Slashdot Mirror


Malaysia Airlines Flight 370: Experts Unable To Replicate Inmarsat Analysis

McGruber (1417641) writes "The lynchpin of the investigation of the disappearance of Malaysia Airlines Flight 370 has been the pings from the plane to one of Inmarsat's satellites. The pings are the sole evidence of what happened to the plane after it slipped out of radar contact. Without them, investigators knew only that the plane had enough fuel to travel anywhere within 3,300 miles of the last radar contact—a seventh of the entire globe. Inmarsat concluded that the flight ended in the southern Indian Ocean, and its analysis has become the canonical text of the Flight 370 search. It's the bit of data from which all other judgments flow—from the conclusive announcement by Malaysia's prime minister that the plane has been lost with no survivors, to the black-box search area, to the high confidence in the acoustic signals, to the dismissal by Australian authorities of a survey company's new claim to have detected plane wreckage. But scientists and engineers outside of the investigation have been working to verify Inmarsat's analysis and many say that it just doesn't hold up."

21 of 245 comments (clear)

  1. Re:An what? by wooferhound · · Score: 5, Funny

    These are not the Satellite signals that you are looking for . . .

    --
    We are Dead Stars looking back Up at the Sky
  2. Re:An what? by ClickOnThis · · Score: 4, Insightful

    "Analysis" would be my guess.

    --
    If it weren't for deadlines, nothing would be late.
  3. The explanation is simple by Anonymous Coward · · Score: 5, Funny

    The aircraft did not crash; it was hijacked by the US Government, and flown to Diego Garcia under remote control after all the passengers were killed by asphyxiation at 45,000 feet. After landing the plane was refuelled, its logos painted over/covered up, and its valuable cargo (next generation radios with SDR technology) removed. It then took off again and flew on to its final destination--probably Kandahar, Afghanistan--where it will be outfitted with a large bomb (read: nuke). It will then be flown into an American city to cause a 'false flag' attack which will be blamed on Iran, North Korea, etc, as a casus belli for World War 3.

    I would tell you more but som....hang on, there's a knock at the door.

    1. Re:The explanation is simple by ColdWetDog · · Score: 5, Funny

      Yeah, that knock on your door is your mother.

      Time for your meds.

      --
      Faster! Faster! Faster would be better!
    2. Re:The explanation is simple by lgw · · Score: 4, Informative

      But that's the point, of course. Blacksmiths don't (usually) melt the metals they work with, just soften them a bit. And the construction of the various WTC buildings of course depended on the rigidity of the steel they were built with (in different ways in the different buildings).

      Did you know there's a technical term for materials that, rather than melting with an abrupt state change, go through a long transition becoming gradually more plastic and malleable? We call those "metals".

      --
      Socialism: a lie told by totalitarians and believed by fools.
    3. Re:The explanation is simple by antdude · · Score: 4, Funny

      Also, don't forget to tell her "Happy Mother's Day!" ;)

      --
      Ant(Dude) @ Quality Foraged Links (AQFL.net) & The Ant Farm (antfarm.ma.cx / antfarm.home.dhs.org).
    4. Re:The explanation is simple by wish+bot · · Score: 4, Informative

      Just replying so that anyone else reading this isn't suckered in by your mistakes or ignorance:

      1. Steel gets 'soft' enough between 500 and 700 DeC to lose most of its structural properties.
      2. A typical fire - like something that could start in an office - can easily get to 700+ DegC. This includes the gas coming off the fire.
      3. A bit of jet fuel could easily set most things inside an office building alight.

      Source - I design buildings not to fall over in a fire.

      --
      lemonade was a popular drink and it still is
  4. Why is this a surprise? by Anonymous Coward · · Score: 4, Insightful

    If Inmarsat haven't released all of the data used in the analysis, why is anyone surprised that they can't recreate it?

  5. Not so.... by Anonymous Coward · · Score: 5, Interesting

    Not so. These critics may or may not be correct when they raise several issues, including the plane seeming to be moving at a good clip before it was taking off. But on the most critical of factors, they're totally wrong:

    "Recall that the Marco-Polo math alone doesn’t allow you to tell which direction pings are coming from. So how could Inmarsat claim to distinguish between a northern and southern path at all? The reason is that the satellite itself wasn’t stationary."

    No, the slow drift of the satellite wasn't a factor. I've yet to hear Immarsat formal statement of their rationale, but their graph shows quite clearly what it was. Their reasoning hinges on the fact that the plane began its deviant flight above the latitude of the satellite. That is quite important.
    If the plane flies northward along a relatively fixed course, the doppler shift will aways show it moving away (down doppler). However, it the plane flies southward on a steady course, there'll be a short time (one ping it turns out) when it is approaching the latitude of the satellite and thus giving a more up (or less down) doppler. That's what you see in the Immarsat chart. Once the aircraft has crossed the satellite's latitude, then its southward path will have it traveling away from the satellite just like the northern route. It's that notch DOWN at between 18:30 and 19:30 followed by a rise upward that says southbound.
    That said the critics do raise some relevant issues and they do point out the Immarsat needs to release a detailed report with all their reasoning, so it can be more intelligently critiqued.

