Carbon fiber or some mystery metal, but a good solid blow to any operating system sans the blade and it would probably break it. Wife and I had this discussion after watching the news. Fox - Harris Faulkner made a good point, if it’s gas powered it’s gotta land at some point, and if it’s the size of an SUV it’s not gonna stay airborne forever with a battery. Even a Prius battery pack is pretty damn heavy just to get it outta the driveway - way too heavy to fly and limited range before needing charging.