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Robotics Transportation

Robots Dive Deep To Solve Airliner Crash Mystery 156

Posted by timothy from the pre-trial-discovery-for-serious dept.
coondoggie writes "A small squadron of undersea robots has begun to conduct a 4-month, 3,900 square mile search of Atlantic Ocean bottom looking for the deep-sea wreck site of and black boxes from Air France Flight 447 which crashed off the coast of Brazil nearly two years ago. The Air France plane was flying from Rio de Janeiro to Paris, when for exact reasons that remain a mystery, it crashed into the Atlantic Ocean on June 1, 2009, taking with it 228 souls."
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Robots Dive Deep To Solve Airliner Crash Mystery More

Robots Dive Deep To Solve Airliner Crash Mystery

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  • Reasons unknown?? (Score:5, Informative)

    by Ark42 ( 522144 ) <slashdotNO@SPAMmorpheussoftware.net> on Thursday March 31, 2011 @09:24PM (#35684712) Homepage

    Isn't this the flight that flew right into a huge huge storm that was obscured on their radar by a smaller storm which was safe enough to fly through. As soon as the larger storm was in view, it was too late to change course and fly around it. I heard the most likely case is extreme icing of the sensors that monitor airflow, causing autopilot to disengage as the plane no longer knew its own speed. Without any way to know the current speed, the plane lost altitude and crashed, due to a small window of safe speeds that don't result in altitude loss.

    • Re:Reasons unknown?? (Score:5, Interesting)

      by bradgoodman ( 964302 ) on Thursday March 31, 2011 @09:31PM (#35684754) Homepage
      I heard of this same sort of thing happening once to a plane. What happened was that the plane was just painted. During the painted process, they put masking tape over the Pitots (holes/ports used to measure air pressure). They forgot to take the tape off, and when they were in flight, the airspeed, altitude, and stall warnings all went crazy from the erronious pressure readings on the clogged/covered pitot tubes. Result was bizarre instrumentation - overspeed and stall warnings at the same time, etc. They wound up crashing from confusion. Perhaps icing in the pitot tubes were causing a similar thing here.

      • Re:Reasons unknown?? (Score:4, Informative)

        by jamesrt ( 684945 ) on Thursday March 31, 2011 @10:35PM (#35685104)

        I heard of this same sort of thing happening once to a plane. What happened was that the plane was just painted.

        The plane crash being referred to is this one: http://en.wikipedia.org/wiki/XL_Airways_Germany_Flight_888T [wikipedia.org]

        • Re: (Score:2)

          by tg123 ( 1409503 )

          I heard of this same sort of thing happening once to a plane. What happened was that the plane was just painted. During the painted process, they put masking tape over the Pitots (holes/ports used to measure air pressure). They forgot to take the tape off, and when they were in flight, the airspeed, altitude, and stall warnings all went crazy from the erronious pressure readings on the clogged/covered pitot tubes. Result was bizarre instrumentation - overspeed and stall warnings at the same time, etc. They wound up crashing from confusion. Perhaps icing in the pitot tubes were causing a similar thing here.

          The plane crash being referred to is this one: http://en.wikipedia.org/wiki/XL_Airways_Germany_Flight_888T [wikipedia.org]

          Ummm I think it might be this one http://ehttp://en.wikipedia.org/wiki/Aeroperú_Flight_603 [wikipedia.org] But the plane was being cleaned , not painted and also it was a Boeing plane not an Airbus.

          • Re: (Score:1)

            by jamesrt ( 684945 )

            I heard of this same sort of thing happening once to a plane. What happened was that the plane was just painted.

            The plane crash being referred to is this one: http://en.wikipedia.org/wiki/XL_Airways_Germany_Flight_888T [wikipedia.org]

            Ummm I think it might be this one http://ehttp://en.wikipedia.org/wiki/Aeroperú_Flight_603 [wikipedia.org] But the plane was being cleaned , not painted and also it was a Boeing plane not an Airbus.

            Maybe; however, the one I referenced was an Air NewZealand owned plane, and it was in the news at lot over here in NZ when it happened.... Point is that I agree with the original poster about flight instrumentation information loss causing control issues.

      • Yep, screwing with the air data ports can cause some nasty accidents. Take a look at http://en.wikipedia.org/wiki/Northrop_Grumman_B-2_Spirit#Accident [wikipedia.org] for a $1.4 billion (that's 'B') crash caused by water in the air data ports.

