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Malaysia Airlines Loses Contact With 777 en Route to Beijing

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  • Originally posted by Dispatch Dog View Post
    Have we conclusively ruled out the possibility that it landed and refuelled somewhere?
    All such theories appeared to have been dropped after Inmarsat data were appearing. Probably a more scientific approach, much easier to defend. The airline and the government of Malaysia are having a tough time staying on top of this. In their situation it is probably best to keep with the available facts. Tomorrow will be an interesting day, indeed.

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    • Originally posted by starchyme View Post
      ...........He didn't describe the nature of the analysis."
      ...................they are telling.
      To explain it would probably require experts with Power Point charts and other data. And likely most people would not understand it anyway. He was probably relying the input of experts from Inmarsat and the AAIB.

      Comment


      • Originally posted by Dispatch Dog View Post
        Have we conclusively ruled out the possibility that it landed and refuelled somewhere?
        Well - so far, nothing has been ruled out "conclusively". But I think it is extremely unlikely for a 777 to show up somewhere, take on 100tons of fuel and get out again, without somebody taking notice. My questions here would be: Where is an airfield that is both big enough and not controlled within reach and can it be reached undetected? And how do you get the fuel there?

        Furthermore - and this is assuming that MH370 ended up in the South Indian Ocean - why would you refuel the aircraft and then head south?

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        • AirDisaster.com Forum Member 2004-2008

          Originally posted by orangehuggy
          the most dangerous part of a flight is not the take off or landing anymore, its when a flight crew member goes to the toilet

          Comment


          • Originally posted by Gabriel View Post
            More on the latest news:


            Aviation Herald - News, Incidents and Accidents in Aviation


            So, now it seems like fact that it crashed in the southern Indian Ocean, away from any possible landing site.

            Half (or more) of the theories have just vanished.

            I love how they develop investigative techniques after-the-fact. A lot has been discussed about how to fit planes with some technology to facilitate its location in cases like this. But almost nothing about how to find it with the technology that was available at the time of the event. A lot of creativity, teamwork and science put at work here, and knowledge has grown. Congratulations!
            You would think that military radar could read the mode C data and generate an alarm if a target stops sending mode C.

            A floating EPRB is also not a bad idea. You could probably just chuck one in the hold.

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            • I think so far (almost) all aircraft accidents have resulted in changes for the better and safety improvements. I'm certain MH370 won't be an exception.

              Comment


              • Originally posted by Peter Kesternich View Post
                Well - so far, nothing has been ruled out "conclusively". But I think it is extremely unlikely for a 777 to show up somewhere, take on 100tons of fuel and get out again, without somebody taking notice. My questions here would be: Where is an airfield that is both big enough and not controlled within reach and can it be reached undetected? And how do you get the fuel there?

                Furthermore - and this is assuming that MH370 ended up in the South Indian Ocean - why would you refuel the aircraft and then head south?
                Afaik, the MH-B772ER hasn't shown up on any place on this planet until now.

                Thus, I second your opinion, Mr Kesternich. Either a 772ER is found on an airport which was not her destination, and this airport is not smaller than my HomeAirport, because a 772ER can't be fueled at the "Wasserkuppe" afaik (German pilots know what i mean).

                Or, and this is what most of the men in the television news say, included Mr Kleber from the "ZDF heute journal": there is hope that MH-B772ER can be found, but not in a "ready for t/o" condition...

                PS: Several German News Offices reported, that MH-B772ER performed a 180 degree left turn on its way to Beijing. This would mean a heading of almost exactly 180 (South). And more than 1 man in the ZDF news office says "no professional pilot flies a B772ER into Antartica." And I second this opinion.

                Bad news for all relatives of the crew and pax of flight MH370.
                Last edited by LH-B744; 2014-03-24, 22:11. Reason: +details
                The German long haul is alive, 65 years and still kicking.
                The Gold Member in the 747 club, 50 years since the first LH 747.
                And constantly advanced, 744 and 748 /w upper and lower EICAS.
                This is Lohausen International airport speaking, echo delta delta lima.

