(I'm anticipating the SLF - what do you know about it comments but hey)
The technology may be available to do wonderful things with data trasmission which may be extremely useful. There is no doubt about that. There are concerns about security/bandwidth accessibility/signal conflict etc and all are valid, but a black box tells you what has happened. It is a totally retrospective instrument.
Bandwidth, etc does not come cheap and in pure cost terms alone may I suggest that the cost of developing an all singing all dancing black box may be offset by investing in technology which may prevent an accident in the first place?