5 ms·

How long can an airplane's black box last before degrading due to natural causes? Forever? More precisely: Assuming the black box survived the crash intact,

How long can an airplane's black box last before degrading due to natural causes? Forever? More precisely: Assuming the black box survived the crash intact, and assuming that it will be located between 1 and 1,000 years from now, is it guaranteed we'll be able to pull useful data off of it? I wonder what the engineering process is like for one of those things... EDIT: Apparently, the key component of a flight data recorder is its Crash Survivable Memory Unit (CSMU). This manufacturer claims a lifetime of 30 years: http://www2.l-3com.com/edi/crashsurvivable.htm http://www2.l-3com.com/edi/crashsurvivable.htm More info: https://www.aea.net/AvionicsNews/ANArchives/TechSpeakMar10.pdf https://www.aea.net/AvionicsNews/ANArchives/TechSpeakMar10.p... The CSMU is rated for 30 days of saltwater submersion. Obviously, the only scenario it'll be submerged in saltwater outside of the lab is if the recorder's housing cracks. So, assuming the recorder survived the crash, I wonder which would degrade first: The housing or the memory unit? If the housing fails, then the memory unit is toast, since it's only rated for 30 days of saltwater. The manufacturer guarantees the CSMU will last 30 years, but it seems like as long as it stays dry then it might last for much longer. I wonder how long it's theoretically possible to extract useful data off of it assuming it stays dry.

baudehlo 12y ago
Which is really only relevant if it's ever found. The ocean is HUGE.
- melling 12y ago
  Well, if we assume that we're looking for an aircraft with a few large pieces, and it's only a matter of time before cheap autonomous submersible vehicles become common, then it probably will be found some day. Might take a decade or two, but at some point we'll extensively map the rest of the oceans.
  - exhilaration 12y ago
    It might be covered by sediment by then.
    - cnvogel 12y ago
      Obviously there will be huge differences between different parts of the huge oceans, but as a single data point: I've seen photographs taken of the Titanic wreck, where still single shoes can be seen laying uncovered on the ocean floor in the vincinity...
  - baudehlo 12y ago
    I guess the question becomes who is going to pay for these robots? They'll need the ability to dive deep, explore, and then come up for "air" (a recharge). Those aren't going to come cheap. Perhaps the undersea cable conglomerates but it's hard to imagine the use-case for mapping inaccessible areas.
    - MichaelGG 12y ago
      Extend past a few decades. A post-scarcity society would almost certainly search every square metre of the ocean for this airplane, assuming humans are still making decisions.
      - stouset 12y ago
        You say "post-scarcity" like it's an inevitable scenario. Resources are finite. Energy is finite. Exponential growth doesn't last forever.
        toomuchtodo 12y ago
        > Energy is finite. With enough renewable energy from the sun, there is very little we're constrained by http://www.sandia.gov/~jytsao/Solar%20FAQs.pdf http://www.sandia.gov/~jytsao/Solar%20FAQs.pdf "All together, the technical potentials can be estimated to be: Solar electricity: 89,000 TWc · (1-0.708) · (1-0.0345) · (0.3) = 7,500 TWc Solar fuels: 89,000 TWc · (1-0.708) · (1-0.0345) · (0.1) = 2,500 TWc Solar thermal: 89,000 TWc · (1-0.708) · (1-0.0345) · (0.225) = 5,600 TWc These are huge potentials, dwarfing by many orders of magnitude those of the other."
      - baudehlo 12y ago
        Extend past a few decades and you're beyond the lifetime of the black box, sadly. It would be really frustrating to finally find the plane only to never actually find out what happened.
    - melling 12y ago
      Well, the U.S. Navy for one. Just like the air force uses drones, I expect underwater drones to come in quite handy. Submarine tracking, for example.
- JacobAldridge 12y ago
