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  • Originally posted by WhiteKnuckles View Post
    This plane dropped out of the sky on 6/1. It is now 7/8. Is that enough of an answer? I'd say "listening" at this point may be past its useful life.
    Errr, yes, I agree. So do the authorities aparently as they have called off the search for the pingers on the 4th of this month. Another search using different equipment will be apparently starting on the 10th - I posted a link a few days back. The first week or so the search wasn't for the pingers, rather it was initially a survivor search, then a body and debris search. The equipment to locate the pingers and the french sub would have taken at least a week to get out onto the crash scene and they are probably searching the seafloor with an area the size of Wales.

    The fact that the pingers were not located by the sub (or anyone else for that matter) does not mean that that wasn't a good idea to send the sub. Now that we can reasonably assume the pingers didn't work or are beyond the range of the listening gear and the batteries have died, now is the time to bring in the ROV's and sidescan sonars etc - which is what the authorities are probably doing right now.

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    • Originally posted by Leightman View Post
      I appreciate your effort in this explanation, but I don't know how one could increae to full pwer and then the nose down, and not overspeed.
      Of course not. The plane would overspeed and that's the source of the lost of control.

      What I meant (and said) is that the INDICATED airspeed won't increase, not because the plane is not going faster but because the pitots are clogged, and hence the airspeed indication is false 8and hence there will be no overspeed warning even when the plane will be overspeeding).

      As I've said, it happened before.

      An Austral DC-9-32 got iced pitots.
      The indicated airspeed started to go down (the real speed had not changed).
      The pilots applied more power.
      The indicated airspeed kept coming down (the real speed started to increase).
      The pilot nosed down to gain airspeed.
      The indicated airspeed kept going down (the real airspeed kept going up).
      The pilots thought they were about to stall due to the very low airspeed (the plane was not about to stall,actually it was already overspeeding).

      Up to this point, we could have a match with the AF case. The Austral case went on as this:

      The pilots extended the slats at a speed that, far from being the very slow and close to stall as indicated in the faulty instruments, was very high and way beyond the slats limitations.
      One slat element failed, they lost roll control and that's was it. The plane impacted in one piece (save for the slat element that failed) almost vertical and at nearly the speed of sound.

      Of course this not how the AF case ended, but it could be how it started.

      --- 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


      • Nose down trading alt for speed

        Originally posted by Gabriel View Post
        Of course not. The plane would overspeed and that's the source of the lost of control.

        What I meant (and said) is that the INDICATED airspeed won't increase, not because the plane is not going faster but because the pitots are clogged, and hence the airspeed indication is false 8and hence there will be no overspeed warning even when the plane will be overspeeding).

        As I've said, it happened before.

        An Austral DC-9-32 got iced pitots.
        The indicated airspeed started to go down (the real speed had not changed).
        The pilots applied more power.
        The indicated airspeed kept coming down (the real speed started to increase).
        The pilot nosed down to gain airspeed.
        The indicated airspeed kept going down (the real airspeed kept going up).
        The pilots thought they were about to stall due to the very low airspeed (the plane was not about to stall,actually it was already overspeeding).

        Up to this point, we could have a match with the AF case. The Austral case went on as this:

        The pilots extended the slats at a speed that, far from being the very slow and close to stall as indicated in the faulty instruments, was very high and way beyond the slats limitations.
        One slat element failed, they lost roll control and that's was it. The plane impacted in one piece (save for the slat element that failed) almost vertical and at nearly the speed of sound.

        Of course this not how the AF case ended, but it could be how it started.
        Austral DC9 was pretty hard core and old equipment. Would you agree that the AF captain with 10000 hours under his belt, when pitching nose down would still believe any instrument telling him he is actually slowing? I dont think so. And, others please comment, I believe that your windshield noise and maybe other vibration indicators pretty much will alert basic instincts that the AB330 is overspeeding, after all the speed jump does not happen in only one second, it builds, if at all, up. Last item, question to all, how do N1 and N2 readouts, levels help in case of confusion?

        Comment


        • Last item, question to all, how do N1 and N2 readouts, levels help in case of confusion?
          Power + Attitude = Performance.

          If the aircraft is being flown at its usual attitude for cruise, then if you have the correct thrust set, then the speed looks after itself.

          If you have lost your airspeed indicators, then by setting the engines to a certain power setting, and then setting the aircraft to a corresponding pitch attitude, you can fly quite safely.

