Bountyhunter;

I don't have any stats but I believe the vast majority of fatal small aircraft accidents have nothing to do with an engine failure per se. Most of them are either weather-related or pilot error, or a combination of both. Even in the cases I've read of where engine failure has directly caused a fatal crash, the fatality has resulted from the pilot's failure to handle the situation correctly (e.g. the pilots who lose an engine during climbout and try to turn back to the airport, get too slow, and thunder in vertically from 300 feet).

The slower speed and shorter landing roll of the STOL aircraft may be an advantage on landing, but it might have to be weighed against other factors, such as the additional complexity of the aircraft in a critical situation. (Read what Cody Lundin has to say about the difference between gross and fine motor skills in a survival situation, for example.)

As for adding inflatable bags to the aircraft, read the articles on this site about the survival rate of pilots when ditching the aircraft. You're trying to come up with a solution to a problem that, effectively, doesn't exist. to do so, you would be adding not only to the complexity of the aircraft (what happens if one of these bags accidentally inflates, for example?) and the cost (flying is expensive enough as it is, thank you) but the weight of the aircraft.

The last may not seem important to a non-pilot, but consider that an aircraft has a maximum take-off weight. If you add one pound to the empty weight, that's one pound less fuel you can carry. If pilots can't carry as much fuel, they will have to stop for fuel more frequently; that means more takeoffs and landings. Consider, then, that most aircraft accidents happen during the takeoff and landing phases; is the increase in accidents caused by the additional takeoffs and landings going to outweigh the tiny percentage of deaths caused by people who lose an engine overwater, ditch the plane, and then can't get out in time? (Most light planes will float for a considerable length of time on their own, anyway.)

(Read what Laurence Gonzales has to say about trying to increase safety by adding complexity.)

These are my opinions only, and not terribly well informed ones at that. <img src="/images/graemlins/laugh.gif" alt="" />