                Comment


                • Shortly after the PM's press conference of Mar 24th 2014 Inmarsat reported that the new analysis of their satellite data used to identify the corridor and final location was based on the Doppler effects modifying radio waves and frequencies depending on speed and direction of travel of the aircraft, these data were compared to other flights. The computations are not precise enough to give the accurate position, however, made it possible to identify the general location. The new modelling and comparism were developed after the first discovery of the data on Mar 11th 2014, the work is still in progress.
                  I would be surprised if all data comes from a pure civilian satellite(s). Why would they collect Doppler data? Even if they somehow started gathering data before the flight ended, I can't really imagine this.
                  Not entirely civilian, perhaps multiple satellites on LEO, sure. While probably not exactly designed for tracking aircraft, they generally may not know what they're dealing with, and may record everything possible (e.g. effective frequencies and decoded data streams) for further analysis. Add the Inmarsat distance data and they may have a really good idea what was going on.

                  K.

                  Comment


                  • Wow any scrap of meta-information and this thread lights up! I thought we'd decided back some years that without the data recorders, no theory is safe. Also as someone helpfully pointed out, finding surface debris is a long way from finding the recorders. I know the governments are under pressure, but you'd think by now they wouldn't hazard any sort of positive dispatch, only to have to retract it. Again, 2 years to the finding of AF447's recorder. This is going to be a historic thread by that time. But, hey, there's a small number of experts here who won't sit idle in that time period. The ones who love the technical stuff will have a field day. As for the victim families, that is a group that never is happy at any point. Crashes may be the rarest thing on earth, but for each family member, it will leave its mark on them for a life time. And some families will now be anxious every second while someone they love is on a plane till they get a call of a safe landing. That's what we live with in the 21st century. We all fly, and our families all wring their hands (well,not ALL the families, but most)

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                    • Originally posted by Evan View Post
                      Until actual wreckage is recovered and identified, all they can actually conclude is that MH-370 was last positioned there. Yes, they would have run out of fuel and there was no possibility for landing in that region IF the fuel on board can be established as being true to the fuel order. A minor technicality perhaps but I think it is best to cross all your t's before making conclusive statements based on inference rather than evidence.
                      That would be hard. Someone would have noted that the fuel truck had less fuel than it should.

                      And, if nothing else, at the last ping they were 1 hour away of nowhere, and the next ping one hour later never came. That, with a high probability, means that the plane was already down within 1 hour of the last ping, which in any direction would still be nowhere.

                      --- 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 kris View Post
                        I would be surprised if all data comes from a pure civilian satellite(s). Why would they collect Doppler data? Even if they somehow started gathering data before the flight ended, I can't really imagine this.
                        This just guesswork, but I don't think they were actively collecting doppler data, but am guessing that either the signal was faintly picked up from a second satellite virtually out of range and variation of timings compared; or since it mentioned doppler, that the frequencies it was transmitting on are altered slightly depending whether it was moving towards or away from the satellite. For instance, transmitting at 2.4Ghz, but effective frequency 2.39Ghz when moving towards, 2.41Ghz when moving away. Close enough to the actual frequency that it is received and the frequency logged. Assuming the satellite is receiving a wider band then it is probably normal to record the precise frequency.

                        Comment


                        • Originally posted by Evan View Post
                          Until actual wreckage is recovered and identified, all they can actually conclude is that MH-370 was last positioned there. Yes, they would have run out of fuel and there was no possibility for landing in that region IF the fuel on board can be established as being true to the fuel order. A minor technicality perhaps but I think it is best to cross all your t's before making conclusive statements based on inference rather than evidence.
                          Hi guys been a looong time since I have posted here.
                          Just to answer the fuel question. ACARS reports typically include Fuel On Board.
                          When it left the gate the ACARS would have reported push back or OUT, then on take off ACARS would have reported OFF.
                          The is is called the OOOI reports, Out, Off, On, In. Each of these reports typically include a time and Fuel on board. Additionally the routine enroute reports will include position, time to arrival and Fuel on board. So given that the aircraft disappeared twenty do minutes after it's last routine ACARS enroute report, they would have a pretty clear idea of the remaining fuel. This is read from the fuel quantity system, thus the pilot cannot fool it.
                          So the estimation of maximum range would be determined by what flight level and engine power it was being flown at. Boeing would be running simulations and calculations to give a range estimation based on the variables.

