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Old 6th Jun 2009, 20:04
  #361 (permalink)  
 
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@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
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Old 6th Jun 2009, 20:52
  #362 (permalink)  
 
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"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
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Old 6th Jun 2009, 20:56
  #363 (permalink)  
 
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barry try again.

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

how many does that leave?
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Old 6th Jun 2009, 21:00
  #364 (permalink)  
 
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I have never heard of a blocked pitot causing an antenna fault, for example..
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Old 6th Jun 2009, 21:13
  #365 (permalink)  
 
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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.
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Old 6th Jun 2009, 21:13
  #366 (permalink)  
 
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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.
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Old 6th Jun 2009, 21:18
  #367 (permalink)  
 
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Thanks all

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
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Old 6th Jun 2009, 21:23
  #368 (permalink)  
Stercus Accidit
 
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# 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
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Old 6th Jun 2009, 21:24
  #369 (permalink)  
 
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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?
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Old 6th Jun 2009, 21:25
  #370 (permalink)  
 
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well name them. TCAS is related so what other ones are you on about
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Old 6th Jun 2009, 21:30
  #371 (permalink)  
 
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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.
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Old 6th Jun 2009, 21:34
  #372 (permalink)  
 
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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
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Old 6th Jun 2009, 21:36
  #373 (permalink)  
 
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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.
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Old 6th Jun 2009, 21:37
  #374 (permalink)  
 
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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
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Old 6th Jun 2009, 21:39
  #375 (permalink)  
 
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Check the link

AMF

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

GF
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Old 6th Jun 2009, 21:41
  #376 (permalink)  
 
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@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
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Old 6th Jun 2009, 21:49
  #377 (permalink)  
 
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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.
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Old 6th Jun 2009, 21:58
  #378 (permalink)  
 
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What was different?

Possibly the weather & the ITCZ
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Old 6th Jun 2009, 22:05
  #379 (permalink)  
 
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Try this link to AMF's interesting FAA document

http://www.flightsafety.org/pdf/AP_U...Supplement.pdf
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Old 6th Jun 2009, 22:07
  #380 (permalink)  
 
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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...
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