In a recent podcast by Adam Savage[1], an avid drone enthusiast, drones are described as "cinder blocks with propellers attached" or something to that effect.

In a recent podcast by Adam Savage[1], an avid drone enthusiast, drones are described as "cinder blocks with propellers attached" or something to that effect. In one incident described in the podcast, Will describes a multiple-redundant multirotor losing a single propeller and having the vibrations of that cause a cascading failure of the other propellers, ultimately bringing the machine down in an uncontrolled manner. I think that as a blanket rule it is very appropriate to not allow amateur UAS to fly directly overhead of people not aware that it is there. If a machine should be built that is provably safe against such failures or demonstrates an extreme tolerance to them, then special licensing could be dispensed. [1] https://www.youtube.com/watch?v=0RvHI79CyqQ https://www.youtube.com/watch?v=0RvHI79CyqQ