  "Equivalent to finding a pen in San Francisco" - http://www.cockeyed.com/science/flight_370/flight_370.html http://www.cockeyed.com/science/flight_370/flight_370.html
  - mikeash 12y ago
    I don't like that comparison, because when I think of San Francisco I think of lots of buildings complicating the search by requiring you to go floor to floor, but the comparison is just looking at land area, so it's easier than it sounds (but still really tough).
    - JacobAldridge 12y ago
      For mine, the topographical variations of the ocean floor (combined with the fact they're largely unknown, at least to any level of detail) are probably similar to a floor-by-floor search, but you're right than basing it just on area makes for flawed comparisons.
- reitzensteinm 12y ago
  Ever is longer than the ocean is huge :) It may be practically impossible to find with today's technology, but if the next 100 years of progress is anything like the last, there'll be large scale hobbyist exploration of the sea floor. The surface area of the world is 510,072,000 km², 70% of which is ocean. That's absurdly large if you're exploring it with 8 figure submarines, but not at all if you're exploring it with the 2114 equivalents of 2014 $100 aerial drones, especially given a larger, wealthier society with more leisure time.
  - AznHisoka 12y ago
    "especially given a larger, wealthier society with more leisure time." Didn't technology promise that to us 50 years ago? Now we're busier than ever.
    - reitzensteinm 12y ago
      This suggests that's not the case: http://en.wikipedia.org/wiki/Working_time#Gradual_decrease_in_working_hours http://en.wikipedia.org/wiki/Working_time#Gradual_decrease_i... And work aside, think about living life without modern conveniences such as washing machines, dishwashers, fridges and freezers, vacuum cleaners, electric/gas ovens, microwaves, kettles and air conditioning. Running a household a hundred years ago (or fifty years ago depending on wealth) would have been a much more time consuming affair for a significantly lower standard of living. I expect that trend to continue.
- deleted 12y ago
  [deleted]
cnvogel 12y ago
Regarding the saltwater submersion: I think your scenario is not correct. The whole orange thing displayed on that page will be have to be in contact with saltwater. Otherwise the ultrasound pinger (the cylindrical aluminum thing) doesn't even start emitting pulses... (conductive liquid on sensor pads is how they normally detect that they have to turn on) The "lifetime" of 30 years, or 17'000 operating hours is for how long it's certified to run in a non-crashing normally operated airplane. The 30 days in saltwater probably means that no moisture will have crept in through the covers and seals: You can rinse the power-connector and Ethernet with deionized water, let it dry, connect to the computer and read it out. {A assume that these devices are read out much more often in cases of non-fatal crashes where they weren't subject to the elements that much.} The block diagram they show has an separate component for the nonvolatile memory, in a "Crash Survivable Housing". Also I assume that the company at least has some plan for accessing data given a complete disintegration of the memory module, probably by contacting single flash chips. EDIT/ADDED: http://edition.cnn.com/2014/04/23/world/asia/malaysia-370-black-box-lab/ http://edition.cnn.com/2014/04/23/world/asia/malaysia-370-bl... says: """A lot of our work is with undamaged recorders and it's very easy to download them, much as you would a USB memory stick,(...)""" and """One of the most challenging scenarios is when the board itself is damaged: "We could take each individual chip off the circuit board, read those out individually, and then with the help of the manufacturer, piece all that information together,"""
- gsnedders 12y ago
  > {A assume that these devices are read out much more often in cases of non-fatal crashes where they weren't subject to the elements that much.} They're read frequently during maintenance. They are required to be checked to be operable.

