Buoy for DVDR/VCR?

[kuobin]

Every time after a missing over deep water.It will need take a huge effort to recover DVDR/VCR.I wonder if it is feasible to attach a simple buoy to DVDR/VCR,so that they can be found easily.What do you think?

[pattern_is_full]

Well, DVDR and VCR are entertainment devices (DVD Recorder (or DVD-Recordable) and Video Casette Recorder). ;)

If you mean FDR (flight data recorder) and CVR (cockpit voice recorder), that idea has been discussed here every time there is a deep-water accident. There is always a question of cost - but leave that aside for the moment. The other issue is, how do you design such a system to work in 10,000 existing planes, and not cause more problems than it solves?

- where do you put such a device, to be sure it will release successfully, and not be trapped by the wreckage? A crashing plane may hit the water sideways, right-side up, or upside down, so there is no guarantee that putting it in the top, or the bottom, or somewhere else won't just leave it buried in mud and aluminum.

- how do you trigger the device to separate from the aircraft? G-force sensors? Water-immersion sensors? What happens if it gets wet from heavy rain, or a leaky aircraft toilet or sink, or there is some other high-G event (turbulence, mid-air collision). If it triggers accidentally in an otherwise functional aircraft, will it cause an accident (get wrapped around or jam the tail controls, or put a hole in the airplane)?

- if you mount the buoy and FDR/CVR in the skin of the plane, is it more likely to be fatally damaged (and thus useless) than if the recorders are mounted deep in the aircraft structure (where is it hard to let them escape with a buoy).

- suppose two planes collide mid-air - do you end up with two recorders ejected and landing 30 km from the final wreckage, lost in the jungle (or water)?

The operating principle with FDRs/CVRs has been to put them somewhere in the plane where impact damage is least likely (usually near/inside the tail), and then bolt them down so they will hopefully stay with a large piece of the aircraft (30-60 meters of metal is easier to locate that a 0.5-meter box all by itself). And add a sound/radio beacon that can be detected. It doesn't always work - but recorders have been recovered from 1000s of meters of water by doing that.

Bouys for the recorders isn't a bad idea - but it also isn't a good idea, until all such "what-ifs" have been thought about in detail, and given answers.

[stilton]

Not a bad idea but the long term answer has to be ‘live streaming’ of data and Cvr with management/ union agreement this information only be used in the event of a serious incident / accident

[underfire]

Looking at the way some of the boxes come out of a crash, I doubt a buoy would survive very well, not a simple one at least.

Far easier to be streaming data through the IFE system, which is what many aircraft such as the 787, 777, and 350 do now.