AF447 accident – still more on pitot tubes and salvage techniques

Adding to the evidence of earlier failures is this Air France memo to its pilots from last November. It’s in French but it warns of a significant number of similar incidents involving unreliable airspeed indications. It cautions pilots to be vigilant in conditions involving “high altitude, icing, turbulence” and and urges them to try to avoid being surprised and to fly gently if they end up in manual control.

Meanwhile French TV station TF1 has found an Air France mechanic who talks on air about the history of events, also in French. They’ve come up with some documents relating earlier incidents which you can see parts of below.


TF1 screengrab 1.JPG



TF1 screengrab 2.JPG













































AndAddison Schonland over at IAG, who has been creating a nice series ofpodcasts on AF447 has come up with several items. First he’s got an interview with an engineer about the ACARS messages (although I should say the interpretation is disputed elsewhere), then he has a written analysis of the messages by a pilot which is perhaps the most comprehensible version of the several so far published, and finally he has an interview with one Dr John Craven who is the veteran of a couple of epic underwater search operations and knows whereof he speaks. Fascinating stuff.

Andlastly today, Thales’ competitor on the A330 pitot system is Goodrich.Like Thales, Goodrich offers an upgraded system and here’s the product documentation, which is quite illuminating about the change – notably to the heating system. Here’s the relevant bit.


Goodrich pitot tube.JPG




























Adding to the evidence of earlier failures is this Air France memo to its pilots from last November. It’s in French but it warns of a significant number of similar incidents involving unreliable airspeed indications. It cautions pilots to be vigilant in conditions involving “high altitude, icing, turbulence” and and urges them to try to avoid being surprised and to fly gently if they end up in manual control.

Meanwhile French TV station TF1 has found an Air France mechanic who talks on air about the history of events, also in French. They’ve come up with some documents relating earlier incidents which you can see parts of below.


TF1 screengrab 1.JPG



TF1 screengrab 2.JPG













































AndAddison Schonland over at IAG, who has been creating a nice series ofpodcasts on AF447 has come up with several items. First he’s got an interview with an engineer about the ACARS messages (although I should say the interpretation is disputed elsewhere), then he has a written analysis of the messages by a pilot which is perhaps the most comprehensible version of the several so far published, and finally he has an interview with one Dr John Craven who is the veteran of a couple of epic underwater search operations and knows whereof he speaks. Fascinating stuff.

Andlastly today, Thales’ competitor on the A330 pitot system is Goodrich.Like Thales, Goodrich offers an upgraded system and here’s the product documentation, which is quite illuminating about the change – notably to the heating system. Here’s the relevant bit.


Goodrich pitot tube.JPG

































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7 Responses to AF447 accident – still more on pitot tubes and salvage techniques

  1. Francesca Colloredo June 11, 2009 at 9:43 pm #

    I’ve just read on CNN your article : “Air France crash: What do we know”. Of all the articles I have read on this tragic accident, you are the only one that asked the question that I have been asking myself since the crash: why was the plane flying through that storm? I have been flying as a passenger over the Atlantic for many years and encountered many strong turbulances, some of them quite scary. I was always told that modern planes are built to withstand most weather conditions at cruising altitude, not to worry. Obviously that’s not the case. I have the feeling that no matter what will be found out about the mechanical failures that brought the plane down, the storm will probably the main cause of this tragedy. Which brings me to the question, if that Intertropical Convergence Zone can be so dangerous because of the gigantic storms that produces, clouds at 51,000 feet and winds at 100mph, hail the size of tennis balls, why planes are still flying through it? Why alternative routes are not chosen? If these storms, in some cases (like probably the one of Air France) cannot even be seen or avoided, why not leave this flying zone alltogether? Maybe 223 lives will be cause enough for the various commercial airlines to rethink and change some of these dangerous routes.

  2. Anonymous June 12, 2009 at 12:53 am #

    Well, if you want to travel between the US or Europe and South America, what are you to do? The Equator is there.

    Furthermore, while the Air France crash obviously is a horrific tragedy, that doesn’t mean it is not safe to fly and that you should start worrying.

