There are algorithmic solutions to maintaining some semblance of flight with a damaged quad copter, even down to one remaining prop, however it involves spinnin

There are algorithmic solutions to maintaining some semblance of flight with a damaged quad copter, even down to one remaining prop, however it involves spinning the entire air-frame to stay aloft -- which means it is probably not suitable for a human passenger drone https://newatlas.com/quadcopter-failure-algorithm/30031/ https://newatlas.com/quadcopter-failure-algorithm/30031/