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Malaysia Airlines Loses Contact With 777 en Route to Beijing

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  • Satellite arcs

    It seems the last probable position (the two arcs) are based on data received via Inmarsat geostationary IOR satellite (aka Inmarsat 3 F1, position 64.5 east). I don't know the exact service used, but it's probably something using a low gain antenna, presumably the "Aero L" 600/1200 b/s service or something similar, using X.25-alike packet switching technology. The ability to provide estimate distance from the satellite means the service probably uses some sort of point-to-multipoint Time-Division Multiplexing (TDM/TDMA) which requires synchronizing multiple transmitters so the satellite receives all data packets in their assigned time frames. This is typically done using "Timing advance", calculated each time a connection is established. This calculation may be very precise, but the satellite may only get/use the most significant portion of the value, thus greatly reducing the precision.

    I don't really think the satellite adjusts its antennas to accommodate the next expected connection

    The reason the previous distances (arcs) are not available may be as simple as this: they (Inmarsat) possibly don't log each TA, but only store "current" (last) value in a record describing an active terminal. On the other hand, previous connections (attempts) are logged (without TA) for billing purposes.

    K.

    Comment


    • Originally posted by BlueMax View Post
      TERRAIN MASKING: It dropped to 5,000 feet after turning back from Kuala Lumpur-Beijing route on March 8
      If it was that low it couldn't have flown for anything like the distance and time previously estimated. Even without pressurisation nobody would typically fly a jet at that altitude, because of the fuel consumption.
      Which may be good news if it means the "pings" from the engine monitoring system occured after could not possibily have still been flying.

      Comment


      • Does anyone know, wheather the FDR and CVR of a 777 can be switched off (from the cockpit)?
        Ciao,
        Jason

        Comment


        • Originally posted by BoeingBobby View Post
          And just how long was this A/C flying at 5000' These comments are just ridiculous. The airplane would burn so much fuel at that altitude that the range we be cut by more than 3/4. So this airplane flew around at 5000' and still had enough fuel to make a clandestine landing in the Middle East.
          ROTFLMFAO! Oh wait, maybe they had a KC-135 or KC-10 all set up for the air to air. Oh that's no good can't do that in a 777 can you!!!
          A T7 refitted for in flight refueling is about as likely as one refitted with extra fuel tanks. (Though in that case where would the pax and cargo go? AFAIK Boeing never actually built the KC-777.)

          There's no way this plane could possibly get that far flying at FL50.
          Potentially possible at FL450, assuming the plane can acually fly above its certification ceiling.

          Comment


          • Originally posted by Jason View Post
            Does anyone know, wheather the FDR and CVR of a 777 can be switched off (from the cockpit)?

            No, and this has already been addressed earlier in the thread.

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            • I can not believe that this thread has turned into a political and psychological debate. I withdraw from any further discussions on anything that is not related to aviation.

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              • Originally posted by mpe View Post
                A T7 refitted for in flight refueling is about as likely as one refitted with extra fuel tanks. (Though in that case where would the pax and cargo go? AFAIK Boeing never actually built the KC-777.)

                There's no way this plane could possibly get that far flying at FL50.
                Potentially possible at FL450, assuming the plane can acually fly above its certification ceiling.
                You are kidding me right? Did you not read my post for what it is?

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                • This may make me appear a bit "senior", apologies for that. However, as many posts are stating the difficulty in flying undetected past India and Pakistan on the north-westerly route, and providing that was the plan, I would propose a diversion maneuver and then going north across the Gulf of Thailand and attempt to cross Cambodia, who would have a rather weak network of radar and air defence. (apologise again, I do not wish to be patronizing!)
                  It would not be totally unrealistic to believe that the last "ping" was on the outside of the 40° beam radius, placing the aircraft over land in north-west Laos, or even Burma, who incidentally do not have a whole lot of advanced air search radars either. I suspect that the beam pattern of the Inmarsat antenna array is not so well defined at the skirts, so the radii drawn on the scanned paper map previously posted here may have larger errors to them than we wish or hope. This may be the reason why there´s no debris field in the suggested flight path.
                  Hence, in my opinion, they could well be looking in the wrong place.
                  The ideas of the forum on this will be interesting to read.

