Aircraft Black Boxes
Discussion
spikeyhead said:
If they aircraft is knackered, would you really want to rely on it's satelite link? most of the pacific and atlantic are out of radio range.
Totally off thread, but when flights are out over the middle of the oceans, are the effectively in radio-silence? For some reason I always though contact would be maintained (somehow)
CatfishCKY said:
I thought planes never ventured straight out over the ocean? Like when we went to Florida the plane went up towards greenland and Iceland and the down past Washington dc into Sanford airport iirc
I'm fairly sure they did that because the curvature of the Earth makes it a shorter distance than the visually more direct path over the ocean.Matt UK said:
spikeyhead said:
If they aircraft is knackered, would you really want to rely on it's satelite link? most of the pacific and atlantic are out of radio range.
Totally off thread, but when flights are out over the middle of the oceans, are the effectively in radio-silence? For some reason I always though contact would be maintained (somehow)
I think the only "aircraft" using data relay instead of a black box is the Space Shuttle. It is unclear whether NASA has ever published all of the data received during the break-up of Challenger and Columbia.
Having said that, I don't know whether all military aircraft use a black box. Seems to me there would be a significant risk of giving away classified flight performance information if the "other side" recovered a black box from a downed jet.
Having said that, I don't know whether all military aircraft use a black box. Seems to me there would be a significant risk of giving away classified flight performance information if the "other side" recovered a black box from a downed jet.
Baffled Spoon said:
CatfishCKY said:
I thought planes never ventured straight out over the ocean? Like when we went to Florida the plane went up towards greenland and Iceland and the down past Washington dc into Sanford airport iirc
I'm fairly sure they did that because the curvature of the Earth makes it a shorter distance than the visually more direct path over the ocean.I flew to the Caribbean and back last month and literally followed a straight line from Heathrow to the destination. You try not to think about it but when you see the little image of the plane on the screen and you're around 1,500 miles from the nearest decent sized chunk of land.
spikeyhead said:
I don't think so, been ages since I've even half looked at aircraft comms, see the Air France plane that fell into the Atlantic a couple of years ago, it's been in the news again recently as it's only just been found.
http://en.wikipedia.org/wiki/Aircraft_Communication_Addressing_and_Reporting_SystemThe Air France flight was transmitting ACARS maintenance messages across the ocean until the last, detailing loss of cabin pressure and multiple failures... all pretty chilling.
So yes they can be in contact. But that's just text based messages, the black box records all communications and all activity in the cockpit, along with every single sensor output, control inputs... etc. Faaaarrr too much data to be trasmitting via sat x every flight in the world.
If you have a few hours, read this cover to cover:
http://www.pprune.org/tech-log/395105-af-447-searc...
One records flight data, one records cockpit speech and sounds. I don't know anything about communications, but that's a hell of a lot of information for every airborne aircraft to be transmitting continously.
CatfishCKY said:
I thought planes never ventured straight out over the ocean? Like when we went to Florida the plane went up towards greenland and Iceland and the down past Washington dc into Sanford airport iirc
Google something called ETOPS. It's a regulation about how much flight time you can be from a suitable airport with an engine out. AFAIK aircraft are usually in contact with someone even over large stretches of water. I assume using HF rather than VHF. ETOPS (Extended Twin Operational Performance Standards) allows twin engine operations up to 3 hours flying time from the nearest emergency diversion, if I recall correctly. I think there's one particular polar or pacific route where this is currently extended to 207 minutes. There are moves afoot to extend further to 300+ minutes for future models.
No thanks.
No thanks.
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