it seem safe to me now, to assume the airframe was intact until the last transmission at 0214z. And that transmission was only a warning of a crew ECAM advisory? Is that right? "Excessive Cabin Rate of Change" or something like that on the ECAM screen?

WN090601 2131 00206 ADVISORY

Am I wrong?

[Longtimer]

As most carriers use averages for baggage weight & passenger weight but actuals for the AirCargo units, the most likely area for weight error is not the air cargo (Frt, mail) load but rather in the bgge / pax weights. I know there is a fudge factor built into the W&B but have always wondered how close the average wt was to the actual all up load (Pax, Bgge & Cgo).

[avspook]

@Captain-Crunch

Yes Thats my present theory until new evidence is presented

[PPRuNe Pop]

OK! I have had enough of the perpetual "why has my post been deleted" and "what was wrong with my post?" - it goes on and on.

The problem is this: Some people are seriously in love with their keyboard and love to hear it's clatter. In other words they are making no contribution to this thread.

Some are making posts that are a mile off topic and deserve the chop. They are just not good enough.

Some simply do not know what they are talking about. WE can clearly recognise who the pros are and the positive contribution THEY make. Others will get heaved out of the way.

There IS an opinion, and that is all it is since no-one knows the facts yet, that an event took place that has SOME bearing but by no means the answer. Look and you will see it.

Further, we at PPRuNe are well aware that the press engage PPRuNe to get information. Bearing this in mind it means that we are not going to allow this to a rubbish based thread.

There are those who plainly spout rubbish - some are spouting total crap! We will and DO delete them. So you had better get used to it.

Forget asking why your post was removed. It ain't going to get an answer. If we decide it goes it goes.

We are doing our level best to accommodate those who play a sensible game of lexicon but idiots and chancers are on a hiding to nothing.

Danny, a few days ago, put it very succinctly why this thread is getting clobbered and I am using a great deal of control to avoid using my ancestorial background language of the anglo-saxon.

Good well thought out posts stay crap goes - the answer is if it goes it must be........get the picture.

[Swedish Steve]

One of the 24 ACARS messages sent by the airplane was EFCS PROBE 1+2/2+3/1+3 specifying so that all probes was in default.

Can you show the source of that statement. That wasn't on the original list of messages that I have?
There was EFCS1 and EFCS2. Not unusual considering what came before.

Given the two ADIRU and the ISIS failure are the pilots left then with no attitude information whatsoever Or did they have attitude but no speed?

Please remember that ISIS and ADIRU have attitude info and airspeed info. The two systems are nearly separate.
The airspeed info was at fault. There is no evidence yet of attitude indication problems.

[Interflug]

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

that is precisely max. takeoff weight.

Aircraft Family - A330-200 Specifications (http://www.airbus.com/en/aircraftfamilies/a330a340/a330-200/specifications.html)

**speculation**
could someone have tampered with the documented weight in order to stay within margins, avoid timeout etc?

could the pilots have been unaware they were too heavy?

could a sudden temperature change flying over an upwind in a CB have pushed the airplane beyond coffin corner, because the margins were consumed by the additional weight?

[avspook]

WN090601 2131 00206 ADVISORY

you are correct.

The only odd bit is the Advisory tag on the end. I cannot remember seeing that format before perhaps someones has an AF MM.

Again, to get the report to hit the satellite the Beam Steering unit needed PPOS/, from the NAV sys to know where to look for the SAT , a few degrees of uncorrected POS error or the SAT being shielded by the wing or similar & the signal is gone.

[Captain-Crunch]

Excellent work Avionics Spook :ok:

What about the HF? If the machine was in a high dive (no sat), could report of the Amber ECAM Advisory go out on HF? Say as customer option. AF was tight with AB, maybe they had all the bells and whistles.

Additionally, I suspect the ADVISORY comment is to call to attention the fact that this is not a real red warning to the crew.

It's a minor Amber "Excessive Cabin Rate of Change" ECAM low-level advisory (not an ECAM warning; not a loss of pressure as the press keeps thinking.) If it had been a bang, it would have been a red: Cab Alt Warning with associated Pressurization controller faults.

But it wasn't.

