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Lion Air 737-Max missing, presumed down in the sea near CGK (Jakarta)

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  • #31
    Originally posted by Chris K View Post
    Definitely agree on #2 in that we don't want any loss of life. What I was thinking in terms of mitigation was that the test crew would be of the sort where they are somewhat used to high risk situations and therefore able to cope with any abnormalities much better than a regular line pilot. Makes me wonder who get picked to make the test flights when planes do come out of major maintenance events - are they specially trained and come from the manufacturer (Boeing, AirBus, ...) or does the carrier just draw lots and pick the lucky pair?
    Who told you that the job done or required on this plane involved "major maintenance events"?

    --- Judge what is said by the merits of what is said, not by the credentials of who said it. ---
    --- Defend what you say with arguments, not by imposing your credentials ---

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    • #32
      Originally posted by Gabriel View Post
      Who told you that the job done or required on this plane involved "major maintenance events"?
      I was speaking generically - curious who does the test flight for events that all would agree are "major".

      Comment


      • #33
        Originally posted by Chris K View Post
        Thanks everyone for your answers! I guess it brings me to the rather obvious question which is whether an incident the day prior to this accident should have necessitated a test flight. Unless I've got Capt. Sulley or Boeing's test pilot version of Neil Armstrong flying, I'd sure much rather have been the 2nd flight out after the maintenance than the first for the simple reason that, say what you will, unless the plane is airborne I'm not sure you could convince me you're 100% sure this problem has been fixed.

        The general consensus that every professional pilot should be able to handle this dealt hand doesn't really cut it with me for the simple reason that A. Whether or not this turns out to be what actually caused the accident remains to be seen, but it is certainly true that this type of issue has been known to throw pilots a big curve ball they don't always handle, and B. Just as in every other profession there are great, good, average, and bad levels of skill and the flight after a maintenance event that corrected an issue with critical data inputs is the day I'd rather have seen someone take the bird up for a spin before loading up with pax and crew. I would bring the maintenance person and their supervisor along for the check ride - extra motivation that they get the repair right the first time.
        As far as I can tell, the previous flight had experienced an unreliable airspeed event. These tend to be transient, caused by meteorological phenomena, and leave no evidence. Ground maintenance can test everything, and even replace things that test ok as an added measure of caution, but chances are they will find nothing wrong. If, on the other hand, the event was caused by flight control issues and the problem cannot be replicated or detected on the ground and identified as an LRU issue(s), that aircraft needs to be removed from service, ferried back to a maintenance base and sorted out (the ferry flight being the first 'test fight'). We still don't know what the previous flight issue was and if it had anything to do with this crash.

        The general consensus that every professional pilot should be able to handle this dealt hand doesn't really cut it with me...
        Then you should give up flying, because this is what it comes down to and every professional pilot should be able to handle most failures that occur either by memorized procedure or by CRM using the cockpit resources. The main thing is that every professional pilot should be able to first stabilize the aircraft, not exacerbate the situation by erroneous commands, and then remain stabilized while working the problem. Yes, not all pilots are equal, but this must be the training standard that all pilots must meet. And yes, there are human factors that can cause these erroneous commands, but CRM procedures are written to overcome these factors and they must be learned and faithfully executed. The single biggest reason we still see these inexplicable crashes is that pilots and operators are still resisting or neglecting to embrace these measures. There is too much hubris and corner-cutting going on within certain pilot/operator/CAA cultures.

        There are almost no in-flight system failures that a competent crew can't fly out of. That includes flight control computer issues, even FBW ones. Modern aircraft are designed to selectively degrade down to the most basic flight control if needed. But that doesn't help if the crew isn't trained in that respect.

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        • #34
          Info on the logs from the previous flight

          https://theaircurrent.com/aviation-s...-social-media/

          Comment


          • #35
            Originally posted by 3WE View Post
            I am pretty sure there are somewhat complex and robust procedures and “thresholds” as to exactly how you test a repair.

            Am I correct?
            Gabe is not going to like this reply but, this is one of the times that if you have never been a line pilot for a 121/135 carrier, is hard to understand. Again, look up MEL, DDG, DMI.

            Comment


            • #36
              Originally posted by BoeingBobby View Post
              Gabe is not going to like this reply but, this is one of the times that if you have never been a line pilot for a 121/135 carrier, is hard to understand. Again, look up MEL, DDG, DMI.
              Look, the concern was about whether a ground repair alone can sufficiently assure that a repair has been successful (and that the problem has been allieviated by that repair). DDG et. al. is a different issue.

