Recent discuss of people being injured by airbags got me thing about how else they could be deployed and I was struck by the idea of using them for escape.
If a crash could be detected in sufficient time to allow a hot air balloon to rapidly inflated, the whole vehicle or perhaps just a passenger or two could float away ...
The traditional explosive charge could start the inflation of such an air bag, possibly freeing it from a housing on the roof at the same time. Then it would be a matter of pumping enough hot air or appropriate gases into the bag as fast as possible allowing for the rising effect to start.
Rising even a small degree could allow for the vehicle to knocked away in response to a crash, albeit possibly into other non-floating cars.
Accidental triggering could actually be quite beautiful as suddenly a car would be seen to take to the air for no apparent reason ....-- Aristotle, Mar 28 2009 Ford uses Car-Sized Ballons http://www.ridelust...or-safety-research/A different use for hot air and crash testing. Found during my "prior art" Google search. [Aristotle, Mar 28 2009] Pimp my dirigible. http://pro.corbis.c...3F4-FC54861BA349%7D [2 fries shy of a happy meal, Mar 28 2009] Description of Fast Ascent Ballooning Accident http://today.msnbc.msn.com/id/20461189/Account of ballooning accident that caused a rapid ascent, possibly due to a fire in the basket. [Aristotle, Mar 30 2009] //detected in sufficient time// ten, fifteen minutes in advance, for instance?-- loonquawl, Mar 28 2009 This is indeed, possibly, a minor draw-back but there must be a way to vent shedloads of hot gasses in very short frame. Possibly they are too dangerous or expensive to be used in commercial hot air balloon flight but they might be viable in a safety critical application.
Once the bugs have been ironed out with crash test dummies ...-- Aristotle, Mar 29 2009 You say lift the tires a bit off the ground so the car can get "knocked away". Wouldn't this be the opposite effect of what you want? Knocked away quicker=higher acceleration=more pain. What you want is a system that increases your car's mass right before a collision. Or maybe some type of inertial dampener. That would be about as feasible :)-- DIYMatt, Mar 30 2009 Even with the infamous vacuum-balloons, you would not get more than 1.3kg lift per m³ - Meaning to only lift the driver (65kg), your explosive charge would have to create a balloon 50m³ big. This would make the driver float, but not rise. To rise with 1g acceleration, -> 100m³; This still needs a crystal ball somewhere in the crash detector. To rise even faster -> bigger balloon, but bigger balloon = higher drag, so there is some ceiling to what you can do. Maybe something more akin to a rocket seat?-- loonquawl, Mar 30 2009 //What you want is a system that increases your car's mass right before a collision//Some kind of light-speed drive then?-- coprocephalous, Mar 30 2009 One of the problems with this, that I foresaw, was that detaching the driver could be disastrous because a partially detached driver even could be decapitated due to differences that would develop in the frame of reference between the driver and the car.
Unfortunately this does sound like it would do more to save the car than the driver, even if I could get it to trigger fast enough, because the car is better suited to survive the change in acceleration.
However I'm still curious about how fast you could build up the effective lifting power in a balloon that been prepared with an airbag explosive charge. I suspect that dumping liquid oxygen on some sort of combustion might be best bet and a search revealed an account of a fatal accident due to a fire in the basket (see link) that ascended faster than expected.-- Aristotle, Mar 30 2009 random, halfbakery