          There are tables on the aircraft that show appropriate pitch and thrust settings for an airspeed unreliable situation for different weights and altitudes.

          Would you agree that the AF captain with 10000 hours under his belt, when pitching nose down would still believe any instrument telling him he is actually slowing?
          Yes, it is entirely possible that he would. On a dark, stormy night, when the instruments start telling you conflicting information, you have a tough time ahead of you, especially given the recent flight control/attitude indicator issues suffered by another carrier would have been fresh in their mind.

          The theory that you would notice the overspeed from a higher windshield noise etc is valid, however if your instrumentation is telling you different things, then it can be an extremely confusing situation. Your training is designed around trusting the instruments at all times, and ignoring the somatogravic effects. When those instruments go awry it can be very disorienting until you sort out in your mind exactly what is happening.

          Comment


          • Originally posted by swissair View Post
            Austral DC9 was pretty hard core and old equipment. Would you agree that the AF captain with 10000 hours under his belt, when pitching nose down would still believe any instrument telling him he is actually slowing? I dont think so. And, others please comment, I believe that your windshield noise and maybe other vibration indicators pretty much will alert basic instincts that the AB330 is overspeeding, after all the speed jump does not happen in only one second, it builds, if at all, up. Last item, question to all, how do N1 and N2 readouts, levels help in case of confusion?
            If you asked me, I don't understand how the Austral pilots (which were highly experienced too, no teenager commuter pilot there) missed that if the pitch was just a couple of degrees above the horizon, and if the altitude was constant, then the AoA was just a couple of degrees, and hence they were nowhere close to stall, no matter what the airspeed (indicated or real) was.

            But it happened.

            A lot of accidents are the same from this point of view. You end up wondering what the hell were they doing or thinking?

            Was this the case here? I have no idea. Is it likely that something like that could happen? No. But no matter what the sequence of event was, it will be a highly unlikely one. Otherwise it wouldn't be the first time in 15 years of service with more than 1 million flights and 10 million hours flown on this type's fleet.

            In any case, I've already said it is a scenario that I don't want to even call it "a theory".

            --- 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


            • Originally posted by SYDCBRWOD View Post
              Errr, yes, I agree. So do the authorities aparently as they have called off the search for the pingers on the 4th of this month. Another search using different equipment will be apparently starting on the 10th - I posted a link a few days back. The first week or so the search wasn't for the pingers, rather it was initially a survivor search, then a body and debris search. The equipment to locate the pingers and the french sub would have taken at least a week to get out onto the crash scene and they are probably searching the seafloor with an area the size of Wales.

              The fact that the pingers were not located by the sub (or anyone else for that matter) does not mean that that wasn't a good idea to send the sub. Now that we can reasonably assume the pingers didn't work or are beyond the range of the listening gear and the batteries have died, now is the time to bring in the ROV's and sidescan sonars etc - which is what the authorities are probably doing right now.
              I guess because so many airlines are close to being broke, that's why necessary equipment takes a week to arrive. But maybe this crash suggests a need to sign treaties to allow pulling useable equipment from maybe a DAY away? When I served in the coast guard, way way back, I sailed on a ship stationed in the middle of the Pacific Ocean. I think it was three weeks we maintained a nearly fixed position. Reason? To be within hours of a plane downed flying from the mainland to Hawaii. It wasn't the airlines that did this, it was Treasury Department, through the US Coast Guard. I'm quite certain we would have searched for survivors or equipment belonging to any nation. I can't tell you if ocean station vessels still sail to that place, but it was a rational thing to do. But now that I think it, amphibious planes exist. Why couldn't several of those or if there are pontoon equipped helicopters, send those. The notion of putting a sub to sea AFTER concluding the plane is lost is kinda Johnny-come-lately. Guess I won't be flying routes with so little prep for disasters.

              Comment


              • Originally posted by Gabriel View Post
                Of course not. The plane would overspeed and that's the source of the lost of control....Up to this point, we could have a match with the AF case. ...The pilots extended the slats at a speed...Of course this not how the AF case ended, but it could be how it started.
                You have a match with Austral only until the mistaken slat deployment. My point is that I don't think you can begin the scenario sequence not far from overspeed, and from there go overspeed, and then lose control, and that's the start of things. If you go overspeed and lose control and stay out of control (on alternate law no less), you will either overstress thje A/C due to pilot input, or some important part of the airplane most likely will just give up and fall apart. You just can't go overspeed and stay there, out of control, overspeed, but not increasing in speed, and remain intact, in probable turbulence, for a long time. I suppose it is possible, but I think it very unlikely. That they crashed tells us they were out of control for a while, but the nose-up impact tells us that they overcame their disorientation, had regained control, and were most likely trying to pull out of the dive. If true they almost made it.

