Is there a point you can fly before it’s considered airspace? Say if your on private property and don’t go above 50’ I know the rules say it’s a 400’ ceiling and not to fly at night! But say I wanted to make a movie and everyone was a participant could I fly at night if I kept It at say 10’-20’ above everyone? I’m not planning this just inquiring where airspace starts? Like my house in Pennsylvania I don’t own the mineral rights so I only own the ground down to a certain depth then it belongs to someone else that can do whatever they want for mining etc! Is the airspace similar? Obviously a manned aircraft shouldn’t be 50’ above the ground unless it’s landing or taking off!