baudehlo 12y ago

Which is really only relevant if it's ever found. The ocean is HUGE.

melling 12y ago
Well, if we assume that we're looking for an aircraft with a few large pieces, and it's only a matter of time before cheap autonomous submersible vehicles become common, then it probably will be found some day. Might take a decade or two, but at some point we'll extensively map the rest of the oceans.
- exhilaration 12y ago
  It might be covered by sediment by then.
  - cnvogel 12y ago
    Obviously there will be huge differences between different parts of the huge oceans, but as a single data point: I've seen photographs taken of the Titanic wreck, where still single shoes can be seen laying uncovered on the ocean floor in the vincinity...
- baudehlo 12y ago
  I guess the question becomes who is going to pay for these robots? They'll need the ability to dive deep, explore, and then come up for "air" (a recharge). Those aren't going to come cheap. Perhaps the undersea cable conglomerates but it's hard to imagine the use-case for mapping inaccessible areas.
  - MichaelGG 12y ago
    Extend past a few decades. A post-scarcity society would almost certainly search every square metre of the ocean for this airplane, assuming humans are still making decisions.
    - stouset 12y ago
      You say "post-scarcity" like it's an inevitable scenario. Resources are finite. Energy is finite. Exponential growth doesn't last forever.
      - toomuchtodo 12y ago
        > Energy is finite. With enough renewable energy from the sun, there is very little we're constrained by http://www.sandia.gov/~jytsao/Solar%20FAQs.pdf http://www.sandia.gov/~jytsao/Solar%20FAQs.pdf "All together, the technical potentials can be estimated to be: Solar electricity: 89,000 TWc · (1-0.708) · (1-0.0345) · (0.3) = 7,500 TWc Solar fuels: 89,000 TWc · (1-0.708) · (1-0.0345) · (0.1) = 2,500 TWc Solar thermal: 89,000 TWc · (1-0.708) · (1-0.0345) · (0.225) = 5,600 TWc These are huge potentials, dwarfing by many orders of magnitude those of the other."
    - baudehlo 12y ago
      Extend past a few decades and you're beyond the lifetime of the black box, sadly. It would be really frustrating to finally find the plane only to never actually find out what happened.
  - melling 12y ago
    Well, the U.S. Navy for one. Just like the air force uses drones, I expect underwater drones to come in quite handy. Submarine tracking, for example.
JacobAldridge 12y ago
"Equivalent to finding a pen in San Francisco" - http://www.cockeyed.com/science/flight_370/flight_370.html http://www.cockeyed.com/science/flight_370/flight_370.html
- mikeash 12y ago
  I don't like that comparison, because when I think of San Francisco I think of lots of buildings complicating the search by requiring you to go floor to floor, but the comparison is just looking at land area, so it's easier than it sounds (but still really tough).
  - JacobAldridge 12y ago
    For mine, the topographical variations of the ocean floor (combined with the fact they're largely unknown, at least to any level of detail) are probably similar to a floor-by-floor search, but you're right than basing it just on area makes for flawed comparisons.
reitzensteinm 12y ago
Ever is longer than the ocean is huge :) It may be practically impossible to find with today's technology, but if the next 100 years of progress is anything like the last, there'll be large scale hobbyist exploration of the sea floor. The surface area of the world is 510,072,000 km², 70% of which is ocean. That's absurdly large if you're exploring it with 8 figure submarines, but not at all if you're exploring it with the 2114 equivalents of 2014 $100 aerial drones, especially given a larger, wealthier society with more leisure time.
- AznHisoka 12y ago
  "especially given a larger, wealthier society with more leisure time." Didn't technology promise that to us 50 years ago? Now we're busier than ever.
  - reitzensteinm 12y ago
    This suggests that's not the case: http://en.wikipedia.org/wiki/Working_time#Gradual_decrease_in_working_hours http://en.wikipedia.org/wiki/Working_time#Gradual_decrease_i... And work aside, think about living life without modern conveniences such as washing machines, dishwashers, fridges and freezers, vacuum cleaners, electric/gas ovens, microwaves, kettles and air conditioning. Running a household a hundred years ago (or fifty years ago depending on wealth) would have been a much more time consuming affair for a significantly lower standard of living. I expect that trend to continue.
deleted 12y ago
[deleted]

cnvogel 12y ago

Regarding the saltwater submersion: I think your scenario is not correct. The whole orange thing displayed on that page will be have to be in contact with saltwater. Otherwise the ultrasound pinger (the cylindrical aluminum thing) doesn't even start emitting pulses... (conductive liquid on sensor pads is how they normally detect that they have to turn on) The "lifetime" of 30 years, or 17'000 operating hours is for how long it's certified to run in a non-crashing normally operated airplane. The 30 days in saltwater probably means that no moisture will have crept in through the covers and seals: You can rinse the power-connector and Ethernet with deionized water, let it dry, connect to the computer and read it out. {A assume that these devices are read out much more often in cases of non-fatal crashes where they weren't subject to the elements that much.} The block diagram they show has an separate component for the nonvolatile memory, in a "Crash Survivable Housing". Also I assume that the company at least has some plan for accessing data given a complete disintegration of the memory module, probably by contacting single flash chips. EDIT/ADDED: http://edition.cnn.com/2014/04/23/world/asia/malaysia-370-black-box-lab/ http://edition.cnn.com/2014/04/23/world/asia/malaysia-370-bl... says: """A lot of our work is with undamaged recorders and it's very easy to download them, much as you would a USB memory stick,(...)""" and """One of the most challenging scenarios is when the board itself is damaged: "We could take each individual chip off the circuit board, read those out individually, and then with the help of the manufacturer, piece all that information together,"""

gsnedders 12y ago
> {A assume that these devices are read out much more often in cases of non-fatal crashes where they weren't subject to the elements that much.} They're read frequently during maintenance. They are required to be checked to be operable.