                I think we have learned a lot in the past two weeks, even though huge questions remain. We know they had trouble with flight data instruments, though we don't know why. They were probably overwhelmed with conflicting information and lost control as a result. They certainly did lose control and a lot of altitude as a result. They apparently didn't break anything on the way down.

                The two biggest questions for me now are what caused the erroneous instrumentation (and I am finding myself more open to Evan's pitot problem, though icing may not be the ultimate cause), and even more important, what caused the large cascade of problems including loss of the main displays. A few people have stated the airspeed disagree could cause some cascade, and I can see that. But if the cascade could extend and grow all the way to knocking out the main flight data displays, then we have a much bigger problem than pitots.

                Comment


                • Originally posted by WhiteKnuckles View Post
                  I guess because so many airlines are close to being broke, that's why necessary equipment takes a week to arrive. But maybe this crash suggests a need to sign treaties to allow pulling useable equipment from maybe a DAY away? When I served in the coast guard, way way back, I sailed on a ship stationed in the middle of the Pacific Ocean. I think it was three weeks we maintained a nearly fixed position. Reason? To be within hours of a plane downed flying from the mainland to Hawaii. It wasn't the airlines that did this, it was Treasury Department, through the US Coast Guard. I'm quite certain we would have searched for survivors or equipment belonging to any nation. I can't tell you if ocean station vessels still sail to that place, but it was a rational thing to do. But now that I think it, amphibious planes exist. Why couldn't several of those or if there are pontoon equipped helicopters, send those. The notion of putting a sub to sea AFTER concluding the plane is lost is kinda Johnny-come-lately. Guess I won't be flying routes with so little prep for disasters.
                  Can you please explain why, given the pingers have a 30 day life why we need to have equipment expensively duplicated and stationed all around the globe to achieve your proposed turnaround times? Pingers and pinger locators are not going to save your life. Are you confusing this device with an EPIRB? The sole reason why the pingers are fitted is to enable the 'black boxes' to be located underwater. If they are needed it's because the plane has crashed, and investigators are trying to find out why. Where is the emergency in that? This has nothing to do with search and rescue.

                  It has nothing to do with airlines going broke - I don't know this to be true, but I'm fairly sure that the BEA, or if the problem was in American waters, the NTSB, (government agencies) will charter the necessary airframes to get their pinger locators to the scene. So if anything the freight carriers are going to be making money out of this. The equipment is operated off a ship of some description. The agency in charge has to find a suitable vessel for charter that has the required equipment handling davits etc, plus no doubt deck space for the control container etc, plus the exportable electrical power, cruise out to the suspected site and start searching. Unless you are inordinately fond of paying taxes, it's fine by me to have say one or two teams of well trained professionals stationed at a couple of places around the globe, and fly them to where they are needed (as they do now). Or we can have every country on the globe with a coastline maintain a specialised set of skills and expensive equipment that may get used once every 50 years - your choice. If you elect the latter I'll be asking NASA to be in the first batch of moon colonists - I pay enough tax.

                  Comment


                  • Unless you are inordinately fond of paying taxes, it's fine by me to have say one or two teams of well trained professionals stationed at a couple of places around the globe, and fly them to where they are needed (as they do now). Or we can have every country on the globe with a coastline maintain
                    Ummm. So they don't have the boxes. So the status quo does not work. You tell ME what would work. Seems like you're dedicated to shooting down the notion that change is necessary. But I think you'll concede that right now, everybody is relegated to guesswork because little if anything that will answer the key questions has been found, DESPITE the 30-day batteries that are in the boxes. I think your answer is "no answer". Every alternative is ridiculous. Despite the example set decades ago when the American governmennt did EXACTLY the thing that you think is ridiculous to contemplate.

                    What exactly are you defending? Do you know?

                    Comment


                    • Overspeed, AOA N1 settings

                      Originally posted by MCM View Post
                      Power + Attitude = Performance.

                      If the aircraft is being flown at its usual attitude for cruise, then if you have the correct thrust set, then the speed looks after itself.

