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  • Originally posted by Spectator View Post
    I agree 100%. The AirFrance manual is the only one applicable to discussions directly regarding this accident. But it is interesting to see other operators manuals while we discuss the general issue of how UAS is being handled at present.
    Absolutely. It's this lack of standardization that bothers me. I certainly hope these procedures have been revised fleetwide (A320/330/340).

    Comment


    • Originally posted by Evan View Post
      Absolutely. It's this lack of standardization that bothers me. I certainly hope these procedures have been revised fleetwide (A320/330/340).
      It isn't a lack of standardization. It is that different aircraft, with differences in avionics require different procedures Evan. Also, there have been several revisions since the AF447 accident. Finally, the operator is able to develop their own version of the FCOMs and SOPs and use them for their operation as long as it is certified and authorized by the proper governing authority. Thus why AF has a manual in french, and why some US carrier has the whole FCOMs completely different than airbus. Now, obviously, the French Aviation Authority would have to authorize it, and the FAA for the american carrier.

      Comment


      • Originally posted by ca787546 View Post
        It isn't a lack of standardization. It is that different aircraft, with differences in avionics require different procedures Evan.
        Since there is a cockpit commonality amongst the A330/A340 fleet (and many aspects of the A320 as well), what do you mean by different avionics? And how does this affect UAS procedure (aside from BUSS of course)? Can you explain this further?

        Also, shouldn't the manufacturer (Airbus) be prescribing these procedures directly from their engineering expertise? Certainly they are the best ones to design a procedure for stabilizing airspeed. Why is this left to operators?

        Comment


        • Knew it didn't add up:

          Investigation into the accident sequence of Air France flight AF447 has revealed that the Airbus A330 did not enter the abnormal attitude law after it stalled, despite its excessive angle of attack.
          http://www.flightglobal.com/articles...itude-law.html

          Comment


          • Originally posted by EconomyClass View Post
            Wow ~ this article really highlights the THS and logic issues that need to be addressed. How many Airbus pilots have ever used manual pitch trim in flight? It's no wonder they didn't use it this time. And it's NOT mentioned in the QRH. Is it even included in stall recovery training?

            If they had gone into Abnormal Attitude Law, the message USE MAN PITCH TRIM would have appeared on the PFD. So this is a real issue. Logic needs to be revised to ensure a high AoA sensor reading triggers this mode.

            After stalling, the A330's angle of attack stayed above 35°. But while this exceeded the threshold for the abnormal attitude law, the flight control computers had already rejected all three air data reference units and all air data parameters owing to discrepancy in the airspeed measurements.
            Full ADR rejection, all paramenters. Why throw the baby out with the bathwater Airbus?

            Comment


            • Der Spiegel and Prof. Hüttig again...:


              Victims' Families Propose Grounding All A330s


              Airbus believes pilot error caused the crash of Air France flight AF 447 two years ago. But the families of some victims think it might have been a technical defect. They have filed a petition with a Paris court which could result in a temporary grounding of all A330s.


              [...]

              The central questions are clear: Did the pilots react incorrectly once the speed sensors on the outside of the plane iced up and the automatic pilot disengaged? Or was an additional technical error to blame? Lawyers and technical experts for the families of German crash victims suspect that a hidden software error in the automated flight control system -- specifically concerning a vital stabilizer flap on the plane's tail -- doomed to failure all pilot efforts to regain control of the plane. They are demanding that the Parisian court investigating the crash take action. "We petition that appropriate action be taken to prevent a catastrophe similar to that which befell AF 447 from happening again," reads the letter submitted to Judge Sylvie Zimmermann, which SPIEGEL has obtained.

              [...]
              The Hanover legal practice of Ulrich von Jeinsen, which composed the letter, and the Berlin aviation law expert Elmar Geimulla made mention in the letter that there could be "criminal consequences" should indications of a software error not be thoroughly investigated and another Airbus crashes for the same reason.
              Von Jeinsen's motion is primarily based on the expert opinion of Gerhard Hüttig, a professor at the Institute of Aeronautics and Astronautics at the Technical University in Berlin. Just over a year ago, Hüttig recreated the Air France crash in a flight simulator. In the course of the exercise, Hüttig noticed a strange anomaly in the plane's reaction once it goes into a stall. The trimmable horizontal stabilizer, a flap instrumental in keeping the plane on an even keel, automatically adjusted to push the nose of the plane skyward.
              Hüttig, a former Airbus pilot himself, and other pilots present for the test were unable to push the nose of the airplane down and thereby escape the stall.
              When the BEA released its preliminary report last Friday, Hüttig immediately zeroed in on data relating to the trimmable horizontal stabilizer. During the final minutes of flight AF 447 as it plunged toward the Atlantic, the flap moved from a 3 degree deflection to a 13 degree deflection, almost the maximum possible. "The phenomenon is startlingly similar," he told SPIEGEL.

              [...]

