Air France 447: How scientists found a needle in a haystack

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35 Responses to “Air France 447: How scientists found a needle in a haystack”

  1. Anonymous says:

    They make those where I work. It’s kind of weird seeing one on the bottom of the ocean carrying data that can help explain how a plane full of people lost their lives.

  2. Anonymous says:

    People are working on the problem of remote flight data transmission, here’s a very in depth paper by The International Working Group on Flight Data Recovery: http://www.bea.aero/en/enquetes/flight.af.447/triggered.transmission.of.flight.data.pdf

    Very long, very in depth but the summary is good enough to get the gist of it.

  3. Anonymous says:

    More than a needle in a haystack. A needle in a very big hay loft.

  4. Anonymous says:

    I think I’ve figured it out. Video of the cockpit is all but irrelevant. Video of the entire outside skin of the plane could be doable for recorders, with some value.

    As for streaming data, surely you could define a range for ‘normal’ — only recorded. Then a range for ‘abnormal’ — streamed, but 95% of the time only for a few minutes.

    Finally, if ‘abnormal’ is followed by ‘nonexistent’, you have all the (relevant) data. The unexplored skill of the information age is intelligent filtering.

    The only problem is making sure that executives know the real value of transient abnormal. Not usually relevant but occasionally instructive, and especially in accident situations.

  5. MooseDesign says:

    It still boggles my mind… I’d be curious to know a little more about the modeling study that he alluded to and how its conclusions for a search area were arrived at… Hopefully the FDR and CVR, both of which appeared to be in decent condition, will reveal quite a bit more information on the circumstances that brought her down.

  6. Anonymous says:

    How about an image of Remus?

  7. dculberson says:

    Thanks for this Maggie; fascinating stuff. It’s hard to imagine seeing that image and thinking “there’s the airplane!” They must be very patient and very good.

  8. Wally Ballou says:

    Can someone knowledgable explain why air safety investigators have to rely on a hardware black box?

    Why can’t this data be streamed?

    Compare with the telemetry readings available to the Columbia investigation team, which practically pointed a flashing neon sign at the cause of the breakup.

    • Michael Smith says:

      Why can’t this data be streamed?

      No doubt it will be, but development cycles in aviation are very long. It takes time to design stuff when the design has to be exactly right. Its not like the work is going to be trusted to Amazon EC2.

    • Antinous / Moderator says:

      Well, for one thing, the possibility that the phenomenon that causes the crash will also stop the data stream early enough to render the system useless.

    • Anonymous says:

      Streaming Flight Data is nearly impossible. Flight Data is a comprehensive set of information records that includes telemetric lectures, voice, condition metrics and measuring, and detailed time synchronization tracks. Streaming that kind of information is too difficult.

      Is not like having a 3G internet connection or something. This is not like having an mp3 file and a txt codified note. Is a complex system of information which really needs an specialized data protocol that nowadays is not supported by any type of wireless conection.

      In the other hand there are thousands of flights daily. There is no infrastructure or financial capacity to assume something like that.

    • Sam125 says:

      I’m not knowledgeable in the matter but if I were to guess, the cost of implementing a data collection policy is enormous and with this find, investigators still have a 100% recovery rate of blackboxes.

    • LightningRose says:

      “Can someone knowledgable explain why air safety investigators have to rely on a hardware black box?

      Why can’t this data be streamed?”

      Mostly it’s a matter of available bandwidth, but here’s a good explanation from a commercial pilot:
      http://www.salon.com/technology/ask_the_pilot/index.html?story=/tech/col/smith/2011/05/06/air_france_black_box_found

    • Anonymous says:

      Wally,
      Recording to tape is much cheaper than streaming through a sat. connection. I live aboard a boat, when not connected to a GSM/3G/Edge signal, i use Inmarsat BGAN (the only Worldwide sat broadband provider) to retrieve my emails and reads news on the net. The cost is more than usd6 per meg !!!
      Air France is a company with no money, that crash is a direct result of bad maintenance. This is due to stupid work regulations in France : working hours are limited to 35hours per week. If you work more, it’s at overtime rates. So Air France can’t actually maintain it’s fleet properly because it would cost them too much in salaries … It’s a well known issue with people working at Air France, but the french “government” will never acknowledge such a fact : ” Sacrebleu, how can you say we are broke, this is France you are talking about !!!”
      BenBen, french national (but i saved my life and now live in asia)

      • Anonymous says:

        So tired overworked people would catch more problems than a fresh pair of eyes? Or is this accompanied by a law that sets a maximum number of employees at Air France? Is there only the one guy or what?

        Also, what about pilots? Don’t they work long and odd hours?

    • Anonymous says:

      Why can the Space Shuttle stream info and commercial airliners don’t?

      Simple: it’s the money.

      Governments will spend the money, while commercial aviation won’t. If the airlines did, you’d see your ticket prices go up.

      Realistically, commercial aircraft seldom crash, and when they do most often it is on land and the ‘black boxes’ are recoverable. It’s only the extremely few flights which crash in the water where recovery of the black boxes becomes problematic.

      In the middle of the ocean the only way you’re going get reliable data transmission is via satellite. Say the FDR and the CVR generate an average data stream of 2Mbps — now go figure out what INMARSAT will charge for that over a several hour period mid-ocean. Now multiply that by the number of flights an airline has over the oceans at any point in time.