                      If you have lost your airspeed indicators, then by setting the engines to a certain power setting, and then setting the aircraft to a corresponding pitch attitude, you can fly quite safely.

                      There are tables on the aircraft that show appropriate pitch and thrust settings for an airspeed unreliable situation for different weights and altitudes.



                      Yes, it is entirely possible that he would. On a dark, stormy night, when the instruments start telling you conflicting information, you have a tough time ahead of you, especially given the recent flight control/attitude indicator issues suffered by another carrier would have been fresh in their mind.

                      The theory that you would notice the overspeed from a higher windshield noise etc is valid, however if your instrumentation is telling you different things, then it can be an extremely confusing situation. Your training is designed around trusting the instruments at all times, and ignoring the somatogravic effects. When those instruments go awry it can be very disorienting until you sort out in your mind exactly what is happening.
                      Thanks, then you would agree that a captain of AF with all his drills and emergency sim sessions on this type would have resorted to the "manual" setting of N1 combined with the appropriate alt and weight tables as recommended in the manual of AB330? I mean, they are very well trained at AF with loads of extra courses, like their peers LH and BA, amongst the best trainings of all. And, I know this from other well experienced pilots, they have to think laterally as it happened so many times that instruments failed or were faulty on the readouts. Too many times, sadly. That then points at least in this direction of a sudden hefty situation shift to the worst, sudden impact, failure of some structural or control surface element. At thi stage it could also have been an uncommanded one sided slat extension, that would flip the plane over in not time and rip things apart at M 0.83 would it not? Or a one sided Thrust reverser deploying uncommanded, such kindof sudden failures. (Lauda Air004: Lauda Air Flight NG004 was a scheduled service from Hong Kong (HKG) back to Vienna (VIE), Austria. An intermediate stop was made in Bangkok (BKK), Thailand. The flight departed Bangkok at 23:02 hours. Some five minutes after takeoff the pilot-in-command stated "that keeps coming on," referring to a REV ISLN advisory warning. This indication appears when a fault has been detected in the thrust reverser system. The crew discussed the REV ISLN indication for about four and one-half minutes. The co-pilot read information from the Airplane Quick Reference Handbook as follows: "Additional systems failures may cause in- flight deployment" and "Expect normal reverser operation after landing." The pilot-in-command remarked "....its not just on, its coming on and off," he said, "...its just an advisory thing...," and shortly thereafter stated, "could be some moisture in there or something." At 23:12, the co-pilot advised the pilot-in-command that there was need for, "a little bit of rudder trim to the left." Fifteen minutes and one second into the flight the co-pilot exclaimed, "ah reverser's deployed," accompanied by sound similar to airframe shuddering, sounds of metallic snaps and the pilot-in-command stating "here wait a minute." With the deployment of the nr.1 engine thrust reverser, engine thrust was reduced to idle. Aerodynamic effects of the reverser plume in-flight during the engine run down to idle resulted in a 25 percent lift loss across the wing. The airplane stalled and entered an uncontrolled descent. Buffeting, maneuvering overload, and excessive speed caused pieces of the rudder and the left elevator to separate. This was followed by the down-and-aft separation of most of the right horizontal stabilizer from maneuvering overloads, as the crew attempted to control the airplane and arrest the high-speed descent. A torsional overload then caused the separation of the vertical and left horizontal stabilizers. The loss of the tail resulted in a sharp nose-over of the airplane, producing excessive negative loading of the wing. A downward wing failure was probably followed by the breakup of the fuselage. The complete breakup of the tail, wing, and fuselage occurred in a matter of seconds. The wreckage fell in mountainous jungle terrain.

                      PROBALE CAUSE: "The Accident Investigation Committee of the Government of Thailand determines the probable cause of this accident to be uncommanded in-flight deployment of the left engine thrust reverser, which resulted in loss of flight path control. The specific cause of the thrust reverser deployment has not been positively identified."

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                      • Ignore if this is old news...

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                        • Originally posted by WhiteKnuckles View Post
                          Right now, with the inability of ruling most stuff out, it is more educational as people raise different possibilities.
                          Educational indeed! Posters like Evan etc. assist greatly in explaining the various factors involved in keeping an a/c flying. I am sure technicians & engineers from Airbus (and pilots flying Airbus a/c) are also checking out the posts here (and maybe contributing too!).

