Whenever there’s an airline crash, either on land or water, the first task is an exhaustive search for the ‘blackbox’, which as I understand it is actually 2 seperate recorders: voice-cockpit recorder and flight-data recorder. Given that these instuments are vital to determining the cause of a crash, and given that it can sometines take days or weeks to loctae (the bottom of the ocean being a rather large place), my question is:
Why aren’t the relevant data transmitted to a ground-based receiver which could record it, and then if necessary erase it once the plane lands safely (for all of you the-data-would-take-too-much-space cynics out there)?
In the event of a crash, the FAA could have the data in seconds, rather than days, weeks or never. Surely this is possible? A series of ground-based relay stations, or even a satellite based receiver/transmiiter could cover the globe, as modern radar does now, and capture anything the flight recorders do, no?
Usually planes crash for a reason involving one or more systems breaking. If, for example, the plane lost all electrical power, or the radio set just broke; there would be no radio transmission. Plus, usually there is a X second period between loss of contact with the plane and the creation of a big mess on the ground. Those last seconds might be critical to determining what led to the crash.
I have wondered this myself, and while Wonko’s reasoning seems sound, I think there are other reasons.
My WAG is that the sheer quantity of data which would be needed to give investigatiors a decent picture of what’s going on is too much to broadcast from a moving, self-sustained vehicle with severely limited space, infrastructure, and broadcast power. Also, planes have sophisticated broadcast and reception needs that massively outweigh the limited threat of a crash.
Not to mention the hassle of collecting this data on the ground, when 99.9999999% of it is going to be irrelevant. So it’s just a cost-benefit situation with high cost and relatively low benefit. Seems to me the time is better spent in improving the functionality and durability of the black box.
The black box automatically sends out a signal, which is easy to triangulate on and uses a lot simpler technology than a GPS. The reason it’s often so hard to find is, as is correctly noted, the floor of the ocean is a big place, not flat, nearly invisible, and divers can’t stay down that long. When a plane crashes on land, the black box is normally found quickly.
I agree with stoli. His (her) reason is right too. Lots of info, and most of it useless, and the stuff you need would be hard to find in all that volume of info. Plus, if the readio breaks, you’re phucked.
What Padeye said. In the same way that in IT, “black box testing” means testing software or hardware from a “dumb” point of view, without understanding the inner workings.