    • Not necessarily. Even without accurate airspeed readings, the pilots should have still been able to maintain safe airspeed by setting the engines to a specific power output and trimming to a specific angle of attack. Probably pilot error (i.e. being distracted with alarms and not remembering to adjust throttle and angle....) but without that box it's hard to really know.
      • In fact, this happens more often than you know and is a very typical response to a situation like this. Bottom line: loss of airspeed data should in no way shape or form be a catastrophic event.
        • No, but incorrect airspeed data might.
          • Incorrect airspeed is one thing. However we know from the telemetry the plane sent as it was going down that the pitot tubes were giving conflicting information, which I would assume would lead the pilots to disregard all pitot information from that point forward and take the appropriate steps. I'm pretty sure that is SOP for any fly-by-wire aircraft (or any aircraft for that matter...). Any pilots want to chime in?

            • A lot of what you said is essentially correct. I just happened to watch a Nova episode on this flight. Here are a few things that Nova brought up:

              • The flight probably encountered turbulence. The SOP for that is to reduce airspeed.
              • On the Airbus 330 and many fly by wire commercial airliners, the way to do this is to adjust a speed setting and not the throttle. This allows the computer to make adjustments.
              • However if the pitot tubes failed, the first response of the computer would be to turn off all assist

        • The bottom line doesn't know people. A malfunctioning landing gear light bulb can 'cause' a crash. The word is "situational awareness".. Lose that, and your landing will probably do more than just loosen a few teeth.

        • In fact, this happens more often than you know and is a very typical response to a situation like this. Bottom line: loss of airspeed data should in no way shape or form be a catastrophic event.

          There was that aircraft in the US which stalled in conditions with ice formation and the pilot pulled up rather than performing a stall recovery. Maybe pilots these days spent too much time programming the autopilot and not enough doing stick and rudder flying.

          • Unfortunately, not all pilots are of the same quality. Pilots from smaller airlines tend not to have the same experience as from the larger ones. The larger airlines are more selective and have higher standards since they are more risk adverse. They also pay more for them though.

      • Re: (Score:3)

        by 517714 ( 762276 )
        Pilot error, yes, but the throttles do not indicate their settings on an Airbus except when manually set. The handles can say 90%, but if they will be at the last setting that the autopilot used when it disengaged. This is a counterintuitive design that does not properly consider human interface. Standard procedure for loss of airspeed indicators is to set the control surfaces, angle of attack and throttle to values that will keep the aircraft flying safely. One theory is that the crew made the mistake
        • Good point, keeps coming up in expert forums. What exactly is the claimed advantage of a throttle like this? Sure, you can 'get used to it', but does anyone know?

      • Re:Reasons unknown?? (Score:5, Interesting)

        by martyb ( 196687 ) on Thursday March 31, 2011 @10:25PM (#35685052)

        Not necessarily. Even without accurate airspeed readings, the pilots should have still been able to maintain safe airspeed by setting the engines to a specific power output and trimming to a specific angle of attack. Probably pilot error (i.e. being distracted with alarms and not remembering to adjust throttle and angle....) but without that box it's hard to really know.

        Honest Question: Why in this day and age do we still have to chase down a black box? More and more airliners now provide in-flight internet connections. Couldn't they just transmit it as well as record it to the black box? TFA says this search is costing them $12.5 million. That would pay for a lot of upgrades and support for this.

        Continuous Transmission? Send all of the recorded data to both the black box and some remote data center, too. If this is too much to transmit continuously, then maybe a subset of the data? I know planes are becoming increasingly complex and automated, so there's probably loads more data that *could* be considered for transmission. Still, something is better than nothing (what we have now.) Pick some subset of the available data and send it periodically.

        Burst Transmission? Instead of a continuous stream of data, when the pilot (or plane) detects a "dangerous condition", it starts sending a high-speed burst of accumulated data, and continuously until things look "normal" again. Say the plane takes a sudden 200-foot drop in altitude. Or banks unusually sharply. Or... whatever. Just ignore the values that appear 99.9% of the time, and only trigger outside that normal range. (numbers pulled out of thin air; pick whatever works best.)

        At this point, there's nothing much to go on. Imagine if we had the last few minutes' airspeed, altitude, as well as settings for the flaps, rudder, and engine would be an enormous improvement over what we've got now. I suspect the pilots' unions might raise a concern about monitoring and potential for it to be help against them, but I could also imagine some kind of escrow mechanism where the data is sent and stored, but only to be accessed upon certain, predefined circumstances.

