D was situated one mile from an airport. D enacted an ordinance that prohibited the operation of aircraft below an altitude of 1000 feet above the village. D lies directly under at least one of the civil airways of the airport. It is embraced within the control area as defined by federal laws and regulations. CAB has established instrument approach rules to be followed by aircraft landing at the airport Such rules are mandatory when certain conditions prevail. According to CAB rules, it was necessary for airplanes under normal and safe procedures, to fly over the village at an altitude of 450 and 500 feet. Ps filed this suit to both enjoin D and to void the ordinance as unconstitutional.