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Malaysia Airlines flight MH370 makes it clear: we need to rethink black boxes

theguardian.com

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Re: Malaysia Airlines flight MH370 makes it clear: we need to rethink black boxes

#91

Post by m4x »

hga wrote: post #67
m4x wrote: post #34

Earlier quoted context omitted.

Real time telemetry via satellite could definitely be useful in some situations. The Air France crash could have been prevented if somebody on the ground had taken a look at the data from the plane, realised that the junior pilot has been pulling up the whole time, and made the crew aware of it. That was one of the worst crashes in history and there was never even a problem with the plane. All they needed to save the…

That's demanding rather a lot from a human on the ground. The Boeing (and I'm sure others) design philosophy is "unsynchronized joysticks ARE A TERRIBLE IDEA", and if Airbus and Air France had use the normal synchronized yokes, the problem of the brain wedged junior pilot would have been quickly apparent. Can you think of other examples? BTW, it's guessed that iced up pitot tubes caused the autopilot to disengage. Yo…

I agree that a better fix would have been to have synchronised joy sticks, but that doesn't negate the usefulness of telemetry

I'm aware that the pitot tubes iced over, but they de-iced long before the point of no return

And I bet the pilots would have listened to a 'kibitzer'. The senior pilot actually told the junior one to stop pulling up, knowing it would cause problems, and would presumably have taken control more forcefully if he'd been aware that the junior pilot had resumed pulling up after bein asked to stop. He just didn't know. Better communication, syncd joysticks or telemetry could all have helped make him aware of that.

Re: Malaysia Airlines flight MH370 makes it clear: we need to rethink black boxes

#92

Post by sliverstorm »

pcurve wrote: post #23
brandon272 wrote: post #7

I'm seeing a lot of armchair criticism aimed at the air travel industry about how these aircraft should be able to be tracked more effectively given "modern technology" and they reference things like broadband in cars, WiFi on flights, etc. What they seem to ignore is that many of these things only work effectively on land in populated areas. Drive your car out to the South China Sea and let me know how well the in-c…

In both Air France 447 and Malay Air MH370, local authorities found traces of crash / wreckage within 1-2 days. People don't fully appreciate how difficult it is to find anything in the middle of ocean when there's no visual trace. Even if you can narrow down the point of impact within a few square miles, you won't know for sure until you get underwater equipment. When you're dealing with deep underwater recovery, al…

local authorities found traces of crash / wreckage within 1-2 days.

Yeah, but our attention spans only last about 12 hours! You expect us to wait that long!?

Re: Malaysia Airlines flight MH370 makes it clear: we need to rethink black boxes

#93

Post by lotsofmangos »

mcintyre1994 wrote: post #22
curtis wrote: post #4

I think one of the lessons of Air France 447 is that our existing black boxes not only work, they work extremely well. So it's not so much that we want to replace our current black box technology so much as we want to augment it. A live satellite feed is an obvious choice here, but I'd argue that a secondary backup black-box (presumably 100% solid state these days) located in a part of the airplane that's likely to f…

Is there any part of a plane likely to float with a black box attached to it? I can't find data on Google, but I'd guess they're pretty heavy?

You could have several bright orange foam blocks containing memory and a radio beacon on the outside of the plane that detach in water. You then send blackbox data to them using em loops inside the fuselage. That would be pretty cheap and would also help in mapping debris on land.

Re: Malaysia Airlines flight MH370 makes it clear: we need to rethink black boxes

#94

Post by selectodude »

ghshephard wrote: post #72
joering2 wrote: post #59

The issue here is a monetary one. How many planes go down each year? A few. How many planes are never found (black boxes). One per 10-15 years? An airline, or a company that builds planes would have little to none problem explaining to the judge that benefit-cost analyse make no sense: too much money would be spent for too little benefit (I know lives may be at stake, but that won't convince the judge). Couple years…

"I know lives may be at stake" What lives are at stake? An enhanced black box won't prevent accidents, and, with very few exceptions, it won't help us find out the cause of accidents. I think your take on the "cost-benefit" analysis made the most sense. Your 1 in 17 million scenario is interesting - how many times per flight is that scenario evaluated, or is that per flight? If per flight, and suppose we have about 2…

I think the chances that the conditions are right are 1 in 17 million, however the chances the fuel ignites is also extremely low.

Re: Malaysia Airlines flight MH370 makes it clear: we need to rethink black boxes

#95

Post by wglb »

fnordfnordfnord wrote: post #88
wglb wrote: post #81

Earlier quoted context omitted.

Keep in mind that over-the-horizon radio communication is subject to the vagaries of the ionosphere and is not totally reliable. Further, there is a day/night difference, and a dependence on latitude. Line of sight at 30000 feet is about 200 miles, so there are huge areas where everything is over your horizon.

