Re:Flying Taxis May Be Years Away, but the Groundwork Is Acc...
by ShorsHammer on Saturday March 03, 2018 @11:45PM
(#16513307)
Autorotation is an immutable property of variable pitch rotors. Whether it can land properly without hurting a person is a physics/biology problem
3rd answer down :)
https://aviation.stackexchange.com/questions/37360/can-a-pas...
The only practical option is independent dual redundant power systems so that one failure can't take out more than half the propellers. Plus a rocket assisted ballistic recovery parachute to allow a (mostly) survivable crash landing in case of a catastrophic failure. Of course there will still be some rare failure modes where a parachute won't be sufficient.