Jon Ison
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| posted on 2/6/09 at 05:51 PM |
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Airbus down & my ignorance
I had the taken for granted misconception that anything in the air was tracked ?
I had this idea in my head that planes passed from air controller to air control as they flew through different bits of airspace and where monitored
via radar or some other means ?
Obviously not, was anyone else under this misconception, not that i read it anywhere just sort of assumed ?
So mid Atlantic and your on your own ? Who / what keeps the aircraft in "flying lanes" fro example over the Atlantic or other non
monitored airspace, or is it monitored and I'm missing a point somewhere ?
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Hellfire
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| posted on 2/6/09 at 05:55 PM |
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Must admit, I'd always thought they were monitored. I also thought that the black box they carry are virtually indestructable and contained some
sort of transmitter to enable tracking. Obviously not the case though I guess, otherwise the plane wouldn't have gone missing 
Phil
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mr henderson
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| posted on 2/6/09 at 05:57 PM |
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I'm surprised that they don't automatically transmit their position as found by GPS. Computer listens to the transmissions, records them,
then if a plane goes missing, check the computer, last recorded postion is where to start looking. Seems straight forward enough
John
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iank
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| posted on 2/6/09 at 05:58 PM |
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The plane knows where it is (from GPS) down to 25m or so and the altitude. It also knows the route it's supposed to be taking - and the
autopilot keeps it on route in the flight lanes - pilots only really do the take off, landing and emergencies these days.
When planes go over borders they get handed onto the new countries air traffic control which is what I think you're thinking of.
Ocean's are big places and I can quite believe there are big patches that aren't covered by civil radar - don't know about the
military coverage.
--
Never argue with an idiot. They drag you down to their level, then beat you with experience.
Anonymous
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JoelP
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| posted on 2/6/09 at 05:59 PM |
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the captain, i guess.
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iank
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| posted on 2/6/09 at 06:01 PM |
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quote:
Originally posted by Hellfire
Must admit, I'd always thought they were monitored. I also thought that the black box they carry are virtually indestructable and contained some
sort of transmitter to enable tracking. Obviously not the case though I guess, otherwise the plane wouldn't have gone missing
Phil
Black (really orange) boxes do have a locator beacon which comes on when it hits water (range around 2miles so the guy on the radio said)
unfortunately it's anything up to 1.4 miles down to the bottom in that part of the atlantic - so they need to be close on the surface to find
it.
Battery lasts a month so there's going to be a bit of a race to find it.
--
Never argue with an idiot. They drag you down to their level, then beat you with experience.
Anonymous
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oldtimer
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| posted on 2/6/09 at 06:01 PM |
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A satelite tracker seems so obvious and cheap.....It could, of course, be FAB or, the Brazilian Airforce as we know them, who are famous for their
incompetance. Not that poor tracking has caused the crash.
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eznfrank
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| posted on 2/6/09 at 06:02 PM |
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On some of the transatlantic flights you can listen in to the flight deck and hear the pilots talking to air traffic and other planes. On the ones
I've been on they never seem to be out of contact with "someone" for more than a few minutes.
From listening in they tend to be told to follow xx heading at whatever altitude and then check back later.
I do remember one pilot asking another pilot who was entering US airspace to check the scores of a hockey game and get back to him!!!
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Guinness
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| posted on 2/6/09 at 06:03 PM |
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I have heard some interesting stories about planes flying between Europe and South Africa.
Basically in European airspace everything is very tightly controlled. Once you get down to the top of Africa, it's a bit more, shall we say,
relaxed? (Air traffic control go home at 5pm?)
Then the planes are pretty much left to their own devices until they reach South Africa.
There are several flights from Europe (one from each capital city?) down to JHB each night. They all stay in radio contact with each other to ensure
they are all OK / know where each other are.
As I say, just what I've heard.
Mike
P.S. The black box will have been manufactured to survive any incident. However if it's in seriously deep water the range of the transmitter
will be limited.
My thoughts go out to all those lost and their families.
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Badger_McLetcher
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| posted on 2/6/09 at 06:04 PM |
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Radar only covers and tracks within a certain range of land, especially in areas without very powerful military units.
As for the GPS thing, some a/c do, some don't. It's still a relatively new technology and it can take the aicraft industry a hell of a
long time to adopt something which doesn't turn a profit. The black box is pretty hard to destroy, however some parts can still be damaged. The
idea is that enough survives to allow investigators to find what went wrong. It does have a beacon on it, but it may be difficult to track given
it's current location and/or weather conditions.
If disfunction is a function, then I must be some kind of genius.
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Jon Ison
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| posted on 2/6/09 at 06:14 PM |
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First off I echo Guinness's comment, my thoughts to are with the families and friends of those missing.
It just came as a surprise to me they do not know the last position of the aircraft, as I said I just assumed 500mph projectiles would be tracked, Ive
seen to many movies.
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mad4x4
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| posted on 2/6/09 at 06:35 PM |
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When I was down in Nigeria few years back they lost a 747 - from the airport. Because some locals nicked it. Just fired it up taxi'd it down
the runway and flew off .
Nigeria doesn't have any radar in Port Hardcourt
Scot's do it better in Kilts.