                  Comment


                  • The question was how could anyone be indifferent to the lives of 239 passengers. I find it easy to understand that indifference. It isn't all that rare in this world. I'd hope apocalypse is irrelevant, but the suicide theory is precisely an apocalypse, a personal one where a plane full of living beings gets punished for one person's despair. I wasn't by any stretch the person who mentioned the suicide theory. I just don't get why anyone is puzzled by the thought of 239 lives being nothing.

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                    • Originally posted by Passion for flying View Post
                      This may make me appear a bit "senior", apologies for that. However, as many posts are stating the difficulty in flying undetected past India and Pakistan on the north-westerly route, and providing that was the plan, I would propose a diversion maneuver and then going north across the Gulf of Thailand and attempt to cross Cambodia, who would have a rather weak network of radar and air defence. (apologise again, I do not wish to be patronizing!)
                      It would not be totally unrealistic to believe that the last "ping" was on the outside of the 40° beam radius, placing the aircraft over land in north-west Laos, or even Burma, who incidentally do not have a whole lot of advanced air search radars either. I suspect that the beam pattern of the Inmarsat antenna array is not so well defined at the skirts, so the radii drawn on the scanned paper map previously posted here may have larger errors to them than we wish or hope. This may be the reason why there´s no debris field in the suggested flight path.
                      Hence, in my opinion, they could well be looking in the wrong place.
                      The ideas of the forum on this will be interesting to read.
                      The question that comes up here is: where were they going? If they intended to land in Thailand, Burma, Laos or Cambodia, you might be right. (The question then still remains: why steal a 200mio-$ aircraft including 238 other people and then land with them somewhere in Southeast Asia?)
                      If they intended to continue on beyond Southeast Asia, they would have to pass through either Indian or Chinese air space, and I am pretty certain that would have called a few Sukhois to be their escort.

                      Comment


                      • Originally posted by EconomyClass View Post
                        The question was how could anyone be indifferent to the lives of 239 passengers. I find it easy to understand that indifference. It isn't all that rare in this world. I'd hope apocalypse is irrelevant, but the suicide theory is precisely an apocalypse, a personal one where a plane full of living beings gets punished for one person's despair. I wasn't by any stretch the person who mentioned the suicide theory. I just don't get why anyone is puzzled by the thought of 239 lives being nothing.
                        Hmmmmm... have you watched the news lately? That should answer your question. Beyond that, I'd prefer to keep this thread to the aviation aspects of this affair. Anybody interested in discussing the morals or psychology involved will probably find plenty of forums concerned with that out there in the world-wide web (or at least take the discussion to the off-topic forum of jetphotos.net).

                        Comment


                        • Originally posted by Peter Kesternich View Post
                          The question that comes up here is: where were they going? If they intended to land in Thailand, Burma, Laos or Cambodia, you might be right. (The question then still remains: why steal a 200mio-$ aircraft including 238 other people and then land with them somewhere in Southeast Asia?)
                          If they intended to continue on beyond Southeast Asia, they would have to pass through either Indian or Chinese air space, and I am pretty certain that would have called a few Sukhois to be their escort.
                          Well, that part of the puzzle still bothers me, too. Where to go and for what purpose-? I have tried to ignore those questions, as I am not very good at understanding the criminal mind. I am sure once once we figure out where the aircraft ended up landing, we will probably hear a story that will make our ears curl...

                          I am just offering my opinion based on some knowledge of radars and microwave stuff. There may be better qualified people around who will challenge my ideas, and that will make for a good debate!

                          BTW, I checked the books for the existence of any air to air missiles of dignity in Cambodia, and they seem not to have anything that would bring down this size of aircraft in the middle of the night.

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                          • It could have landed relatively close to the coast and still be pinging within the arc. Again as mentioned earlier looking at the earlier pings to the satellite should help.

                            Going piggyback on another 777 to avoid rather sounds a bit far fetched to me, I find it more realistic to think it was either ditched in the indian ocean or it landed on a country with poor radar coverage.
                            AD.com apocalypse survivor. 727 Fan.

                            Comment


                            • Originally posted by sjwk View Post
                              News on the radio this morning said that a flight engineer who was travelling as a passenger was being investigated, although not found anything online to cite (in admittedly 30 seconds of looking). Then again I imagine they're investigating *every* passenger..
                              What's a 'flight engineer"?

                              Comment


                              • Originally posted by Evan View Post
                                What's a 'flight engineer"?
                                He used to be the third man in the cockpit. Believe it or not, there are still aircraft out there with a three-person crew, especially cargo-carrying 747 classics as well as 727s.

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