                          Comment


                          • Originally posted by Gabriel View Post
                            That would be hard. Someone would have noted that the fuel truck had less fuel than it should.

                            And, if nothing else, at the last ping they were 1 hour away of nowhere, and the next ping one hour later never came. That, with a high probability, means that the plane was already down within 1 hour of the last ping, which in any direction would still be nowhere.
                            That would be hard. Someone ...
                            i.e. in professional pilot terms "one of the two pilots",
                            ...would've noticed that there is not enough fuel on board.

                            As my avatar shows, I don't know much about the triple7. But I know something about fuel on board a B744...

                            Your assumption makes us believe that the MH-B772ER didn't take enough fuel on board in WMKK to reach Beijing.

                            This is really hard to believe!
                            The German long haul is alive, 65 years and still kicking.
                            The Gold Member in the 747 club, 50 years since the first LH 747.
                            And constantly advanced, 744 and 748 /w upper and lower EICAS.
                            This is Lohausen International airport speaking, echo delta delta lima.

                            Comment


                            • Originally posted by sjwk View Post
                              This just guesswork, but I don't think they were actively collecting doppler data, but am guessing that either the signal was faintly picked up from a second satellite virtually out of range and variation of timings compared
                              Would require precise timestamps and multiple listening satellites. Satellites generally don't pick up random signals, unless they're designed to do precisely that.
                              or since it mentioned doppler, that the frequencies it was transmitting on are altered slightly depending whether it was moving towards or away from the satellite. For instance, transmitting at 2.4Ghz, but effective frequency 2.39Ghz when moving towards, 2.41Ghz when moving away.
                              Obvious, but
                              Close enough to the actual frequency that it is received and the frequency logged.
                              Wouldn't be close enough, nothing would be received. The receivers generally don't log the received signal frequency, and they don't have means to measure it. They either receive data, or they don't.
                              Assuming the satellite is receiving a wider band then it is probably normal to record the precise frequency.
                              The band width doesn't matter. What does matter is if the satellite is designed to receive random, unknown signals, possibly with a set of narrow band receivers, or e.g. some kind of radio analyzer-alike analog/digital converters.
                              Doesn't look like a very civilian equipment, though.

                              K.

                              Comment


                              • Originally posted by Gabriel View Post
                                That would be hard. Someone would have noted that the fuel truck had less fuel than it should.
                                Not to mention that given the fuel provider will be billing the airline, the refueller will know exactly how much fuel was pumped in. They have fuel meters on the trucks pump. This forms the basis for how much they bill the airline, and additionally forms the basis for the flight crew to confirm their fuel on board.

                                The process is like typically like this.
                                Pilot requests a total fuel figure. The refueller arrives and connects to the aircraft, he will zero his measuring equipment prior to refuelling, notate the aircraft registration, flight number and airline in the trucks measuring system.
                                Refuelling will begin and the refueller will ensure they fill to the requested amount. Then disconnect.
                                The total fuel on board is a combination on what was already on the aircraft and how much was pumped in. typically the fuel pumped in by the truck is measured in litres (I am sure Malaysia uses metric). The refueller will them using the trucks computer to create a fuel docket which will have the aircraft rego, flit number, location, time. Airline etc and Fuel supplied. This docket is handed to the flight crew. Obviously the Fuel company have a record also.
                                The flight crew then must perform a calculation to confirm their indicated fuel matches their calculated fuel based on fuel before refilling plus fuel added.
                                The Litres figure is converted using a simple formula based on fuel density, which is a function of the temperature of the fuel being pumped in. The warmer the fuel the lower the density. But the nominal figure is 0.8. So 50,000 litres x 0.8 would be 40,000kg. If the aircraft had 5,000 kg on board before refuelling then the fuel onboard should indicate 45,000 kg. The indicated fuel quantity is checked against the calculated fuel and should be with in 3%.

                                So in short unless the refueller was complicit in a conspiracy and secretly added fuel. The know exactly how much fuel was added and what the total fuel requested was before the aircraft left. Even if the refueller did so, they trucks usually have two fuel meters, a total fuel pumped by the truck like your odometer in your car, which does not get reset and the meter used to refuel the aircraft which is reset each time.

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