Several comments are worried about gliding on power failure on these craft. A couple observations. Commercial airliners like Airbus with electrically actuated

Several comments are worried about gliding on power failure on these craft. A couple observations. Commercial airliners like Airbus with electrically actuated control surfaces have redundant power buses, crossbars, actuators etc. A multirotor doesn't actually need full power to emergency land, just enough o hold a descent rate of 10-20 kts like a parachute. If run all your motors at less than full power normally, then if you lose a few, you have some capacity to throttle up the remainder in concert to emergency land. I'd be more concerned about how it selects an emergency landing spot over a city.