Why may aircraft normally fly over private property without the landowner’s permission?

While the ancient legal maxim Cujus est solum ejus est usque ad coelum et ad inferos suggests that a landowner owns the space above their property, modern air law has moved away from a literal interpretation of this principle.

In most jurisdictions, the right of a landowner to the airspace above their property is limited to the height necessary for the reasonable enjoyment of the land. Consequently, by the 1920s, it became established through legislation and judicial decisions that aircraft are permitted to fly over private property without the owner's permission, provided the flight is conducted in accordance with aeronautical regulations.

This immunity is restricted to the mere passage of the aircraft. It does not protect operators from liability for damage caused to the property or for other encroachments that interfere with the use or enjoyment of the land, such as excessively low flights, noise, or vibration.12