MK INDY's Don't Self Centre Regardless of MK Setting !
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eddie99
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| posted on 2/6/09 at 06:40 PM |
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I heard it was moving areas to differnt air traffic personal when it went missing, it told one place it was going to the other and they never got
confirmation
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NOTE:This user is registered as a LocostBuilders trader and may offer commercial services to other users
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SteveWalker
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| posted on 2/6/09 at 06:47 PM |
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Over the oceans, its just a case of sticking to your allocated flight levels and courses, the radar does not reach out there - in case of error, the
aircraft's own anti-collision system will warn of other aircraft, but this relies on each aircraft telling the others where it is. Even in
Europe I think that most air traffic radar is not actually radar, instead it sends out requests and the plane sends back it's identification,
location, height, heading and speed automatically. Only if a plane is not responding or giving obviously erroneous information is proper primary radar
used instead of this information.
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jeffw
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| posted on 2/6/09 at 06:53 PM |
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Military Land (or Sea) based air search radars are limited to around 200-250 miles and only at that range for relativley high altitudes. Radar is a
line of sight technology and is limited by the curvature of the earth. This is why armed forces use airborne early warning systems of which AWACS are
an example.
Radio transmission (expect Very Low Frequency) don't travel very far in water. I would be surprised if a 'black box' could be
detected at more than a few miles once it was sunk off the continental shelf.
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SteveWalker
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| posted on 2/6/09 at 07:38 PM |
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I could be wrong, but I thought that the black boxes gave off a sound too, which of course travels well underwater.
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dave1888
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| posted on 2/6/09 at 08:12 PM |
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Not all airlines are allowed to fly over the atlantic due to there maintenance records not being upto spec, there was one airline lost there
permission to fly the atlantic last year. I remember being on a Virgin atlantic flight a few years back from Manchester to Las Vagas its route taken
was over the UK, Greenland, Canada then US. Seemed a strange and long route to take but the reason behind it was never more than an hour from an
airport.
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jeffw
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| posted on 2/6/09 at 09:17 PM |
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Sounds does indeed travel through water well, however it has issues passing through thermocline barriers (water at different temperatures). To be
able to hear a sound underwater you would need to be in the same temperature band of water.
This is how submarines hide from surface ships and helicopters passive sonar systems and why there is a requirement for towed arrayed sonars for
surface ships and dipping sonars for helicopters to enable them to breach the thermocline.
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bilbo
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| posted on 2/6/09 at 09:24 PM |
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I've been talking about this to a guy I know who's an Airline captain.
In that neck of the woods (i.e mid atlantic in international waters), as said before, there is no radar, and no one round there wants to pay for it.
Comms are only via radio.
What I didn't know is the 'black' box not only has a radio beacon, but also a sonar 'ping' that should last a month - so
once they get the general location (which I think they have now), they should be able to zoom in on it quite quickly.
Oh, and the 3 mins of auto data transmissions re electrical faults etc - he thinks that was just the planes death rattle as it fell apart, rather than
it reporting a direct cause
---------------------------------------
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jeffw
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| posted on 2/6/09 at 09:27 PM |
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"The black boxes from the missing Air France jet are crucial to determining what brought the plane down, but locating the devices could present
the most daunting challenge since the Titanic mission, Reuters reports. “You are looking for a needle in a haystack,” said one industry specialist,
guessing recovery could take months, especially if the boxes are beyond divers’ reach.
One oceanographer says the boxes, which record cockpit conversations and instrument data, could be more than 13,000 feet below surface—far exceeding
the 2,000-ft. maximum appropriate for submarine rescues. “You will be pushing the limits of the technology,” he said. Despite the challenges, though,
giving up isn’t an option, an expert insists: “Not knowing would be totally unacceptable.” "
They will need to locate the Box and then use a unmanned submersible to recover it. I used to maintain a system that was capable of 12000 metres
depth so 13000 ft isn't that big an issue....finding it will be however. I was slightly involved with the recovery of an Air India 747 black
box that went into the Atlantic 23 odd years ago.
Even if these devices give off active sonar now it will be difficult to locate because of the thermocline layers and the sonar will not last very long
given the power that is required for a sonar pulse to go any distance.
It is likely they will need to sweep the seabed in the area of the crash with side scan sonar to identify the major parts of the aircraft and from
there recovery the black box (of which there are a number in the plane I believe).
[Edited on 2/6/09 by jeffw]
[Edited on 2/6/09 by jeffw]
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MikeRJ
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| posted on 2/6/09 at 10:18 PM |
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I saw a program on Discovery recently about South African Airways Flight 295
that crashed in the Indian sea. It took months to find the black boxes, by which time the radio beacons had stopped working, and in the end the US
recovery team had to get extra long cables made for the ROV as the plane was something lke 16,000 feet down.
Pretty incredible what can be done, if you have the resources to throw at it.
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alistairolsen
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| posted on 2/6/09 at 11:18 PM |
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is it just me that would have made the reinforced black box have a specific density less than one?
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jeffw
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| posted on 3/6/09 at 05:10 AM |
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No good if it is still attached to the aircraft.
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