        Admittedly, this is quite rough. I'd like to think that there is at least some part of this which could be implemented in parallel to the provision of internet access on planes. I'd appreciate it if anyone who knows more about these things could comment on the viability of this and/or the technical limitations/challenges which I'm missing here.

        • Re: (Score:1)

          by khallow ( 566160 )

          Couldn't they just transmit it as well as record it to the black box?

          No. For example, if some aspect of an accident knocks out the transmitter or if nobody receives the data at a critical time. Usually, putting it in a black box in the plane works really well since it is hard to lose a plane. Possible, as in this case, but usually you can find the smoking crater where the plane crashed.

        • Re:Reasons unknown?? (Score:4, Informative)

          by Slutticus ( 1237534 ) on Thursday March 31, 2011 @10:54PM (#35685214)
          Actually, the plane transmitted quite a lot of information to AirBus HQ as it was going down, but that system (ACARS) is quite outdated i think. The last three minutes of the transmissions gave a wealth of data related to alarms and faults that were occurring (i.e. inconsistent airspeed readings, excessive vertical speed, autopilot information, etc...). It would be interesting to see how much voice data could be reliably transmitted in a situation like that.

        • Re: (Score:2, Informative)

          by Anonymous Coward

          http://spectrum.ieee.org/aerospace/aviation/beyond-the-black-box [ieee.org]

          Yes this is being talked about

        • You forget that all electromagnetic radiation cause airplanes to fall out of the sky. That's why it's so important to shut down your Kindle back in row 79.

          It's a wonder that airplanes survive in sunlight, at all.

        • > Burst Transmission? Instead of a continuous stream of
          > data, when the pilot

          According to the NOVA (PBS) episode on this subject (which did an excellent job of determining the probable chain of events and solving the mystery though not "exact"ly, if that's a synonym for definitive, for that you need the witness of absent the CVR and FDR) the flight went catastrophic within ~94(?) seconds. Hence your burst implies a window of opportunity. Ultimately this is a matter of resources, or the lack thereof. R

        • I'd appreciate it if anyone who knows more about these things could comment on the viability of this and/or the technical limitations/challenges which I'm missing here.

          I work on air traffic control software and ideas like this are being looked at. Aircraft transmit engineering data (among other things) through ACARS satellite links. Messages from this system provided a lot of information to the investigation. Cheaper data links have only recently become available. The turn around time for system design in aviation is very long. Designs are very detailed and rigorous. Integration issues on the aircraft would lengthen the time taken to implement a system such as you describ

        • Re: (Score:2)

          by tlhIngan ( 30335 )

          Honest Question: Why in this day and age do we still have to chase down a black box? More and more airliners now provide in-flight internet connections. Couldn't they just transmit it as well as record it to the black box? TFA says this search is costing them $12.5 million. That would pay for a lot of upgrades and support for this.

          Politics, really.

          In an ideal world, we'd have all the planes beaming back CVR and FDR data (the black boxes) to ground stations and satellites, as well as the units themselves (sh

    • Yes. The PBS show NOVA ran a documentary on the crash last month (you can watch the whole thing online here [pbs.org]) that came to the conclusion you describe. (Though it should be emphasized that it's all speculation until more evidence is gathered.)

    • Re: (Score:2)

      by Sir_Sri ( 199544 )

      Theories as to what caused the crash are not the same as having the blackbox data and being able to confirm any given theory, or decide that you cannot confirm any theory given the state of the blackbox.

      Don't get me wrong. We know enough about aircraft, and the environment factors to make decent educated guesses. But if it flew into a storm it *should* have been able to handle and failed, that's very different than flying into a storm it shouldn't have been able to handle.

    • Re: (Score:2)

      by tibit ( 1762298 )

      Without any way to know the current speed, the plane lost altitude and crashed

      As far as I know, on that particular type you can continue level flight safely without airspeed data. There are tables and you pretty much look up the throttle setting given air density, the latter can be approximated from GPS/INS in case your static system is dead, too. You just need to be aware that the Pitots have iced over. If you are unaware, shit goes wrong, and my bet is that it's a human factor at play, just like with China Airlines 006 where the underlying wetware problem was similar: a disconnect

    • Re: (Score:2)

      by Myopic ( 18616 )

      Yes. Nova did a documentary about it: "Crash of Flight 447". It's pretty good and covers the science reasonably well.

