It would seem that, at airplane speeds, mass would be the primary concern. While the first thing you hit on a drone is its cheap plastic propellers and superstr

It would seem that, at airplane speeds, mass would be the primary concern. While the first thing you hit on a drone is its cheap plastic propellers and superstructure, at its core is a dense battery, which can be fairly heavy on the common DJI phantom drones (DJI 3 weighs 1280 g (=45 oz. ) with battery.) For comparison, a common pigeon (is that the bird that gets hit?) weighs ~9-13 oz. Having said that, I don't know if these are the drones that pilots are spotting. They're the most common enthusiast drone (~$500-$1k), though I'm sure they're outnumbered by the junk toy variety.