    1. Re:Not so.... by Anonymous Coward · · Score: 5, Informative

      The problem with this analysis is that the Doppler "spike" would not have come from a due South trajectory. It is most likely to have come from a change of trajectory almost directly towards teh satellite. The implication is that this was a "ping" that just happened to have occurred during a turning manouevre; given that the SATCOM terminal on the aircraft uses a high-gain steerable antenna, it is not surprising that an "unscheduled" ping took place during a turn, as the beam-steering unit reacquired the satellite.

      The other massive confounder with this analysis is that the SATCOM terminal necessarily pre-compensates its transmissions for Doppler shift. The channel bandwidth in the Inmarsat Classic Aero system is sufficiently narrow that when received at the Satellite, the center frequency must be +/-250 Hz of nominal. As Doppler shift due to the expect motion of an aircraft is in the region of +/- 800 Hz, this can only be done by active pre-compensation.

      You'll notice from the Inmarsat Data that the uncorrected Doppler shift is within 250 Hz of expected, indicating that some pre-compensation is present.

      Without details of how the compensation works, analysis is very difficult, if not impossible. A scan of the patent literature suggests that both measured-Doppler compensation (i.e. the aircraft terminal measures Doppler shift on a satellite broadcast channel, and applies an equivalent compensation on its transmissions) and estimated Doppler compensation (i.e. the satellite terminal communicates with the aircraft's navigation reference unit to obtain heading, and velocity information, and then computes an expected Doppler shift which is applied to transmissions) may be in use.

    2. Re:Not so.... by Anonymous Coward · · Score: 4, Interesting

      Couple of possibilities:

      1) They did and they are not saying. Seems unlikely as the fact that Jindalee can, for example, track commercial airliners all the way from Singapore, is pretty much common knowledge.
      2) They didn't track it because they couldn't. Sadly, despite the money spent on it, Jindalee is great when it works, but unfortunately it doesn't work all the time. This partly explains why Australia has had to buy expensive AWACS aircraft as well as spending big money on Jindalee.

  6. Re:Who? by ColdWetDog · · Score: 4, Insightful

    TF Author is basically collating some information available on the web (we do that these days, you know). The original data that is attempting to refute INMARSAT's analysis is from two people (with blogs) which do have some expertise in the field:

    So it should be straightforward to make sure that the math is right. That’s just what a group of analysts outside the investigation has been attempting to verify. The major players have been Michael Exner, founder of the American Mobile Satellite Corporation; Duncan Steel, a physicist and visiting scientist at NASA’s Ames Research Center; and satellite technology consultant Tim Farrar. They’ve used flight and navigation software like STK, which allows you to chart and make precise calculations about flight scenarios like this one. On their blogs and in an ongoing email chain, they’ve been trying to piece together the clues about Flight 370 and make sense of Inmarsat’s analysis. What follows is an attempt to explain and assess their conclusions.

    Yes, this is an appeal to authority, but this is also a popular, non scientific, non peer reviewed bit of journalism. I'm not expecting much more.

    --
    Faster! Faster! Faster would be better!
  7. What were the pings then? by SuperKendall · · Score: 4, Interesting

    I think it's pretty interesting that a number of devices detected pings, but there is apparently (as per the article) nothing was found in the area where they heard the pings.

    So what did they hear? How can you get a false positive on a listening device looking for a specific frequency?

    I wonder if instead of just sending out pings, a black box when hitting water should send out a burst of broad spectrum very high powered radio waves that satellites around the globe could detect...

    --
    "There is more worth loving than we have strength to love." - Brian Jay Stanley
  8. Re:I DON'T CARE! by ColdWetDog · · Score: 5, Insightful

    It's really not about the people on the plane. It never has been past the first few hours.

    It's about a world wide industry that doesn't like expensive bits of it fall out of the sky for no reason. It's also not about the money. Hell, we could shut down an aircraft carrier battle group and feed the entire planet for a decade - don't look to humans to be rationale about that issue and don't try to conflate them.

    --
    Faster! Faster! Faster would be better!
  9. Re:Strange, indeed by jythie · · Score: 5, Insightful

    One thing to note, Georesoance did NOT find a plane. Further investigation into the company (though skipped over by the media outlets that got suckered by them) showed them to be just another shell company run by people with a long history of pseudoscience scams. They buy up defunct exploration companies in order to reuse the name, bilk some small investors that are eager to buy into the idea that a small pluky company has magic technology that 'the establishment' does not believe in.. usually ending up much poorer for the experience.