    • There was an episode on Nova that posited exactly this. Ultimately, pitot tubes iced over and the plane was unable to determine airspeed so kicked out of autopilot, and the human pilots were too slow to respond with the suggested throttle and pitch settings in such a case.

      What amazes me is the incredibly thin window they (speedwise) they have to fly in to be safe. +/- 10kts or something like that.

    • You are probably right, although it is interesting to make note of a crash of a Spanish airliner which occurred around that timeframe and turned out to be caused by malware aboard their avionics system. Now that's scary????

  • I knew Kia's were small cars, but I had no idea you could fit so many on a plane.

  • pitot probe failure most likely cause. (Score:3, Informative)

    by bongey ( 974911 ) on Thursday March 31, 2011 @10:47PM (#35685158)
    I write flight diagnostic software , special software the tries to determine the root cause after number of BIT/and OR ACARS messages. I was especially interested in this flight. Thank god the air bus aircraft sent the ACARS messages otherwise we would have no idea what happened to it. Nova video is pretty convincing. Especially when in the flight simulator , and they cause a simulated air speed failure. The exact same ACARS messages are produced by the simulator that were produced by flight 447. http://www.pbs.org/wgbh/nova/space/crash-flight-447.html [pbs.org] . NOVA concluded bad weather caused the failure of the air speed sensors (pito tubes). Air speed sensor failure cause the auto pilot to fail, which turned the cockpit into a christmas tree of error and warning lights. Finally, pilot error in which they didn't react quickly enough .The pilots had to react quickly enough and apply just the right amount thrust and pitch to avoid a dramatic stall. The plane final injuries were consistent with dramatic stall, literally falling strait down out of the sky.

    • Re:pitot probe failure most likely cause. (Score:4, Interesting)

      by by (1706743) ( 1706744 ) on Thursday March 31, 2011 @10:58PM (#35685232)
      First thing I did when I opened this thread was Ctrl-F for "nova". I know nothing about the aeronautics, but I too found this to be a very convincing explanation.

      What really struck me as odd was that (as I recall from the Nova video) planes are out of communication from land when in the middle of the ocean. With humanity's level of satellite technology (not to mention radio-wave-bouncing-off-of-atmosphere-skillz), this just seems weird.
      • Especially odd when most trans-oceanic flights offer calls(albeit at $10/minute) through seatback phones. It might well be, though, that the sort of conditions that cause aircraft to crash don't do much for reception...

        • Especially odd when most trans-oceanic flights offer calls(albeit at $10/minute) through seatback phones. It might well be, though, that the sort of conditions that cause aircraft to crash don't do much for reception...

          Aircraft can send CPDLC messages though the ACARS link but they would usually only do this when they need to communicate with ATC. ACARS is expensive so crews are encouraged not to just use CPDLC to send messages which are not necessary. Once they had an emergency they would have focused on the flying and only communicated if it was going to help them in an immediate sense. We know the satellite links were working because ACARS was working.

    • What is it about modern airliners that makes them so fragile? Increase power, point nose up. These crashes make modern airliners seem like 1920s aircraft designs, before data was analyzed regarding what was safe and what was not.

      • Re: (Score:1)

        by bongey ( 974911 )
        The had some weird designs in the cockpit that makes it so you can easily not to apply throttle correctly. I guess it is designed so you can't just bump the throttle, and end up like this plane http://www.airliners.net/photo/1293784/L/ [airliners.net] , but it is weird it is newer plane.
      • My understanding is that at those altitudes, the flight envelope becomes very thin (is that the right terminology?). So too much thrust leads to too much speed leads to structural problems, and too little speed leads to a stall.

        If the planes flew at 1920 aircraft altitudes, then there would be a lot of wiggle room...however, fuel economy would suffer a lot.

        • Re: (Score:1)

          by bongey ( 974911 )
          Slow speeds can introduce stalls too, not enough air going over the control surfaces . The lack of air flow over the control surfaces, and lose of lift leads to "mushy" controls. Flaps help but they don't remove the control issue, that is why landing a plane is the hardest part.

          • I'm sorry, but you're mistaken. Taking off is the hardest part.

            Landing is (relatively) easy, with exception to extreme cross-wind scenarios. While it would not be easy, I would guess that probably around 75% of us here could be talked down by an experienced pilot (requires some smarts and situational awareness).

