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AF447

Old 7th Jun 2009, 13:35
  #461 (permalink)  
 
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I am sorry, Sir but your statement is out of line. I have chosen not to participate in the discussion taking place in this thread about this particular accident but a thing or two must be put into perspective.

lhp:
if the facts in this thread hold out, it will be pretty obvious that the A330/200 is a death trap if it can't safely operate at the most common altitude between FL300 and FL400 under heavy WX.
First of all, you are talking about an aircraft which is in operational status for 15 years. Do you think this was the only time an A330 flew at those altitudes in this weather? So "death trap" and other popular and populist i might add phrases have no place here, in my - strong - opinion.

Second, and most important objection: This thread and its "facts" is not a substitute of any investigation that i am, or we are for that matter, aware of.

So as much as i respect my colleagues who fly the Airbus and the rest of us who fly Boeing or other commercial aircraft and who have chosen to simply "think aloud" as to what might have happened (i have not done that because i wait for hard evidence and conclusive facts from the investigating authorities and the manufacturer), those views are NOT official investigation material.

In my opinion, which i humbly put it into public view, no professional aviator flying commercial jets should say "ABC happened and therefore in the A330 XYZ could be problematic" before any conclusive report makes it into daylight. Again, that is my opinion and my opinion only. I'm not saying I am right to say so, although i suspect a lot of my colleagues will agree with it.
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Old 7th Jun 2009, 13:38
  #462 (permalink)  
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barry, unless the possible position of the surface fires is within the debris drift area then it is a non-starter.
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Old 7th Jun 2009, 13:44
  #463 (permalink)  
 
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Barrymung

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?
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Old 7th Jun 2009, 13:47
  #464 (permalink)  
 
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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.
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Old 7th Jun 2009, 13:55
  #465 (permalink)  
 
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Interflug

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.
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Old 7th Jun 2009, 14:00
  #466 (permalink)  
 
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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?
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Old 7th Jun 2009, 14:05
  #467 (permalink)  
 
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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?
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Old 7th Jun 2009, 14:21
  #468 (permalink)  
 
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Regarding weight

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).
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Old 7th Jun 2009, 14:31
  #469 (permalink)  
 
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@Captain-Crunch

Yes Thats my present theory until new evidence is presented
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Old 7th Jun 2009, 14:33
  #470 (permalink)  
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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.
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Old 7th Jun 2009, 14:41
  #471 (permalink)  
 
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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.
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Old 7th Jun 2009, 14:44
  #472 (permalink)  
 
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Nosegear

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

that is precisely max. takeoff weight.

Aircraft Family - A330-200 Specifications

**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?
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Old 7th Jun 2009, 14:55
  #473 (permalink)  
 
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Captain-Crunch

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.
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Old 7th Jun 2009, 15:14
  #474 (permalink)  
 
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The plot thickens

Excellent work Avionics Spook

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

Last edited by Captain-Crunch; 7th Jun 2009 at 15:50.
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Old 7th Jun 2009, 15:25
  #475 (permalink)  
 
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hundreds of items localized

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.

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Old 7th Jun 2009, 15:25
  #476 (permalink)  
 
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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.
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Old 7th Jun 2009, 15:32
  #477 (permalink)  
 
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Cabin vertical speed warning

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.
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Old 7th Jun 2009, 15:41
  #478 (permalink)  
 
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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?
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Old 7th Jun 2009, 15:49
  #479 (permalink)  
 
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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
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Old 7th Jun 2009, 15:53
  #480 (permalink)  
 
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@EDLB

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.
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