Regardless of how much land you own, you don't own the airspace above it. Although a "hard value" has never been established a Supreme Court ruling back in 1946 or so, which is the latest case to determine airspace ownership, put private airspace ownership at a height the property owner can effectively use. For the purposes of that particular case that height was about 86' AGL. For all intents and purposes, the tallest object on your property is the maximum extent of your private airspace ownership.
The FAR's do place altitude limits on most manned aviation activities based on population congestion, with some exceptions for helicopter operations. In low congestion areas the altitude floor is 500'. For congested areas it's 1,000'. However, in areas sparsely occupied by humans manned aviation can fly as low as they want, as long as they can make a safe landing in the event a power unit fails. So if your property is out in the middle of the boondocks with nobody but you and your structures around they can fly pretty darn low as long as they don't touch the ground and remain at least 500' separation from you and your buildings. Your cows, horses, or sheep aren't covered by that as the regs specifically reference persons or structures but if the flight activities caused you to suffer a loss of livestock or business revenue you might recover those losses in a civil court.
Where collision avoidance between drones and manned aircraft is concerned, the FAA places the onus of "see and avoid", "safe separation of aircraft" 100% on drone operators. Full scale is not responsible for seeing and avoiding drones. They are responsible for assuring the safe outcome of a flight but not for seeing and avoiding drones. So in the U.S. ANY collision between a manned aircraft and a drone, regardless of location or altitude, will be the fault of the drone operator. About the only way to reduce our liability in this regard would be to have a NOTAM generated and published that describes our location, altitudes, and times of flight to provide full scale operators a means of determining where drone operations are being conducted in order to avoid them. Such is likely mentioned in RPR’s mitigation factors for his waiver. Even then, we are responsible for providing a means to maintain a watch of the airspace for manned aircraft and takes the steps necessary to assure safe aircraft separation.
I'll try to answer your original question, which was a very good one, in another post.
) when it is at or below 400 feet?