              Chris: In order to be dispatched for passenger service, every commercial airliner has to be in a condition that meets the airworthiness requirements under which the aircraft was type certified. The DDG (MEL and CDL) assure that this is the case and do not deviate from that requirement.

              The part of this that might be relevant here is the MEL (Minimum Equipment List). This is an operator-specific manual that lists all the equipment that can be inoperative while still allowing the airplane to remain in service. Often, it includes requirements stating that, if one component is inoperative, another must be functioning, and/or limits the number of flight cycles that can be performed in the indicated condition. It is derived from the manufacturer's MMEL (Master Minimum Equipment List) which was used to certify the aircraft. The MMEL determines instruments and equipment that are either specifically or otherwise required by the airworthiness requirements under which the aircraft is type certificated and which are essential for safe operations under all operating conditions. The MEL can not be less restrictive than the MMEL. In short, as long as the aircraft meets the requirements of the MEL, it can be flown safely by competent pilots.

              There are some important caveats: The inop components must be properly flagged, entered into the maintenance log, and the pilots must be fully aware of the conditions. The level of equipment redundancy may also be reduced or (in the case of less-essential components) eliminated.

              What is interesting here is that there was a technician on board this flight. The company has stated that this is a standard precaution on new aircraft. Perhaps it had nothing to do with the condition of the aircraft or the crash. But it makes you wonder if a repair was made (or a fault could not be replicated and indentified after the previous flight) that left some doubt about the dispatch safety of the aircraft, and that this might have constituted a 'test flight' in itself.

              The only reason I would raise that suspicion is the history of the Indonesian aviation safety culture. In April 2007, the FAA downgraded Indonesia to Category 2 in its International Aviation Safety Assessment program. Category 2 means the nation does not meet ICO standards for aviation safety enforcement and compliance. They restored that to Category 1 in 2016 after certain reforms were made, but culture runs deep. And, last I checked, the EU continues to have a ban on all but five Indonesian carriers.

              So the DDG, the CDL and the MEL, are all pretty useless if the operator or its personnel are not abiding by them. It comes down to this.

              Comment


              • #37
                Originally posted by Evan View Post
                Look, the concern was about whether a ground repair alone can sufficiently assure that a repair has been successful (and that the problem has been allieviated by that repair). DDG et. al. is a different issue.

                Chris: In order to be dispatched for passenger service, every commercial airliner has to be in a condition that meets the airworthiness requirements under which the aircraft was type certified. The DDG (MEL and CDL) assure that this is the case and do not deviate from that requirement.

                The part of this that might be relevant here is the MEL (Mininum Equipment List). This is an operator-specific manual that lists all the equipment that can be inoperative while still allowing the airplane to remain in service. Often, it includes requirements stating that, if one compenent is inoperative, another must be functioning, and/or limits the number of flight cycles that can be performed in the indicated condition. It is derived from the manufacturer's MMEL (Master Minimum Equipment List) which was used to certify the aircraft. The MMEL determines instruments and equipment that are either specifically or otherwise required by the airworthiness requirements under which the aircraft is type certificated and which are essential for safe operations under all operating conditions. The MEL can not be less restrictive than the MMEL. In short, as long as the aircraft meets the requirements of the MEL, it can be flown safely by competent pilots.

                There are some important caveats: The inop components must be properly flagged, entered into the MEL report, and the pilots must be fully aware of the conditions. The level of equipment redundancy may also be reduced or (in the case of less-essential components) eliminated.

                What is interesting here is that there was a technician on board this flight. The company has stated that this is a standard precaution on new aircraft. Perhaps it had nothing to do with the condition of the aircraft or the crash. But it makes you wonder if a repair was made (or a fault could not be replicated and indentified after the previous flight) that left some doubt about the dispatch safety of the aircraft, and that this might have constituted a 'test flight' in itself.

                The only reason I would raise that suspicion is the history of the Indonesian aviation safety culture. In April 2007, the FAA downgraded Indonesia to Category 2 in its International Aviation Safety Assessment program. Category 2 means the nation does not meet ICO standards for aviation safety enforcement and compliance. They restored that to Category 1 in 2016 after certain reforms were made, but culture runs deep. And, last I checked, the EU continues to have a ban on all but five Indonesian carriers.

