beschizza — 2014-03-21T12:32:02-04:00 — #1
jandrese — 2014-03-21T12:41:34-04:00 — #2
The big issue is that satellite time is limited and expensive and airlines are in perpetual financial crisis. It's an extremely rare event when a disaster like this happens.
That said, a really low bandwidth solution (tiny burst updates every 15 minutes or so) seems like it could be workable.
seyo — 2014-03-21T12:47:18-04:00 — #3
Everyone who already has a GPS enabled smartphone can already provide it for free. I don't understand why this isn't being exploited.
jandrese — 2014-03-21T12:56:20-04:00 — #4
Smartphones transmit data using terrestrial cell networks, those don't work when you're at FL400, especially when you're over the ocean.
pixleshifter — 2014-03-21T13:17:41-04:00 — #5
But a mobile with GPS retrieves its own location position, it's passive. and surely the plane already has constant broadcast capabilities?
Receive coordinates, then transmit on regular frequency.
peregrinus_bis — 2014-03-21T13:18:16-04:00 — #6
Short wave bursts, flight code (secure), gps location, status?
I was thinking about this, and one thing might be the military would requisition aircraft in the event of war. Having a pinger that you can't disable would slow re-deployment of the craft while they ripped it out.
(am I going bonkers?!)
stebuu — 2014-03-21T13:19:09-04:00 — #7
If companies can make a profit selling plane-ride long internet service for $14, I don't think the chief hurdle to the idea is the cost of maintaining the data connection.
brian_carnell — 2014-03-21T13:23:25-04:00 — #8
It might make sense to spend the money if air travel was as dangerous as automotive travel, but its not,
Globally, last year  was the safest since 1945, with 23 deadly accidents and 475 fatalities, according to the Aviation Safety Network, an accident researcher. That was less than half the 1,147 deaths, in 42 crashes, in 2000.
In the last five years, the death risk for passengers in the United States has been one in 45 million flights, according to Arnold Barnett, a professor of statistics at M.I.T. In other words, flying has become so
reliable that a traveler could fly every day for an average of 123,000 years before being in a fatal crash, he said.
Also, remember each new technology imposes potential new risks. The fire issue with adding new electronics is one thing (but likely easily mitigated), but there are also a number of security problems with the way these new tracking standards, such as ADS-B, are being implemented. There was a Defcon presentation last year about just how bad these changes are from a security POV (think...no encryption or authentication of data that planes will be sending and receiving under current Next Gen air traffic control schemes).
simonize — 2014-03-21T13:29:55-04:00 — #9
Yeah, not too many cellphone towers in the Indian Ocean. Knowing where the plane IS isn't the technical difficulty here. It's communicating that information for EVERY airliner, ALL the time that is the issue. Short bursts of info would have to be timed so that they didn't interfere with each other. Unlike local air traffic control, we're talking about a system that works over REALLY Large areas so that is many more aircraft whose signals would have to be coordinated. And that's true for both satellites and shortwave. After all the only reason that cell phones have become ubiquitious is that the cells are small and the same frequencies can be reused just a few miles away. ...Of course the maintenance system on this plane was already doing this and there IS an available enhancement which would have added GPS coordinates to the that signal, so it certainly IS possible. But how much more difficult this would be if EVERY airliner was doing this I don't know. There's only so much spectrum available.
jandrese — 2014-03-21T13:31:02-04:00 — #10
I should also point out that the 777 already has the capability to do this, but it's an optional feature and the airline didn't buy it. That's the main reason we know it continued to fly for as long as it did, because of the hourly pings to the satellite checking for service.
stephen_schenck — 2014-03-21T13:31:59-04:00 — #11
So, ADS-B, but with a satellite relay?
jandrese — 2014-03-21T13:38:50-04:00 — #12
It's possible they could use a system like Omnitrax that is commonly used on long haul trucks and shipping containers.
Next time you're driving down the interstate and pass a truck, look on top of the cab. There's a decent chance you'll see a white radome on top of it. This is the satellite uplink used to report tracking data to the shipping company. The data rate is really slow (one 1500 byte packet every 15 minutes), but the service is relatively affordable.
rocketpj — 2014-03-21T13:45:35-04:00 — #13
I really, seriously doubt we lack the capacity to track every single airplane that is in the sky, at all times. With the possible exception of Antarctica (over which few missiles are likely to pass), I think the entire planet is under satellite coverage pretty much all the time.
I have little doubt that total information awareness must include total knowledge of planes in the air, right down to the littlest Piper Cub on a fishing trip in Siberia. The technological capacity exists, though perhaps not in orbit just yet.
I further find it unlikely that, if the US data trackers are not yet covering the whole planet, they aren't at least tracking every single airplane that departs from a predominantly Islamic country, if only because of paranoia and relatively recent events.
l_mariachi — 2014-03-21T14:06:42-04:00 — #14
It could be disableable but only on the ground, i.e. not from inside the plane.
jandrese — 2014-03-21T14:14:27-04:00 — #15
There are some fundamental physical limitations we have to consider here. Spectrum is a limited resource, although an airplane should be able to use really high frequencies because you don't have to worry about them going under bridges or trees too much. The limited space for a dish means you won't be able to get a 1 degree beam up to Geo orbit, so you'll have to spread spectrum your signal and cut way down on the data rate. The high frequency helps here as well, you can get by with a smaller dish. Of course all of this really high freq gear costs more and is more sensitive to vibration. It's a tradeoff.
That said, Omnitrax can track a bajillion trucks already, so this is largely a solved problem. The unsolved problem is how to prevent airlines from being such cheapskates.
bcsizemo — 2014-03-21T14:18:32-04:00 — #16
It looks like to me it'd be easier to have a peer/mesh network than actually try and broadcast up to a satellite. The system could easily adjust network transmission direction and power since it would be in fairly regular contact with another plane. Ground wouldn't necessarily need real time updates, but should be able to easily get them as long as another plane was with in range.
peregrinus_bis — 2014-03-21T14:25:47-04:00 — #17
Right - it would transmit at whatever interval, but also freak out and start chattering when there were any problems
marc45 — 2014-03-21T15:30:54-04:00 — #18
There is no good reason. You can buy off the shelf units (Spot) that for a nominal yearly fee will track your location via satellites and send this to the company every few seconds. The yearly subscription cost is less than 1 minute of fuel burn in large jet.
gordwait — 2014-03-21T17:13:40-04:00 — #19
Considering the Snowden revelation that every one of our cellphones in North America is being tracked, it would be insane that the NSA know where your cellphone is right now, but don't know where only one of some 700 Boeing aircraft is at any time.
After 9/11, I would assume the very first "todo" would have been to pay a visit to Boeing with a Presidential secrecy order and a crate of satellite transponders.
So the question becomes "Why aren't government intelligence agencies telling the press where the plane went?".
steve_nordquist — 2014-03-21T18:42:33-04:00 — #20
Since it was a 777, perhaps it met an adversary and the 62 consecutive hits for 7777HP have not completed? Heal up after, Captain Frog!
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