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Thread: Air France Flight 447

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    Theophilus's Avatar
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    Air France Flight 447

    I read an article about AirBus issuing a warning to pilots not to re-engage the automatic pilot after getting false airspeed warnings. It also seems that AirBus is going to get blamed for this accident. I wish I could find that article again damn it. Anyway things seem to pointing towards that this accident was not caused by pilot error, but a flaw with the planes sensing equipment.

    This was a terrible disaster. I am wondering is this accident was not just a flaw in the equipment, but maybe a combination of the air traffic control, the pilots and the sensing equipment.

    Air France Flight 447 - Wikipedia, the free encyclopedia

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    A Life Aloft is offline fled troglodyte invasion
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    Re: Air France Flight 447

    Hey buddy! I just looked this up. I had been following this crash for many months after it initially happened, but have not much since. The data and flight recorders and the majority of the wreckage of the aircraft have never been found. And at this point, I seriously doubt that the boxes will be found and if they are, the data may be long ruined. Here is the bulletin that I just found:

    "Airbus warns about a potential malfunction of speed sensors on aircraft like the Air France A330 that crashed into the Atlantic last year, killing all 228 people aboard.

    Airbus sent the warning regarding Pitot tubes to the 100 operators of its A330 and A340-200 and A340-300 jetliners..

    Airbus said in some cases two Pitot tubes can give matching, incorrect speed data, which could lead pilots to re-engage autopilot prematurely. The warning advises pilots not to re-engage automatic pilot following questionable readings from airspeed indicators until they have double-checked the readings.

    Pitot Tubes are suspected of a role in the June 1, 2009, Rio-to-Paris crash that came during a strong thunderstorm over the Atlantic. Automatic messages sent by the plane's computers just before it crashed show it was receiving false air speed readings from its Pitot tubes.

    The Air France crash probe is still centering around possible icing of the jetliners pitot tubes. Telemetry received from the airplane gave inconsistent airspeed readings just before contact with the aircraft was lost. Investigators have insisted that a series of failures, and not the Pitot tubes alone, likely caused the crash.

    The telex from Airbus cautions flight crews to check airspeed indications before engaging the autopilot.

    The complete text of the telex reads:

    FROM : AIRBUS CUSTOMER SERVICES TOULOUSE

    TO : ALL A330/A340 CFM GE PW RR OPERATORS

    FLIGHT OPERATIONS TELEX - FLIGHT OPERATIONS TELEX

    Subject: ATA 22 and 34 - Loss of AP and A/THR associated with alternate law reversion

    CLASSIFICATION: AIRWORTHINESS

    Notice: This FOT provides information about a significant operational issue that is related to airworthiness or safety. It is each Operator[sup.3]s responsibility to distribute this FOT or to distribute the information contained in this FOT, to all of their applicable flight crews without delay. Failure to apply this FOT may have a significant impact on safe aircraft operations. This FOT and the OEB advance copies will be available in pdf format in AirbusWorld within two days.

    1. PURPOSE

    The purpose of this FOT is to recommend the flight crew to check airspeed indications before engaging the autopilot, when in alternate law.

    2. EXPLANATION

    When there are significant differences between all airspeed sources, the flight controls revert to alternate law, the autopilot (AP) and the autothrust (A/THR) automatically disconnect, and the Flight Directors (FD) bars are automatically removed. It has been identified that, after such an event, if two airspeed sources become similar while still erroneous, the flight guidance computers:

    * Display FD bars again.

    * Enable autopilot and autothrust re-engagement.

    However, in some cases, the autopilot orders may be inappropriate, such as possible abrupt pitch command. Therefore, the flight crew must apply the following procedure.

    3. OPERATIONAL RECOMMENDATIONS

    When autopilot and autothrust are automatically disconnected and flight controls have reverted to alternate law:

    * Do not engage the AP and the A/THR, even if FD bars have reappeared

    * Do not follow the FD orders

    * ALL SPEED INDICATIONS......................................X- CHECK

    If unreliable speed indication is suspected:

    UNRELIABLE SPEED INDIC/ADR CHECK PROC...........APPLY

    If at least two ADRs provide reliable speed indication for at least 30 seconds, and the aircraft is stabilized on the intended path:

    AP/FD and A/THR ......................................As required.

    4. CORRECTIVE ACTION

    This procedure will be cancelled by the next FCPC standards that will be available before end 2011. This modification will inhibit autopilot engagement in the above described situation.

    5. FOLLOW-UP

    For A330 aircraft, these operational recommendations will be issued by beginning of January 2011 in red OEB 82/1 and its associated OEB PROC 82/1 in the QRH. For A340-200/-300 aircraft, these operational recommendations will be issued beginning of January 2011 in red OEB 95/1 and its associated OEB PROC 95/1 in the QRH."

    It's gets worse now, because I also found this:

    Associated Press
    Airbus faces charges over 2009 Rio-Paris crash
    by PIERRE-ANTOINE SOUCHARD , 03.17.11, 12:50 PM EDT


    "PARIS -- A French judge filed preliminary manslaughter charges Thursday against Airbus over the 2009 crash of an Air France jet - opening a rare criminal investigation against a corporate powerhouse.