                So the DDG, the CDL and the MEL are all pretty useless if the operator or its personnel are not abiding by them. It comes down to this.
                If you say so....

                Comment


                • #38
                  Originally posted by Evan View Post
                  What is interesting here is that there was a technician on board this flight. The company has stated that this is a standard precaution on new aircraft. Perhaps it had nothing to do with the condition of the aircraft or the crash. But it makes you wonder if a repair was made (or a fault could not be replicated and indentified after the previous flight) that left some doubt about the dispatch safety of the aircraft, and that this might have constituted a 'test flight' in itself.
                  Yes, some might think that. However, if I were worried about the safety, I would order the aircraft out of service until I was happy it was safe to fly even with test pilots. If I were trying to track down an intermittent problem that did NOT affect safety, then I would send the technician on the flight.

                  Comment


                  • #39
                    Originally posted by BoeingBobby View Post
                    If you say so....
                    Go on...

                    Comment


                    • #40
                      Originally posted by Schwartz View Post
                      Yes, some might think that. However, if I were worried about the safety, I would order the aircraft out of service until I was happy it was safe to fly even with test pilots. If I were trying to track down an intermittent problem that did NOT affect safety, then I would send the technician on the flight.
                      But what of the extent of the problem is yet unknown, or if the casual chain of events that leads to an unsafe condition weren't fully considered, or if a technically "safe" condition becomes unsafe in the wrong hands (often the case in aviation disasters)...

                      Comment


                      • #41
                        Originally posted by BoeingBobby View Post
                        Gabe is not going to like this reply but, this is one of the times that if you have never been a line pilot for a 121/135 carrier, is hard to understand. Again, look up MEL, DDG, DMI.
                        No, it's ok. Maintenance procedures and practices are not my strong points. Now, I am sure that there are other ways to understand it other than being a pilot for a 121/135 carrier. What about being in the maintenance, quality control, or engineering department of a 121/135 carrier?

                        And since you are a (retired) 121/135 pilot, perhaps you can be more constructive and help expand our understanding on the subject.
                        I was almost hoping that would chime in and say "Gabriel (or Evan or 3WE) is wrong because in fact it works like this: ______".

                        --- Judge what is said by the merits of what is said, not by the credentials of who said it. ---
                        --- Defend what you say with arguments, not by imposing your credentials ---

                        Comment


                        • #42
                          The accident just claimed 1 additional victim. A diver died.
                          On Nov 3rd 2018 Indonesia's Navy reported a volunteer diver recovering body parts died, probably because of decompression. The diver had served in AirAsia Indonesia's crash QZ-8501 four years ago, and in Palu after the September 2018 earthquake and tsunami.
                          http://avherald.com/h?article=4bf90724&opt=0

                          Raw images of the underwater search and recovery: what divers see

                          WARNING: I was made aware by a forum mate that this video contains images of human body parts, something that I didn't know or recognized.
                          Viewer discretion is STRONGLY advised. Click at your own risk

                          https://www.youtube.com/watch?v=v2m5b8NFbfI

                          --- Judge what is said by the merits of what is said, not by the credentials of who said it. ---
                          --- Defend what you say with arguments, not by imposing your credentials ---

                          Comment


                          • #43
                            Originally posted by Gabriel View Post
                            No, it's ok. Maintenance procedures and practices are not my strong points. Now, I am sure that there are other ways to understand it other than being a pilot for a 121/135 carrier. What about being in the maintenance, quality control, or engineering department of a 121/135 carrier?

                            And since you are a (retired) 121/135 pilot, perhaps you can be more constructive and help expand our understanding on the subject.
                            I was almost hoping that would chime in and say "Gabriel (or Evan or 3WE) is wrong because in fact it works like this: ______".
                            I have thinking about it. Back is f'd up and hard to sit very long at the computer. You are right about anyone that would be in "maintenance control" for a carrier. Even dispatchers would have a pretty good background.

                            Comment


                            • #44
                              I don’t care what the procedures are for test drives- there’s only two questions relevant: 1. Were procedures followed and 2. Regardless of procedures, would a test drive likely changed the outcome?
                              Les règles de l'aviation de base découragent de longues périodes de dur tirer vers le haut.

                              Comment


                              • #45
                                Here is a major problem where someone picks up the recorder.
                                The box must be kept under water in case its seals were damaged, so it can be properly cleaned and decontaminated by experts.
                                https://www.youtube.com/watch?v=PX67McESfLY

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