“3. Your spine will not survive a 15 foot vertical drop onto a runway if you land in a seated position.”
Most of the people in the Minnesota bridge collapse survived the drop from 60 ft. Any comments?
I’ll have to say it must’ve been a tempered fall. Not free. And also, cars are much better handled to survive it than the completely flimsy construction of the plane interiors. Those seats will come off and crush everyone very easily.
The bridge fell from one end,
the structure fell into water,
the vehicles have squishy tires,
they have springs in the suspensions,
the seats have more padding,
most had a steering wheel to hold onto...
And they hit what? Water? The bridge trusses also undoubtedly absorbed considerable shock as they collapsed and unless the bridge hit perfectly flat with the water the gradual shock as the collision spread across the span would also absorb shock. Remember the comedian Red Skelton? One of his gags was to fall down, but despite the fact that he was 60+ years old, he never hurt himself. The reason was that he bent his body into the fall, so he "rolled" onto the ground, rather than hitting it flat, as he appeared to do. That's almost certianly how the bridge hit, first on one end or side, spreading the collision in time and dramatically reducing the shock.
The G load experienced is highly dependent on how much cushion exists. I don't know current aircraft certification standards, but I seem to remember that an aircraft I owned, certified under the old system was only tested at a 13 foot drop, and that was with tires and existing shock absorbers in place. Work the numbers for the rate of descent of an aircraft, and that is about the limit that an aircraft can withstand without breaking something. A fuselage hitting the ground would be even worse because it has no shock absorption.
Here's an experiment. Get up on your kitchen table and jump off onto a solid concrete floor (no carpet), with bare feet held flat with the ground, while holding your legs rigidly straight. That's maybe only 3 feet.
I take no responsibility for anything broken.