                          PS: How about developing an airspeed sensor that is somehow embedded in the a/c windscreen, visible from the cockpit? Maybe a hollow glass tube with mercury inside some part of it...air rushing through the tube causes friction, i.e. heat that can be measured electronically and related to airspeed...

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                          • Use this forum to discuss aviation safety related incidents, accidents, and other aspects of aviation safety.


                            I wonder if AF447 and this A320 test flight crash near Perpignan could be related...

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                            • A320 vs A330

                              Originally posted by CockpitCat View Post
                              http://forums.jetphotos.net/showthre...ight=perpignan

                              I wonder if AF447 and this A320 test flight crash near Perpignan could be related...

                              They (320 and 330) are quite different in many aspects and also, the NZ A320 performed a high risk test at too low altitude where recovery was impossible. AF447 was at cruise FL 350.

                              Comment


                              • Originally posted by WhiteKnuckles View Post
                                Ummm. So they don't have the boxes. So the status quo does not work. You tell ME what would work. Seems like you're dedicated to shooting down the notion that change is necessary. But I think you'll concede that right now, everybody is relegated to guesswork because little if anything that will answer the key questions has been found, DESPITE the 30-day batteries that are in the boxes. I think your answer is "no answer". Every alternative is ridiculous. Despite the example set decades ago when the American governmennt did EXACTLY the thing that you think is ridiculous to contemplate.

                                What exactly are you defending? Do you know?
                                Just a sec here pal - who appointed you the presecutor? And why do you believe I am 'defending' anything? Just because I'm not leaping aboard your personal vendetta/paranoia that everybody in the aviation industry seems to be a fool and out to kill you doesn't mean I am necessarily on anybody's side.

                                Here's what I see:

                                1. In post 2484 you ask a pretty pointless question: "but is the search by these military subs just a futile delay in the search for the key pieces?"

                                The logic behind sending the SSN was sound - just because the sub didn't find the black boxes doesn't mean it was a 'futile delay'. 5 minutes spent reading the last few pages would have established that, so I tried to point out the stupidity of you question when I rephrased it.

                                2. In post 2487 you decided to ignore that or weirdly give an answer that had nothing to do with the question - and go off on a tangent: "This plane dropped out of the sky on 6/1. It is now 7/8. Is that enough of an answer? I'd say "listening" at this point may be past its useful life."

                                Again, if you had have read the past couple of pages you would know the answers to the questions you have just asked. Restating the obvious that 'listening is past its useful life' added nothing to the discussion. Again, I answered your questions.

                                3. Post 2496 you start some really weird shit blaming the airlines for delaying the sending of this equipment because they are broke, then getting into some really weird crap about being stationed on a coast guard cutter (which has absolutely no relevance to finding the black boxes). When I point this out and ask you why you consider it necessary to have a faster response you don't bother to answer. I particularly like this bit because it truely reveals you to be a nutter:

                                "The notion of putting a sub to sea AFTER concluding the plane is lost is kinda Johnny-come-lately."

                                So, let me get this straight, the sub that was deployed to help search for the black boxes should have been on station already? Do you have any idea what the conspiracy theorists would have made of that? "Hey it was just co-incidence that one of France's 6 SSN's and probably only one of 2 at sea wasn't shadowing enemy subs, it just happened to be at sea right under the flight path of a plane that fell out of the sky - and what luck, the captain had a set of orders to cover that exact contingency"

                                Or, should the French have built another 100 nuclear subs so they could have around 40 at sea at any one time on the off chance that an airliner may fall out of the sky. Do you think before typing this rubbish?

                                Your reply in post 2499 of course doesn't have any reply to the question I have asked about why it is so necessary to retrieve black boxes within one day (I can see the scenario now: Plane goes down, NTSB dispatches a seaplane with pinger locator because the french navy thoughtlessly had not positioned a sub nearby, plane lands amid wreckage and survivors in rafts. Plane crew shoot all the survivors because they got in the way of deploying the pinger locator, and their cries for help were creating too much noise to search effectively), but instead you start spraying about all sorts of other rubbish. I was not rubbishing the planeguard position, the question I had asked was how would having a coast guard cutter in the middle of the ocean assist in locating the pingers? Remember, we are talking about the recovery of inanimate objects here NOT THE PASSENGERS, but you seem to want to confuse SAR with a crash investigation.

                                Now to answer you question, I'm not defending anyone, just pointing out the logical flaws in nearly every statement you seem to post. Go ahead, keep asking inane questions, pretty soon you'll be ignored.

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