    So basicly the media got fooled by some high tech psychics who normally would have been dismissed completely but somehow got just enough attention to be taken seriously.

  10. Re:I DON'T CARE! by jimicus · · Score: 4, Insightful

    Yes, you're partially right on that but in my opinion there are enough other incidents that can yield data - missing one is really not that major.

    Not regarding the Boeing 777 there haven't. There's only been seven accidents, and only one prior to MH370 that involved any fatalities. And if the cause was a fault with the plane rather than human error/intervention, it's important to know because there's a whole bunch of other, more-or-less identical aircraft in use and it's entirely possible that one or more of them has the same problem.

  11. Re:I DON'T CARE! by fuzzyfuzzyfungus · · Score: 5, Insightful

    In general, people seem to have a strong distaste, often backed by substantial investigative resources, for mysterious mysteries cropping up in the course what what is supposed to be a routine and mature process.

    Commercial aviation (at least the large-aircraft stuff, stats for dinky little aircraft are less reassuring) is ordinarily so well hammered out that basically every air crash has a strong element of mystery to it and so the investigators come and try to figure out what went wrong.

    Compare to cars, which kill plenty more people (and, unlike malnutrition and ghastly tropical parasites) people we usually care about; but still get minimal investigative attention because so many of the accidents are either 'operator was piss-drunk and/or exhausted', 'operator was flagrantly disregarding the rules for that area of the road', or 'vehicle maintenance was somewhere between horrendous and nonexistent'.

  12. Re:Simpler: Electrical Fire by FatLittleMonkey · · Score: 4, Interesting

    The rest of the explanation is that the crew were overcome by smoke/fumes. (They're supposed to have independent (bottled) oxygen supply, but it's happened before.) The aircraft flew on autopilot on the last entered heading until it ran out of fuel. (Which has also happened before.)

    Why didn't they call a mayday earlier? The rule of thumb for pilots is: Aviation/Navigation/Communication. First you get control of the aircraft, understand what is happening. Then you work out your position/course and heading (actual and intended). Then, and only then, do you worry about telling anyone about it. If they were caught between "Navigation" and "Communication", that would explain their actions and their silence.

    You are probably scoffing and going "Bah, what are the odds of that!" But your alternative scenarios are "Plane was hijacked by... conspiracy... secret landing... passengers killed/being held.... etc..."

    So the contrast is, "Thing which has happened to aircraft several times before", versus "Bizarre conspiracy by shadowy forces". I prefer the odds of the former until there's actual evidence of the latter.

    --
    Science is all about firing a drunk pig out of a cannon just to see what happens.
  13. Re:I DON'T CARE! by camperdave · · Score: 4, Insightful

    Wrong! The world produces more than enough food, and agricultural output grows four times for every three times the population grows. World hunger is a distribution problem, not a production problem. In fact, fully a third of the food produced in the world is wasted.

    --
    When our name is on the back of your car, we're behind you all the way!
  14. Re:Spy games by Richard_at_work · · Score: 4, Informative

    The why not is an easy one - spy satellites are put into orbits which cover the likely hotspots for their use, and changing those orbits lessens the useful life of the satellite fairly significantly.

    Oh, and no one really wants to give away the true capabilities of their spy satellites...

  15. play Jenga to find out, or turn on your stove by raymorris · · Score: 4, Informative

    More specifically, it collapsed as though the FIRST floor could no longer support the weight of the entire building on top of it. You can see that in the videos.

    You can see the exact same thing in your kitchen if you have a gas stove. I know it's more fun to read spy stories than to actually try an experiment, but just know that I'm going to ignore any replies from you until you try the experiment yourself.

    Go get a few wire coat hangers or similar metal wire, and some pans. In your kitchen, set up some wire supports to hold a pan four inches above the flame. Try to make the supports symmetrical, like the way a professional building would be designed. Pretend that the wire costs a million dollars per inch, so you'll use the minimum amount of wire necessary to hold the pan up. A bundt cake pan or something with a central opening would be the best simulation, simulating the center elevator columns.

    Also keep in mind WTC 7 was tricky to design because the first couple of floors were built around / over an existing power station, so it was designed to use fewer, stronger supports than most buildings would. (You can't put a 40' wide support column right through a part of the power station).

    Once the first pan is in place, add three more "floors" (pans), so you have four or more floors, each a few inches apart.

    Now tturn the fire on high and wait 5-15 minutes. What Wil happen is that the heat will soften the metal supports just a bit at first, then more so as they heat up. At some point (as high as 500-600 degrees), they'll get soft enough that they collapse under the weight of all those pans. The stack will drop, just like WTC 7.

    I KNOW yyou want to argue with me right now. That's cool, you can do that. But first, go in your kitchen and give it a try. Then you can argue from actual knowledge as opposed to repeating silly ghost stories about topics you're unfamiliar with.