Nick,
I take your point entirely about the relative merits of other systems and welcome the efforts by Honeywell and Sikorsky, along with Eurocopter and the HTT concept, to develop these technologies.
What annoys me about the exposure time concept is its migration to the onshore environment (not yet but manufactures are pushing for it). I am not so concerned about the offshore environment because I think the deck edge exposure is genuinely very small and we all stand a fighting chance of getting away with it.
However, when confronted by large, hard obstacles with no escape route, during a take off, and the regulator/manufacturer is saying "oh they're within the exposure period" I'm less happy. Ditching or soft ground is one thing, hitting trees or buildings is another thing entirely. The passengers will not be aware of this fact!
I do understand your point Nick, though the airline accident rate is also predominently CFIT induced. The test would be would we be happy sending our kids on holiday every year in an airliner that may or may not climb away after take off if an engine fails? If not, then why would we expect the kids father and his passengers to do it daily?
Thanks Jim for the informed detail on JAA thinking.