This is a big, big worry of mine. I'm considering doing commercial work with drones, and the major thing holding me back is the risk of injuring others with these things. The DJI Phantom, and Inspire, could kill someone if they fell from high enough. And I can tell you from personal experience, the software is simply not even CLOSE to bug-free enough for me to be worry free.
The more I think about it, the more I think, the risk of flying these things in populated places just isn't worth it.
I wonder if a heavier-than-air airship design would be safer. A balloon with helium or even hydrogen would let such a device fall slowly with engines off, and motors would let it fly up and maneuver around swiftly enough.
Why, it can still be multi-rotor, and even capable of bigger payload with the same battery.
The air drag from the balloon will be an issue. OTOH the motors could be run at low power when cruising and at high power when speedy maneuvers are required.
The size will definitely be bigger. But if we talk about professional-grade drones (for video reporting, etc), they are large and expensive as they are. Improved safety and thus easier time getting allowed in to a worthy event might be more important than a lean package.
Could the airship configuration be a recovery mechanism? IE, instead of having a parachute or airbag to soften the landing, have compressed helium release into an airship and then continue powered flight with whichever motors remain?
The more I think about it, the more I think, the risk of flying these things in populated places just isn't worth it.