              In response to a SPIEGEL query, Airbus rejected Hüttig's theory. The company has said that the deflection of the stabilizers can be explained by pilot attempts to pull up the nose of the aircraft.
              Other European airlines have begun analyzing the data from flight AF 447 in an effort to identify potential dangers to aircraft of the same model in their own fleets. A final and comprehensive report from the BEA is scheduled for release at the end of July. Aviation experts predict that the report will do little to forestall a brewing fight among the investigators, Airbus and Air France over who, ultimately, is responsible for the crash, which resulted in 228 deaths.

              Comment


              • Originally posted by Evan View Post
                Wow ~ this article really highlights the THS and logic issues that need to be addressed. How many Airbus pilots have ever used manual pitch trim in flight? It's no wonder they didn't use it this time. And it's NOT mentioned in the QRH. Is it even included in stall recovery training?

                If they had gone into Abnormal Attitude Law, the message USE MAN PITCH TRIM would have appeared on the PFD. So this is a real issue. Logic needs to be revised to ensure a high AoA sensor reading triggers this mode.



                Full ADR rejection, all paramenters. Why throw the baby out with the bathwater Airbus?
                I'm a little confused as to what your expectations of the pilots are, Evan. On the one hand, you want standardized procedures that pilots would carry out, as ca787546 said, like a robot, even though he explained to you how he would handle the situation using basic piloting skills - assessing the situation while maintaining stable flight, to put it in my layman's terms.

                Now you expect these same pilots, whom you don't even trust to carry out memory items, who don't seem to have done much in this instance to push the nose of the aircraft down in the first place, to also be thrown into an alternate law where they are expected to control pitch trim, something they never have to do?

                I can see that the pitch trim is becoming more of an issue (although Airbus is saying it is explained by the pilots nose-up inputs if I understand correctly), but your answer to the problem - demanding that the pilots use it manually under the most stressful of circumstances - seems inconsistent with your beliefs as to what their skill set is.

                Also, I see we've now come full circle with respect to media reports, now ready to submit recommendations to Airbus with every new leak.

                Comment


                • Originally posted by Fear_of_Flying View Post
                  I'm a little confused as to what your expectations of the pilots are, Evan. On the one hand, you want standardized procedures that pilots would carry out, as ca787546 said, like a robot, even though he explained to you how he would handle the situation using basic piloting skills - assessing the situation while maintaining stable flight, to put it in my layman's terms.

                  Now you expect these same pilots, whom you don't even trust to carry out memory items, who don't seem to have done much in this instance to push the nose of the aircraft down in the first place, to also be thrown into an alternate law where they are expected to control pitch trim, something they never have to do?

                  I can see that the pitch trim is becoming more of an issue (although Airbus is saying it is explained by the pilots nose-up inputs if I understand correctly), but your answer to the problem - demanding that the pilots use it manually under the most stressful of circumstances - seems inconsistent with your beliefs as to what their skill set is.

                  Also, I see we've now come full circle with respect to media reports, now ready to submit recommendations to Airbus with every new leak.
                  Sorry to confuse you, FOF. Let me clear that up.

                  I see three separate issues here, UAS, approach to stall and stall recovery. Each has its own set of procedures to follow.
                  • (1) For ANY instance of UAS in RVSM, I want pilots to apply CLB thrust (correctly) and 5° pitch (unless Airbus see fit to modify that), the only exception being if doing so will endanger the flight (the reverse of the current policy used by certain operators). If the PF AF447 had done that, there would have been no need for...
                  • (2) In approach to stall situations (stickshaker) in RVSM, I want pilots to ALWAYS apply corrective pitch reduction and then carefully add thrust if needed. Releasing backpressure on the stick will not reduce pitch on an Airbus in Normal or Alternate Law. If the PF AF447 had done that, there would have been no need for...
                  • (3) For full stall, I want them to know how to determine the nature of the stall and have full situational awareness. Now that, I realize, is a bit optimistic, but it is what I think we should always strive for. For instance, if the THS is at its upper limit, there isn't any chance of stall recovery, so pilots must be trained to expect this and to recognize that manual pitch trim might be required (USE MAN PITCH TRIM should also be displayed prominently on the PFD if auto trim is frozen). At present, I don't believe this is being taught and it is very rare that a pilot will ever have to fly in direct law and move the manual trim wheel in flight.

                  Is that clear now?

                  Maybe our old friend Prof. Huttig might be onto something, and there may be a bug in the system, or this might just be the auto trim attempting to trim the downforce out of a very steep FPV as commanded by the sidestick inputs. It is designed to do this. Even while falling out at 10,000+ ft/min, it appears that the commanded PFV was something like a 10° climb gradient. Or, they might have lowered the pitch command but it was ineffective because a bug kept the THS frozen at 13° ANU in alternate law. We need the FDR plots to determine this.