But maybe acars format only had faults and warnings.... who knows. It is to alert mtc to the fact that pressurization issues may have to be dealt with before re-dispatch, if my guess is correct.

Thnx

CC

[SergioR]

According to O Globo, not only more bodies have been localized this morning. Also "hundreds of items" are being currently localized in the debris area and will be stored for further identification and analysis.
Any information will be first forwarded to the families of the victims.

UPDATE: FAB sources said some minutes ago "there no more doubts the bodies and the itens being currently collected come from flight AF 447".
FAB confirmed three more bodies were found during an intense research last night. FAB planes localized more bodies in the area. More information is expected in the next few hours.

[EDLB]

could the pilots have been unaware they were too heavy?

@interflug

The flight was obvoius stable and therefore not stalling when the ACARS messages where sent. But the messages showed that the ADIRU and ISIS lost the airspeed information.
They where 3 houres in the flight. Therfore any overweight (which I highly doubt) at TO would not be an issue given the fuel allready burned.

For me its sounds at this time more like (very)partial panel flying at night likely in clouds, in turbulent air at high altidude with has much lower margins left over.

Thats enough of a recipe to kill even the best pilots around.

[Thermal Rider]

Dougydog asks
Questions; That last acars msg....cabin vertical speed...Does it mean the cabin is going to `over take` the outside ie airplane in a dive or does it mean decompression??

The other way around, that the outside air pressure is going to over-take that of the cabin unless the cabin gets recompressed at a rate unpleasant to the pax. Specifically, it means that the re-compression rate of the cabin is higher than 1800ft/min if cabin pressure intercepts outside pressure upon landing. The pressure intercept is managed by the system automatically based on key inputs, one of them the descent rate of the ac. The warning indicates that the pax are heading for an ear pop.

[p51guy]

My guess is as it passed about 8,000 ft and caught the cabin altitude the cabin altitude started a high descent rate close to what the aircraft descent was. If it was a decompression it probably would have happened earlier at a much higher altitude. Does anyone know if the cabin pressure controller sends the failure message or a cabin altitude sensor?

[Will Fraser]

One expects the last message sent by crew, 'hard turbulence...', was done in a calm manner with the involvement of the Captain. A very experienced man, it is unlikely the communique was transmitted lightly.
Logic suggests the crew have informed us of their flight's end. The precise physics of the event will be known in time, or perhaps not. Respectfully.

Will Fraser

[Interflug]

The flight was obvoius stable and therefore not stalling when the ACARS messages where sent. But the messages showed that the ADIRU and ISIS lost the airspeed information. Wasn't said here, that ADIRU and ISIS had conflicting input, rather than total loss of input?
They where 3 houres in the flight. Therfore any overweight (which I highly doubt) at TO would not be an issue given the fuel allready burned. A weight error would remain constant. It would be an issue for calculated max. altitude for the whole flight. How that could be practically relevant I don't know.

[Rainboe]

I have not contributed to this thread given the lack of facts. I am increasingly irritated by the assumption being made by some posters that a professional crew somehow flew the aeroplane in a not-sensible environment, 'or had the weather radar brilliance turned down!' Can people just shut up from making daft assertions until more facts are known? And PLEASE stop whinging for the flight recorder! How many times do people have to call for it? It will eventually be located- if it humanly can be, it will be retrieved. There is no point people banging on about it. We all know when it is retrieved, we will know more- we don't need to be told by one more poster! There is no point people accusing the crew of anything at this stage- we just don't know what happened. There is no point analysing made-up fiction to the nth degree at this stage, or peoples' pet theories.

This is meant to be a Professional Forum with sensible contributions. It looks whenever there is a big incident like an extension of airliners.net! What a cocophany of stupidity these threads become! There is no reason this thread should be more than 5 pages at this stage. The one positive thing is we seem to have gotten over having to give mawkish condolences every post.

[avspook]

@Captain-Crunch

Yes you can imagine how Maintenance Control Felt as the messages started to light up their screens.

These messages would have appeared live on someones workstation

I am aware of an airline that took a HF Datalink for their aircraft as a cost mitigation however it was never activated (to my knowledge)

As for Txing in a dive, possible but the HF uses 3 phase power AC & a coupler so the chances of failure would increase (In my opinion)

[Art-Deco]

First thread and not pilot, hope this is ok anyway with you all.