But don't most actual aircraft flight paths tend to stay near land? For those flights that must go over that horizon, couldn't they fail over to a lower freq / lower bandwidth channel, when needed; while still keeping near real-time status updates? Or connect via another aircraft who is further behind them but on a similar flight plan. Here is probably one of the worst flight paths for this type of potential comms ht…

Well, for the ones that travel within sight of land, we don't have much of a problem. And that may be "most". But "most" flights don't end in disaster. It is the ones that spend long hours over the horizon that are of the most concern.

A significant number spend lots of time more than 200 miles from land. And "land" here means some land with a data link endpoint.

With respect to airplanes forming some sort of mesh network, consider the bandwidth requirements throughout this link.

Re: Malaysia Airlines flight MH370 makes it clear: we need to rethink black boxes

#96

Post by sliverstorm »

fnordfnordfnord wrote: post #88
wglb wrote: post #81

Earlier quoted context omitted.

Keep in mind that over-the-horizon radio communication is subject to the vagaries of the ionosphere and is not totally reliable. Further, there is a day/night difference, and a dependence on latitude. Line of sight at 30000 feet is about 200 miles, so there are huge areas where everything is over your horizon.

But don't most actual aircraft flight paths tend to stay near land? For those flights that must go over that horizon, couldn't they fail over to a lower freq / lower bandwidth channel, when needed; while still keeping near real-time status updates? Or connect via another aircraft who is further behind them but on a similar flight plan. Here is probably one of the worst flight paths for this type of potential comms ht…

You can't just "fail over to a lower freq". Propagation beyond the radio horizon at all is at the whim of the ionosphere, which is the only reason long-distance radio works in the first place (it reflects back down, when the conditions are right)

Re: Malaysia Airlines flight MH370 makes it clear: we need to rethink black boxes

#97

Post by teamonkey »

From what I understand, what makes this (probable) crash unusual is that nothing was received from the plane. Modern airliners send out all sorts of signals over several channels. The data that sites like FlightTracker uses are part of it.

In the case of the Air France crash, telemetry data was sent out in the good 15 minutes it took to go down. With this flight - nothing. One moment it was sending data saying all was well, the next it simply disappeared from the screens. Extremely unusual. If there was a sudden disintegration of the aircraft, there's a good chance an internet-based device would go offline too.

I believe the black box has a signal that will let it be found but it only has a range of 1-2km - less underwater.

Re: Malaysia Airlines flight MH370 makes it clear: we need to rethink black boxes

#98

Post by brandon272 »

pavelrub wrote: post #74
brandon272 wrote: post #7

I'm seeing a lot of armchair criticism aimed at the air travel industry about how these aircraft should be able to be tracked more effectively given "modern technology" and they reference things like broadband in cars, WiFi on flights, etc. What they seem to ignore is that many of these things only work effectively on land in populated areas. Drive your car out to the South China Sea and let me know how well the in-c…

I'm not convinced by your argument. I'm not sure what you mean by 'something catastrophic happens'. 'Something catastrophic' is the result of a certain chain of events. Telemetry data about those events can be sent before they lead to 'something catastrophic' that makes it impossible to send anything further. It is not as if the plane hits a meteor in mid flight and everything suddenly explodes with no prior indicati…

I'm not thinking of meteors when I describe a "catastrophic" event. I'm thinking of a fuel tank explosion like TWA Flight 800 or a missile hitting the plane or a bomb in the cargo hold going off or a stress fracture on the fuselage causing an inflight breakup. None of which have been ruled out on the Malaysian flight, I should add.

Re: Malaysia Airlines flight MH370 makes it clear: we need to rethink black boxes

#99

Post by [deleted] »

akiselev wrote: post #53

I totally agree with making black boxes more advanced to phone home and such, but this line annoyed me: "Your iPhone is more powerful than the evidence-collecting computers in the cockpit. Simple changes could mean faster answers for plane crashes" You're talking about the black box for a airline jet. This thing is supposed to survive plane crashes; not just being dropped a meter off the floor, but smashing into the…

[deleted]

Re: Malaysia Airlines flight MH370 makes it clear: we need to rethink black boxes

#100

Post by retroencabulato »

yaakov34 wrote: post #20

Let's start estimating the technical challenge here (we're supposed to be techies, after all). Bandwidth: quick googling shows that a flight data recorder records between 64 and 256 12-bit words a second, i.e. 1-3 kbps. Browsing http://en.wikipedia.org/wiki/Bit_rate shows that another 2-8 kbps is needed for voice recording (from one microphone). Let's call it 10 kpbs all together. Number of simultaneous connections:…

Actually there is a large body of people looking to use cubesats as ADS-B receivers: http://mstl.atl.calpoly.edu/~bklofas/Presentations/SummerWor... (PDF Warning)
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