                  What I'm suggesting is that perhaps the logic needs to change so that AoA air data is still considered valid and the ADR's still partially valid. AFIAK*, when the pitots fail, the entire ADR is taken out of service. But if logic instead allowed the ADR's to continue providing AoA data to the EFCS, the flight would have entered Abnormal Attitude Law, and the autotrim would have frozen, and the PFD would have advised the pilots to trim manually. That's how I'm seeing it as this point.

                  -------------

                  *EDIT: However, I'm basing this on the FlightGlobal article the indicates:
                  Originally posted by FLightGlobal
                  After stalling, the A330's angle of attack stayed above 35°. But while this exceeded the threshold for the abnormal attitude law, the flight control computers had already rejected all three air data reference units and all air data parameters owing to discrepancy in the airspeed measurements.
                  But I question this because if this is true, how were they still getting stall warnings...?

                  -------------


                  So, three things. (1) obviously, pilot training STANDARDIZATION for UAS. (2) obviously, pilot training improvements to address the nature and use of the THS in stall situations (which should never happen on an Airbus). (3) investigate logic issues related to the THS, and possibly revise logic to allow partial ADR data during UAS situations to ensure Abnormal Attitude Law is active when it needs to be active.

                  Thus far, that's how I see it. The FDR data could tell us a different story however.

                  Comment


                  • I guess I find this guy pretty credible:

                    The airplanes themselves and the procedures involved in using them, Sullenberger said, need to be designed in such a way that pilots are "clearly in the loop, so that they are ready and able to intervene when things suddenly go wrong."

                    Sullenberger added, "That's an issue now, with these highly-automated airplanes."

                    He continued, "I can tell you from firsthand experience, after many years of thousands of routine flights, how sudden emergencies have a very huge startle effect, and it takes a lot of discipline to be able to focus clearly on the task at hand in spite of that."
                    http://www.cbsnews.com/stories/2011/...20067860.shtml

                    Comment


                    • Originally posted by EconomyClass View Post
                      I guess I find this guy pretty credible:

                      http://www.cbsnews.com/stories/2011/...20067860.shtml
                      Sully kept his head though, didn't he. Sully was well "in the loop". It's not the plane, it's the pilot.

                      Comment


                      • Apples to oranges.

                        What he was getting at was that the 447 crew was out of the loop due to design.

                        Not to mention day versus night and he did have a panel to work with. He sure had talent and ... a pile of luck and fate was stacked with him that day.

                        The question he did dodge in a subtle way was the age issue but his implication was that the system and ergonomics must be with the person flying ... not age as a factor. I have been up with a few old pilots that I would not go with again .... age indeed, good reflexes on his part.
                        Live, from a grassy knoll somewhere near you.

                        Comment


                        • Sully wasn't flying across the equator far out over the ocean. Stop trying to make hay out of the details. He was making a general point that I consider incontrovertible. They call it "human factors", something considered marginal by those who glory in technical issues.

                          Comment


                          • Originally posted by guamainiac View Post
                            Apples to oranges.

                            What he was getting at was that the 447 crew was out of the loop due to design.

                            Not to mention day versus night and he did have a panel to work with. He sure had talent and ... a pile of luck and fate was stacked with him that day.
                            Yeah, all the AF447 pilots got was immediate stall warnings and a clear indication of unreliable airspeed and alternate law within 10 seconds. Clearly out of the loop. I mean, all Sully had to do was somehow extend the glide, make a quick call on where to put it down and execute a landing on a river, whereas these guys had to set the thrust to CLB and the pitch to 5° and... calmly run through the QRH checklist when they had a few seconds, but, hey, that's a lot to deal with in an uncontrollable roboplane with a mind of its own.

                            Hey this is fun.

                            Comment


                            • Evan, you really lowered the quality of your postings with the Sully comment dude! For your own benefit, I'll pretend from now on that you didn't even made it
                              Had Sully had that emergency occur somewhere else, in slightly different circumstances, even if he was Chuck Yeager the outcome may have been a complete tragedy. I think Captain Sullenberger and Jeff Skiles are incredible pilots, and they deserve admiration for their great work, but had that scenario had occurred taking off from Juliaca, in Peru, and they had landed in the Titicaca lake at night, they'd be all dead right about now. Mind you, they had a dual engine failure, which is completely different beast to deal with than that the AF pilots had in their hands.
                              Evan, you remind me of someone btw

                              Comment


                              • Complex quote:

                                "After stalling, the A330's angle of attack stayed above 35°. But while this exceeded the threshold for the abnormal attitude law, the flight control computers had already rejected all three air data reference units and all air data parameters owing to discrepancy in the airspeed measurements."
                                But I question this because if this is true, how were they still getting stall warnings...?
                                I wouldn't know, but perhaps the thing that said that the AOA was above 35 degrees might have some input?

                                Oh crap, my bad, stalls happen when you go too slow.
                                Les règles de l'aviation de base découragent de longues périodes de dur tirer vers le haut.

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