            Taking off, however, is chalk full of a plethora of variables, from wind direction and speed, any gusting, thrust, runway length, weight of the aircraft, balance of any cargo/passengers...the list

      • What is it about modern airliners that makes them so fragile?

        ORLY? Have you done any flying over the south atlantic lately? I have been there in a ship and for me it was like the inside of a washing machine from the perspective of a bacterium.

      • Comment removed based on user account deletion
    • And if flight 447 would have had an experienced pilot like Chesley "Sully" Sullenberger on board, they probably would have made it.

      • And if flight 447 would have had an experienced pilot like Chesley "Sully" Sullenberger on board, they probably would have made it.

        Sullenberger is a stick and rudder man. Flies gliders and light aircraft. Modern pilots are data entry operators.

    • Re: (Score:3, Interesting)

      by Anonymous Coward

      I managed to get one of our more experienced pilots to follow the rabbit down the wrong hole in a similar way in the sim yesterday. It was easy, too. I gave the local pitot and static sources a bad pressure, and then faulted the B bus to kill off the good sensor. The pilot assumed that he was getting good data from the remaining sensors and failed to notice bank angle creeping as the AP pitched down to maintain speed in climb mode. What's 3 degrees of pitch when you've got cascading faults? Every few second

      • Re: (Score:1)

        by Anonymous Coward

        oops ... pitch creeping up, not bank. "Bus" refers to the Airbus.

    • Re: (Score:1)

      by fatmal ( 920123 )
      When I was learning to fly, the instructor would quite regularly cover the flight instruments, and I'd have to fly circuits without knowing how fast I was going, or how high I was. While it is easy to estimate speed & climb from your attitude (nose above the horizon & lots of throttle usually means you're going up, nose above the horizon and no throttle you're slowing down, and will soon stall and descend (quickly too!)), I would hate to have to do that without outside visual references like the pil

      • How does the artificial horizon stay calibrated during cruise? Your real attitude changes as you follow the curvature of the Earth, so you must use the real horizon from time to time to recalibrate the gyros. Same as with a DG.

    • Comment removed based on user account deletion
      • Analysis of what debris they did found indicates the airplane was intact when it hit the water horizontally. However they didn't find the debris until 5 days after the plane was lost. The debris could have drifted quite a distance away from where the plane went down.
  • The search for this black box has been dragging on and on. I remember a few months back when it seemed that the French government was going to give up the search, given that it's cost quite a bit of money already. Other than humanist pride (which is worth more than we might say prima facie), I can't think of a goal that will be reached by furthering this search that's commensurate with the cost.
    Were there some (sons or daughters or grand-nieces) of some well-connected people on that flight? (A quick searc
    • You really don't know why they're searching again??? Search for "air france 447 lawsuit".

    • Were there some (sons or daughters or grand-nieces) of some well-connected people on that flight?

      I like that your first assumption is that the search is being pushed by rich and "well-connected people" and has nothing to do with the fact that there are many hundreds of other aircraft flying that could suffer from similar potential faults. As another responder pointed out, the French lawsuit also have significant pull (which is protocol AFAIK in France whenever loss of life occurs).

      This is less about pride a

  • Nova Documentary on Flight 447 (Score:4, Interesting)

    by catchblue22 ( 1004569 ) on Friday April 01, 2011 @01:48AM (#35685932) Homepage

    This is an excellent Nova documentary [pbs.org] on the disappearance of Flight 447. It is interesting how investigators were able to give a reasonable hypothesis as to what happened, even without the black boxes. The long and the short of it is that they think super-cooled liquid water from a serious thunderstorm overcame the pitot anti-icing heating systems, freezing over all of the pitots and thus depriving the computer of airspeed data. The computer probably panicked, suddenly switching off the autopilot (they did get data from the computer, as its satellite uplink gave some telemetry). Pilots are capable of flying without airspeed readings, but only if they react quickly. They think that prior to flying into a severe thunderstorm, the computer automatically reduced thrust, in order to slow down in anticipation of turbulence. The problem is that the only pilot feedback that the thrust was reduced would have been a tiny circle on a computer monitor...there is no physical feedback in the throttle levers in Airbus planes. The computer then probably switched off the autopilot, overwhelming the pilots with a sequence of warnings. The thrust likely remained at 70% and the pilots probably didn't realize it. After a minute so the airplane may have lost so much airspeed from the low thrust that it became unflyable, in effect causing the crash.

    Give this Nova episode a try...it is very detailed, going into many technical aspects of airplane design.

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