With respect Xenia & Iguanahead, I have a pretty good understanding of risk analysis and statistics, and I have spent quite some time reading up on this topic. I also have spent quite a lot of time reviewing NTSB & CAA accident reports, and databases such as that maintained over at
http://www.airdisaster.com
My apologies for any offence caused, which was certainly unintentional. However, most of the response in this forum seems to be driven by emotion rather than logic.
It is clear, for example, that more lives would be saved by fitting aircraft with smoke hoods than with lifejackets (clearly most would be saved by fitting both). However. the airlines have repeatedly refused to fit them on the grounds of cost.
It is also clear that significant numbers of lives would be saved by having all the seats backwards-facing. This is rejected on grounds of cost and customer acceptability (though personally I am perfectly happy in the BA J-class).
In any environment you have to decide how much you are prepared to spend to save a life... this calculation is done for road safety, building fire regulations, etc. etc. Broadly, once the "price" is set in any particular environment then safety features which cost less than that amount per life saved are implemented and those which cost more are not.
In airlines it seems to me that in fact the lifejackets are a bit of an anachronism. They exist primarily for historical reasons (flying boats etc) because if today you built the regulations from scratch you would start (I think - I will need more time to get the detailed statistics) with backwards seating (which has more or less zero net cost if you are starting from scratch), then smoke-hoods, then, maybe, lifejackets (obviously there could be various other things in the list too).
As for the role of the cabin crew, I think I have a reasonable idea - I have spent a good proportion of the last 3 years in their company (my apologies if you're one of the CX crew that I have bored to death in the middle of the night on the LHR, SFO, LAX or CDG runs).
If the airlines' over-riding consideration in selecting cabin crew was to maximise the number of survivors in a crash-landing then the criteria for selection would be quite different, and more like those for firefighters (ability to carry an unconcious 200-pound body up the aisle and out of the exit whilst wearing a smoke-hood for example). In real life, it is a balance between providing the best service in the 99.99whatever% of cases where there are no problems and being most effective in a crash. The airlines know that very, very few passengers have "effectiveness of the cabin crew in a crash" at the top of their list of priorities when choosing an airline, and they choose their cabin crew accordingly.
Moreover, survivability of crashes doesn't seem to vary much by airline, but the rate of crashes does (Korean and China Airlines, for example, are above my acceptable threshold level). Having said that it is clear that there is much more chance of a, say, BA cabin crew being able to drag my unconcious 6'3", 250-pound body down the aisle than there is of a CX stewardess. There are reports on the SQ006 at Taipei which give mixed reviews at best to the effectiveness of the cabin-crew there, and I understand that at least one change was made in SQ's uniform/procedures to make the footwear more practical.
So, in summary, all I am saying that all these safety issues are a trade-off and that in an ideal world I would make the trade-offs slightly differently. No disrepect intended to any cabin crew, who generally do a pretty good job.