Could someone in pilot or eng-profession give a hint if my speculation in the following matter is of the wall or maybe possible in this tragic event?.

ACARS txm:s is via VHF ground network or switched to L-band via Satcom. Therefore it is normal that amatuers don´t pick up any of the txm:s on L-band. If the downed 330 had an array-mounted antenna for L-band txm:s and was doing a violent out of control flight, mother in Paris (receiving dish) should have a threshold point on rx, and as the flight may have been doing a lot of txm:s, it would be possible that more txm:s was aired but not recived by "mother" due to the gain-step setting (eB/no) in the receiver in Paris if the array-antenna was out of it´s prime focus during the last minutes.

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 issue is if ACARS is encryped and how hard encrypted any ACARS-txm:s would be to decode.

Is there a back-up recordings at Satcom NOC downlink-station, or is Paris the only active downlinker for AF ACARS txm:s. It could maybe be a good idea to spread the world to the L-band people and ask if someone was recording Satcom ACARS on june 1st on 1700 band, especially if worst scenario occurs were´s the "blaxboxes" never gets retrived or are in a degraded condition.

Just a thought in this tragic situation.

Sincerely
Thomas in Stockholm / engineer.

Edit-1: Not sure if this link is the right antenna-config, but phase-arrays can be tilted a lot and mantaine communication, suspect more that the CB:s would damp the signal to a critical threshold depending on downlink size of dish and eb/no-setting.
Link is: http://www.emssatcom.com/pdf/AMT-3500.pdf

Edit-2: 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. So with the NOC data and the previous post of the ASCARS messages, it could may be possible to determind the angle of the A/C if a calculation was made of NOC telemetri-data compared with the time-stamp of ACARS txm:s, as we know the pattern and how is mounted on the A/C body.

Edit-3:
foootprint map of ACARS-service reveils degraded zone within the same area: http://www.alphatelecom.ru/inmarsat/images/engmap.jpg

[Flyinheavy]

There is much talk about high altitude performance in this thread. May I remind You that the flight plan called for a step climb to FL370 at SALPU.
To my knowledge there has been no attempt either by HF (Atlantico) nor by relay transmission to get a clearence.

I could imagine that they did so in order to increase their performance.

@Rainboe: absolutely correct.......

[foxenburg]

Media make much about autopilot being disengaged. Until recently, one is led to believe, disengaging autopilot in CB was sop. Is the Airbus autopilot of a type that could be expected to cope with wild excursions or would a pilot switch it off if he saw things were becoming hairy? Thank you for your patience.

[Mercenary Pilot]

Dominique Bussereau the French Transport Minister has been quoted as saying.....

that it is too early to reach conclusions but has confirmed that the speed readings and their impact on the Airbus automated flight system are at the focus of the inquiry.


"Obviously the pilots did not have the right speed showing, which can lead to two bad consequences for the life of the aircraft: under-speed, which can lead to a stall, and over-speed, which can lead to the aircraft breaking up because it is approaching the speed of sound and the structure of the plane is not made for resisting such speeds,"

[venux]

The other way around, that the outside air pressure is going to over-take that of the cabin unless the cabin gets recompressed at a rate unpleasant to the pax. Specifically, it means that the re-compression rate of the cabin is higher than 1800ft/min if cabin pressure intercepts outside pressure upon landing. The pressure intercept is managed by the system automatically based on key inputs, one of them the descent rate of the ac. The warning indicates that the pax are heading for an ear pop.


So if the cabin pressure is at 8000ft, this warning suggests that the a/c is descending at a rate such that it would hit the water in less than 4.5 minutes, correct?

Or could this warning also be a result of bad air pressure data from iced-up probes?