    The order from Judge Sylvie Zimmerman targeting the European planemaker centers on the June 2009 crash into the Atlantic of an Airbus A330 bound for Paris from Rio de Janeiro, killing all 228 people on board.

    Airbus chief Thomas Enders, speaking to reporters afterward, said the company disagreed with the judge's "premature" decision - especially in light of the still-unsolved mystery about the crash.

    The preliminary charges, which allow for further investigation, came after Airbus lawyers met with the judge on Thursday. Enders said Airbus will continue to cooperate with the probe.

    Charges against Airbus, the world's top planemaker by orders in 2010 and a rival of Chicago-based Boeing ( BA - news - people ) Co., are unusual but not unprecedented. Airbus employees have been charged in France in previous crashes.

    Air France flight 447 went down June 1, 2009, amid an intense, high-altitude thunderstorm. Automatic messages sent by the plane's computers show it was receiving false air speed readings from sensors known as pitot tubes. Investigators have said the crash was likely caused by a series of problems, and not just sensor error.

    Specialists are launching a fourth undersea search effort next week for the plane's so-called black boxes, or flight recorders.

    "We are convinced if we find the black boxes we'll be able to reconstruct what really happened on this tragic flight Air France 447," Enders said. Airbus officials say the search is a company priority.

    Air France and Airbus will finance the estimated $12.5 million cost of the new search, in which three advanced underwater robots will scour the mountainous ocean floor between Brazil and western Africa, in depths of up to 4,000 meters (13,120 feet).

    Already $27.5 million has been spent on three previous search attempts that failed to find Flight 447's voice and data recorders.

    The exact role the sensors played in the crash may never be known without the flight recorders.

    Airbus knew since at least 2002 about problems with the type of speed sensor that malfunctioned on the doomed jet, The Associated Press has reported. But air safety authorities did not order their replacement until after the crash.

    The tubes, about the size of an adult hand and fitted to the underbelly of a plane, are vulnerable to blockage from water and icing. Experts have suggested that Flight 447's sensors, made by French company Thales ( THLEF.PK - news - people ) SA, may have iced over and sent false speed information to the computers as the plane ran into a thunderstorm at about 35,000 feet (10,600 meters)."



    From studying the ACARS messages as I did after the crash there were a series of horrendous cascading failures aboard the aircraft. Dire failures. There was so much speculation on so many levels, from weather issues, to pilot issues to equipment issues that the variables just became enormous. I was involved on a forum for pilots and others in various aviation roles, discussing this in just thousands of posts (I mean the discussions grew so large that several new continuation threads had to be started because each thread became so long) but the waters became so muddied with all of the possibilities of what could have happened and how, that after several months, I just moved on from the discussion. No real conclusions, but only a series of possibilities were held up as to what may have happened and even the report from French Officials was lacking in it's conclusions as nothing concrete could be discerned at the time. Nothing has ever been satisfactorily resolved at this point. There is still the issue of why this flight appeared to go straight through a severe towering thunderstorm that other flights crossing through the same storm zone that night just preceeding and after AF447 were actively diverting around the most severe of the storm cells, (there were several in the area at the time, and as I remember there were three major cells along with other cells in the area) while the Air France flight didn’t seem to deviate at all.

    But, there have been some very harrowing cases of iced up pitots on the A330 causing unreliable air speed indications and a significant but relatively short control of flight issue for pilots, with very well reported cases concerning a Northwest flight and two Air Caraibes flights. None of these encounters with a control issue caused by two or three of the three pitots being temporarily blocked actually threatened to cause the destruction of the airliner though. But they were also flying in different circumstances. Then came the hurried notices and replacements of the pitots shortly after the crash of AF447. There just are so many factors to be considered. From reading the weather in the area at the time, it had to play a role in this accident. They would have been flying through significant turbulence and thunderstorm activity for about 75 miles (125 km), lasting about 12 minutes of flight time. This had to mean severe turbulence, hail, lightening and who knows what all. Did the Captain not realize/understand the severity of that specific storm? Then one can get into entire discussions of how to properly manipulate the radar to get the best results in readings, your experience and training with cells and on and on. There is also the consideration of all the cascading system failures. What role did the pilots play in all of this? What role did the systems themselves (including the pitots) have in this disaster? What procedures were followed and in what order? So many questions and so few answers. And the list of speculations, opinions and possibilities is very, very lengthly and varied regarding this accident. I don't see without the recorders what hard evidence is going to be used in court to proove what exactly caused this crash. Personally, I believe it was a combination of several events, but I am no expert. I don't even want to get into how tied up AF is with the French Government, since they are heavily funded, financed and supported by them. That in itself is another whole can of worms. I hate to say this, but this whole thing may be a way of the French Government to limit it's liability in the matter and in respect to limiting or capping the monies paid out to the families of the victims and that the compensation would have to come directly from Air France and their reserves. Afterall, remember the French Governent's attitude in respect to the Concord disaster.

    It will be interesting to see how this plays out. Thanks for bringing this up. I was not aware that a suit had jut been filed, nor of the latest issuance of the bulletin regarding the pitots.
    Last edited by A Life Aloft; 03-22-2011 at 01:32 AM.

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