    I have no idea of the numbers, but if we assume that maybe 20 000 persons are flying across the South American Equator per day, that would make 7 300 000 persons each year. If we have gone for say thirty years withot a ICZ-related crash, that makes 220 000 000 safe travels.

  3. Andreas June 12, 2009 at 3:51 pm #

    It appears that Mr. Scholand’s expertise is not just questioned on PPRUNe. Maybe someone can comment on the validity of the criticism?

    http://leehamnews.wordpress.com/2009/06/09/podcast-details-af-acars-messages/#comments

  4. John Doe June 12, 2009 at 5:09 pm #

    A hundred years ago, a ship’s survival depended almost solely on the competence of her master and on his constant alertness to every hint of change in the weather. To be taken aback or caught in full sail on by even a passing squall might mean the loss of spars or canvas; and to come close to the center of a genuine hurricane or typhoon was synonymous with disaster.

    While to be taken by surprise was thus serious, the facilities for avoiding it were meager. Each master was dependent wholly on himself for detecting the first symptoms of bad weather, for predicting its seriousness and movement, and for taking the appropriate measures to, to evade it if possible and to battle through it if it passed near to him. There was no radio by which weather data could be collected from all over the oceans and the resulting forecasts by expert aerologists broadcasted to him and to all afloat. There was no one to tell him that the time had now come to strike his light sails and spars, and snug her down under close reefs and storm trysails.

    His own barometer, the force and direction of the wind, and the appearance of sea and sky were all that he had for information. Ceaseless vigilance in watching and interpreting signs, plus a philosophy of taking no risk in which there was little to gain and much to be lost, was what enabled him to survive.
    Both seniors and juniors alike must realize that in bad weather, as in most other situations, safety and fatal hazard are not separated by any sharp boundary line, but shade gradually from one into the other. There is no little red light which is going to flash on and inform commanding officers or higher commanders that from then on there is extreme danger from the weather, and that measures for ships’ safety must now take precedence over further efforts to keep up with the formation or to execute the assigned task. This time will always be a matter of personal judgment.

    Naturally no commander is going to cut thin the margin between staying afloat and foundering, but he may nevertheless unwittingly pass the danger point even though no ship is yet in extremis. Ships that keep on going as long as the severity of wind and sea has not yet come close to capsizing them or breaking them in two, may nevertheless become helpless to avoid these catastrophes later if things get worse. By then they may be unable to steer any heading but in the trough of the sea, or may have their steering control, lighting , communications, and main propulsion disabled, or may be helpless to secure things on deck or to jettison topside weights.

    The time for taking all measures for a ship’s safety is while still able to do so. Nothing is more dangerous than for a seaman to be grudging in taking precautions lest they turn out to have been unnecessary.

    Safety at sea for a thousand years has depended on exactly the opposite philosophy.
    — Admiral Chester A. Nimitz, USN
    13 February 1945.

  5. Gene June 13, 2009 at 4:48 am #

    You made the statement about the crew “struggling with an UNFAMILIAR check list at night”. THERE SHOULD BE NOTHING UNFAMILIAR on a checklist, if the crew has been properly trained! We don’t know, as yet, about all of the problems they were encountering, but an unfamiliar checklist is just stretching it a bit, don’t you think?

  6. Kieran Daly April 7, 2013 at 11:06 pm #

    I sympathise with Francesca’s point of view, but I’m afraid Anonymous is right. However, that doesn’t make the question go away.

    But as I wrote in that CNN article, we don’t really know how significant the weather actually was.

  7. Kieran Daly April 7, 2013 at 11:06 pm #

    Gene,

    all things being relative I suppose. Obviously no checklist is unfamiliar in that sense that the crew would never have gone through it before. But I very much doubt that many crews could recall the checklist, which is reasonably complex, from memory. And I suspect that of all the numerous checklists on the A330, that one would not be high among those frequently practised. It’s clear from the Air Caraibes document that the crew described in that, which seems to have done a good job, had to puzzle their way through the list on the day.

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