I haven’t had much to say on the disappearance of Malaysia Airlines Flight 370, because I’ve got no particular aerospace expertise and thus had nothing useful to add to the speculation. But I do know something about modern telecommunications, and so all this talk about attempting to track the plane via pings and other automated transmissions to various satellite and ground-based receivers, got me thinking: in this day of on-board WiFI Internet connections, why are we still relying solely on an aircraft’s “black box” for a record of its final minutes or hours?
This instrument data is simply too important to be left at the bottom of a deep-sea trench, so why isn’t it constantly being transmitted real time via satellite as a kind of off-site backup? Cockpit voice recordings too. All of it compressed and securely encrypted. With no means of turning off the transmission. The technology is there. The satellites are there. Isn’t this a totally obvious solution?
Am I missing something here? Are there any experts out there who can explain why we don’t already do this?
It wouldn’t take much more than the whim of federal and international regulators to mandate this virtual black box on all modern jetliners. And given the low cost of telecommunications technology, it wouldn’t add much to the cost of flying. But it would provide closure for the families of victims of future crashes, as well as valuable data on how to prevent a repeat.
Some airplanes provide a richer communications stream than that provided by the 777 of MH370.
Black boxes can be made to be more self contained. Communications streams require antennas, which may not be in close proximity to the source of data to be transmitted.
The BBC has a short interview with Inmarsat’s senior vice president for external affairs, Chris McLaughlin. He says aircraft could report location, speed, and heading “every 15 minutes” for $1 an hour using existing technology.
I don’t believe their are enough satellites to deal with the amount of data that would need to be passed from all the planes in flight.
The cost of setting up such a system would be fairly high, and I’m not sure who would be willing to foot the bill. Especially given how rare an occurrence like this is. If you need to spend billions to set up and maintain the system and you only need it a few times a decade, is it really worth it?
@3 The satellite system is there, and you only need to transmit some of the data with limited resolution to make this extremely useful. Alternatively, you could trigger fuller transmission in the case of an in-flight emergency. There are solutions. It just doesn’t make sense that some sort of automated transmission isn’t permanently on.
On an aviation site there is some controversy about what it actually costs to communicate data via satellite. And of course while planes are in radio range they don’t need satellites. Two big modern planes have gone down recently in isolated parts of the oceans. Some sort of minimal communication is needed.
What makes you think the NSA doesn’t already do that? I’m pretty sure they have an agreement with Boeing along those lines in exchange for helping spy on Boeing’s competitors…
“Am I missing something here?”
Cost. At least, that’s the excuse the media gives us.
999-year exclusive contract with the black box maker?
Because the last major revision to the black box was in the early 90s and maybe they really are due for an update ?
http://www.l-3ar.com/html/history.html
FWIW, flight 447 caused one electronics/software engineer to suggest what you’re suggesting about 4 years ago.
http://spectrum.ieee.org/aeros.....-black-box
Instead of storing flight data on board, aircraft could easily send the information in real time to the ground
By Krishna M. Kavi
Posted 30 Jul 2010 | 12:45 GMT
Here’s a NYT article that talks about the cost: ‘The Technology Is Out There,’ but Satellites Don’t Track Jets
The best discussion of this was by James Fallows in The Atlantic here, on March 14th. Read the whole thing for the economics and technical aspects (VHF vs. HF vs. satellite radios, available bandwidth, etc.), but the relevant point here is not that we need to constantly stream all the data pouring forth from flight systems, it’s that we don’t want to lose track of the damn planes themselves. If you know where the plane is you can intercept, if flying, or recover, if crashed. As one of Fallows’s correspondents says:
And inexpensive, and wouldn’t require a bunch more infrastructure. But you want the transmitter(s) COMPLETELY inaccessible in flight, so you can’t turn it off from the flight deck or climb down to the radio rack in the avionics bay and disconnect it there.
Seems doable. And flight-data recorders can, for the time being, keep doing what they’re admirably and ruggedly suited to do.
Why is it more important to do this for the rare airplane that is lost?
Wouldn’t it make more sense to wire very automobile?
Guaranteed that if airplanes have an electronic device that can’t be turned off, there’ll be a fault that leads to a fire, with no way to remove electrical power. Never a good idea on an airplane.
What Fallows’s correspondent describes (quoted @11) is using existing systems to send GPS location every few minutes. Yes, @13, radio fires can happen. But the Malaysia Airlines case shows the likelihood that transmitters were deliberately disabled, so it may ultimately be desirable to add low-cost Personal Locator Beacon-type GPS transmitters (~5W burst transmission) that are battery-powered, self-contained, well-isolated within the aircraft (i.e., inaccessible), and activate automatically if breakers are turned off.
There’s actually a good chance that the problem with MH370 was indeed a fire.
and that the transmitters were deliberately turned off as part of the process of fighting it.
Some customers do order planes equipped with ELTs (Emergency Locator Transmitters). Various reports speculated that MH370 might have had at least two – one near the front that activates by a 2.5 G deceleration, and one near the tail that activates by submersion. Some airlines also have emergency beacons on the life rafts.
Apparently some crashes fail to activate these devices, or they are destroyed by the impact, or they sink before establishing contact with the SAR satellites, etc.
All airliners have ELTs. The problem is they all too frequently fail to activate in a crash. They are totally automatic with a charging circuit but powered by a battery so they can’t be turned off like the ATC transponder. Location of the plane is the key. The amount of data that is going to an FDR is massive and it’s not practical to upload that via a data link.
Systems failures in the plane or active attempts to control an emergency situation could cause the shutdowns of comms seen.
I find that last unscheduled partial handshake from ACARS very intriguing. I wonder if that happened when the plane was running out of fuel and a lot of power switching was going on as the plane automatically moved electrical load around….kind of like cycling power and a hard reboot.
I’ve been partial to the ghost plane hypothesis and I’m still sticking with it. I’m not absolving the crew….they could have screwed up during the whole process during an emergency. Look at Helios flight 522. A screwup by the crew knocked out the crew and pax, and it went ghost plane on autopilot until it ran out of gas. A flight attendant did make a futile effort to take control but it was too little too late. http://en.wikipedia.org/wiki/H.....Flight_522