In reply to:

This always raises the question, why don't they just make the entire plane a black box so it survives a disaster?



Too expensive. Airlines are there to make money. Many aren't making much now. If all the strongest and latest in advanced materials, electronics, and construction techniques were used, planes would be far too expensive to fly both from a fuel economy standpoint as well as cost of ownership. So safety in planes is a trade-off. The same could be said for cars. They could all be built like tanks, but not many of us would be able to afford them. There is an economics article that I believe was called something like "Airline Safety- How safe is too safe?" that covers all this in great detail.

Stu
_________________________
If you want it to break, buy Sony!