[Dairyground]

There was some discussion at about midday Sunday 7th June, in posts around #465, concerning thepossibility and usefulness of an automated Mayday facility. The objections seem to be from traditionalist professionals who quote the Aviate, Navigate Communicate philosophy drummed into them at an early stage in their flying career. ANC is perfectly reasonable in situations where the flight crew have the time and space to establish reasonably stable flight, work out where they are and where they can go in the immediate future, and then inform the rest of the world. In such cases early communication may not be of any advantage to that flight or to anyone else. However, there are other situations where very early announcement could be very useful. If coupled to a GPS and other sensors, an automated Mayday could give precise positional and other information; it could produce high quality sound in clear English, without the intrusion of background noise; it could make other aircraft aware of someone nearby who was having to ignore normal separation rules; and if the worst came to the worst, it would give SAR a good position from which to start searching.


On different theme, Interflug speculates (in post #498 at the time of writing):


could someone have tampered with the documented weight in order to stay within margins, avoid timeout etc?
could the pilots have been unaware they were too heavy?


Would any significant excess weight become apparent to the crew once airbourne as a difference between actual and expected Angle of Attack for the current altitude and airspeed? Are instrument displays sufficiently precise to make any such discrepancy apparent, and if so is it the sort of thing the crew would notice and take into account?

[Flyinheavy]

According to german magazine 'Der Spiegel' there is allready a discussion going on between aviation safety experts to implement a system to automatically transmit FDR datas by satellite.

[golfyankeesierra]

CNN reports (http://edition.cnn.com/2009/WORLD/americas/06/07/brazil.plane.crash/index.html) total bodies recovered up till now is 5.

Re weight: F350 with max weight and high temp is not a problem, especially since they've been 3 hrs in their flight.

[dicksorchard]

Sadly I think that in relation to this particular incident the role of the forensic pathologists may be crucial in helping determine what actually happened to the passengers & crew and therefore will be a valuable resource for the accident investigators .

There is a wealth of information available on the internet in concerning the discoverys of forensic pathologists with relation to Air Accident investigations.

And Air accident investigators have found crucial evidence contained within post mortem reports that have in the past enabled them to discover what actually occurred to the aircraft and its passengers .

In fact concerning the speculation concerning the recent Russian accident report & the charge that the pilot was in fact drunk while in charge of his aircraft is in fact a highly contentious issue amongst medical professionals . test results can be altered by many different factors .


see below taken from forenscic science international

Elsevier (http://www.fsijournal.org/article/S0379-0738(06)00289-1/abstract)
Interpreting results of ethanol analysis in postmortem specimens

interpretation of BAC in autopsy specimens from the pilot and crew is highly contentious and great care is needed to reach valid conclusions.

Thankfully the fact that bodies have now been discovered can only help the air accident investigators in their quest to find out exactly what happened to this aircraft , its crew and its passengers .

[mixture]

traditionalist professionals who quote the Aviate, Navigate Communicate philosophy

I do not want to clutter up this thread with an off-topic debate about the supposed pros/cons of a button push mayday.

What I do want to say, however is there is nothing "traditionalist" about the ANC philosophy. I hope that the majority of pilots on PPrune would agree with me here !

It is a very important philosophy, there are multitude of excellent reasons why it is taught to pretty much all student pilots. Correct and professional prioritisation is critical in a flight deck environment, irrespective of whether you are flying a SEP or Jet and irrespective of whether you're flying as single PIC or MCC ops (with appropriate MCC considerations about flight deck level communication of course e.g. DODAR and NITS, or however else you want to put it !).

[Omykron]

Brazilian Air Force and Navy had sight of multiples bodies on the water and wreckage from the airplane, yet, awaiting visual confirmation and news from those authorities.

[lomapaseo]

Until the causal chain (multiple factors) is established I do hope that we can keep the opinions about good and bad aircraft design out of this thread. That kind of stuff belongs in generic technical discussions.

The how does it work on an A330 stuff is appropriate for this thread.

[Flyinheavy]

@Thermal Rider

'and assuming a descent from FL370 would extrapolate into a descent rate of 9000ft/min or more to trigger the warning'

We have no clue by now about the possible start of descent. Any calculation can only be faulty.

By the way, there is also no indication that the flight was at FL370

[Gary Brown]

At various points in this and other thread there has been reference to a message from AF 447 regarding the aircraft being in "hard turbulence" in a storm-cloud system. The very earliest versions of this supposed message even referred to the pilots being "cut off" in mid-conversation, or in mid-text message.

