Several FARs reference Congested Areas without giving a clear definition of what constitutes "congested".
- §91.119 states that over any congested area of a city, town, or settlement, or over any open air assembly of persons, airplanes must maintain a minimum safe altitude of 1,000 feet above the highest obstacle within a horizontal radius of 2,000 feet of the aircraft.
- §91.303 Disallows aerobatic flight over any congested area of a city, town, or settlement;
Volume 6, Issue 7 of AOPA ePilot (February 13, 2004) addresses the question of what qualifies as a congested area per §91.119:
- When there is no specific definition of a term used in the regulations, its meaning is clarified through NTSB case law and FAA chief counsel opinions. Although it is typically understood as an area of a city, town, or settlement, you'll probably be surprised to learn that the Civil Aeronautics Board (now known as the NTSB) has also considered these areas to be congested: 10 houses and a school; a university campus; a beach along a highway; a camp with people on the dock and children on the shore. If you are not sure, treat the area as if it were congested. And remember, the requirement of the regulation is not only to remain 1,000 above the ground, but also to clear towers and obstacles by 1,000 feet vertically or 2,000 feet horizontally.