  9. Sam125 says:

    Amazing find! Now hopefully investigators will be able to determine the root cause of the of the crash. A tip of the figurative hat to Woods Hole.

  10. SharpieSniffer says:

    Streaming flight data would require monitoring of pilots at work in real time. There is some professional resistance to this kind of oversight. I sort of understand the reluctance to being monitored every second at work but in the case of pilots, I think they should get the hell over it because safety should be the #1 concern.

    • MooseDesign says:

      While that is certainly a cause for concern from pilots and a hot topic right now as there is evidently to be far greater audio and video (so I’ve read but not confirmed) recording of the cockpit in the 787… the data streaming question that came up because of 447 in particular is usually around greater systems status and telemetry data and not simply recording the flight crew actions (although to the point about the pitot tubes it is indeed massively important to know how they reacted to an alternate law state). I think the fact that there were ACARS messages at all is what has even raised the question of real time monitoring in the first place. We got a taste of it and want more…

      Anywho, implementation, monitoring and subsidizing of such a presumably standardized system across hundreds of thousands of flights across the globe is no small task either logistically or financially. I think there is likely a solution out there, but its unlikely that it is immediately around the corner for the vast majority of aircraft.

      Not to forget: part of what makes AF447 of such interest is that it is thankfully an incredibly rare occurrence for a plane to fall out of the air without report, and basically vanish with little trace. Does this incredibly rare incident immediately mandate a reworking of how planes report their location data? Would the associated cost be worth it once its made its way into your ticket price?

  11. dculberson says:

    There’s also the matter of the quantity of data due to the number of flights. NASA has a bit bigger budget per-flight than an airline. There are thousands upon thousands of flights ever day, and streaming the data along the entire flight would require a pretty hefty connection that’s persistent across thousands of miles of unpopulated areas. (I.e. the middle of the ocean in this instance.) The only solution then would be a satellite connection and using that constantly to stream flight data would be really expensive. Of course, the search for this black box was also really expensive, but $30mm wouldn’t go a long way when talking about a persistent satellite network connection for thousands of flights every single day. I imagine more than $30mm would be spent on data every day in that case.

    • Wally Ballou says:

      It would not be necessary to stream every second of every flight.

      If streaming were to be turned on when the plane deviated significantly from the flightplan or normal flight parameters, the volume streamed would be less by a couple of orders of magnitude at least.

      • dculberson says:

        Yeah, I don’t think that would be useful. Mostly for the reason that Antinous suggest. You would need to negotiate a successful TCP connection over a satellite link and then send the data, by the time the connection was negotiated the plane would be in the ocean.

  12. Anonymous says:

    Stellar interview, both the questions and answers.

  13. Anonymous says:

    Just a quick point: It seems it was an engineer and not a scientist that found this. The team lead is credited as an engineer and this is very much a task in engineering.

  14. KingBobo says:

    Thanks for an informative article. Does anyone know whether the actual wreckage location had been previously searched back in 2009 when the locator beacons may still have been active? Given the subsea terrain at the wreckage location, and assuming that the beacons operated as designed, I’m curious to know whether their signals could have been detected, or whether the initial search was simply conducted in the wrong area? From the photos, it looks like the beacon is still attached to the CVR but possibly missing from the flight data recorder.

  15. InsertFingerHere says:

    The next thing that needs to be figured out is why they still use tapes and other sensitive recording materials in those boxes?

    And the endless loop audio recorder.. useless. Record the whole damn flight, that CAN be done with today’s modern solid state gear.

  16. proot says:

    Very interesting interview.

    I’ll have a question, though.
    The picture shows the black box as it was when it was first screened by the search teams.
    How come after two years that heavy thing is not (at least a bit) buried into the sand, or covered with naturally generated sea rubbish?

    • Anonymous says:

      The ammount of sediment that accumulates on the seabed is highly dependent on the specific locality. Places near large river deltas would obviously accumulate very quickly, as well as very biologically productive areas (all those little critters die and snow down). It is not unusual, however, for the accumulation on the seabed in the far open ocean to be measured in millimeters per century, or even less.

      Still, it is amazing that the CVR is just sitting there like it is instead of buried in a mangled pile of wreckage. That plane must have hit the water very, very fast.

    • ackpht says:

      I’ll guess: water very deep, very dark, very still, very cold, little oxygen, and the box is built to resist corrosion. Give it another 98 years and it’ll look like something off the Titanic.

      Cockpit video recorders could help out a lot in accident investigations, because many accidents are caused by pilot error, and even when it is not a factor it would help immensely to see what the pilots did and when. The NTSB has wanted such recorders for years, and the technology is well within reach- but pilots don’t want them, and airlines won’t lift a finger unless the FAA makes them, so we don’t have them.

  17. Anonymous says:

    Remus 6000 picture and specificaition
    http://www.hydroidinc.com/remus6000.html

    Google “Remus 6000 AUV”

    Looks like a topedo

  18. Anonymous says:

    Why don’t they make the flight recorders capable of floating? At least if they were to be floating on the surface of the sea it would be relatively easier to locate them.

    • pao_e_vinho says:

      I think it should be easier to the plane debris and then the recorders than to find a small box floating at the ocean. Besides that, it’s not very common that a plane crashes in such kind off ocean mountain area as happened to this air france plane.

  19. urbanspaceman says:

    Damn, the folks who found the wreck of the Titanic have blown us all clean away again!

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