answer:I suppose technically you don’t own any of the sky above, depending on where the land is located. In cities, you must obtain permits to build structures above the ground, and adhere to local zoning laws on just how high those structures may stand. At a certain height—again, technically the earth’s surface—you are into FAA jurisdiction. Starting at the surface, you would immediately be in either class B, C, D, E, or G airspace (depending on how close you were to an airport, and what size the airport). Depending on how high you went, you might traverse through any number of these classes until you hit 18,000 feet above sea level, where you’d be in Class A airspace. Below the surface, you still might run into problems. Public water, sewage and electrical systems may mean that your land my only extend a few inches.