Given that this would be the *only* direct evidence of AF 447 actually being in or very near the storm system (rather than just appoaching it), does anyone have a direct AF / Airbus / BEA source for the "information".

Part of my reason for asking is that some French-language discussion groups (who also can't find a direct source) are suggesting the the "information" is based on a mis-translation of something Airbus said early on about "reports having been received" of hard turbulence, but not necessarily from AF 447 itself.

AGB

[bratschewurst]

Please forgive in advance intrusion by ex-amateur pilot and frequent passenger.

Two things stand out for me after having followed this discussion from the beginning. The first is that no pilot of the experience of the AF crew would willingly end up in the weather situation they were in. And yet they did. That suggests either a failure of the weather radar, a failure of interpretation, or a weakness in the pilot/radar software interface (which could lead to a failure of interpretation of the weather radar). Other similarly-experienced crews were successfully dealing with the same weather system that night. So what was different about AF 447?

It is striking that crews in this part of the ITCZ have no real-time tools to deal with convective activity other than the onboard radar. PIREPs seem few and far between (and hampered by problems with HF), there’s no ground-based radar of any kind (ATC or dedicated weather radar) to assist, and there appears no current way of getting any detailed information from the weather satellites, which at least would provide a bigger picture of what’s behind whatever the onboard radar is painting. It appears that, by comparison with crews dealing with the same kind of weather in a continental context, crews traversing the ITCZ over the oceans are flying with the equivalent of at least one eye shut.

The other thing I found striking is trying to imagine what that cockpit must have been like with all the alarms going off, trying to make sense of multiple failures happening virtually simultaneously, trying to reset computer systems, and all while trying to hand-fly an aircraft to maintain a very delicate balance between stalling and overspeed without accurate airspeed information – while in the kind of turbulence that’s not a common experience even for the most experienced crews – and at night.

Not getting accurate airspeed information is bad enough in that situation, and would have presented a very difficult challenge all by itself (harder, perhaps, that the one the AeroPeru crew faced – at least they didn’t have to deal with a very narrow margin between stall and overspeed). But having to be computer operators at the same time?

That’s not to say that a Boeing crew would have had things any easier. But there are downsides to automation in any context. Airbus normal law would undoubtedly have saved the Buffalo Dash-8 crew from stalling. But being surrounded by computers, all screaming failure at the same time, couldn’t have helped the AF crew deal with what was already a horrible situation.

[GSPLAJ]

Referring to suggestions of "push button mayday systems" or "automated mayday systems with GPS reference" in previous posts:

Would manual activation of ELT be an option once a crew realizes they are unable to regain control of the aircraft and the aircraft is doomed to crash/ditch?

In a case like this the SAR team would have saved 5 valuable days and possibly could have saved lives of any survivors.

Is manual ELT activation as a last resource ever discussed / considered during crew training?

[rattler46]

Captain-Crunch (http://www.pprune.org/members/296258-captain-crunch)

The satcom has got to be pointing up.... We're lucky we got a message in the dive at 2014z (if that's what happened.)Either we were lucky, or should one conlcude it still *was* pointing up when handing out this msg?

While I have been following both threads in detail and know it ws mentioned, but I do not recall exactly whether the transmission method of ACARS msgs had been firmly established?

EDIT: I see this has been at least partially answered while I typed. Ignore my question.

Rattler

[shamen123]

From ACARS:

FBW alternate law
Rudder Travel Limiter FaultSo, 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.

[Coyote44]

Amidst all the speculations thus far, I find it strange that nobody has jumped onto a story posted much earlier by some-one who spoke to some passengers who were on the 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. Now, was this problem snagged (reported) after landing, and released as "unable to duplicate snag"? Could this same "black-out" have occurred again, this time in or near a CB ? Whatever this black-out was, as far as I can remember, if one does get something resembling a "black-out" (any major system trip-off), it never was a simple problem...usually the start of a multiple failure of sorts. What if.......

[berenpx]

Surely, sticking to the South American east coast for a few hundred miles more, before heading across the water would reduce the risk.

Ok, it would cost a bit more.

I believe they didn't have any deviation fuel because the PIC didn't request any in RIO.

If they had, I'm sure AF would have pointed out that fact by now.