Preservation of Useable Open Space

Usable open space is open and unobstructed land that could be used for forced landings by aircraft in emergencies. It must be relatively flat and free of significant obstructions, such as walls, large trees, buildings, and overhead wires. Streets and adjacent front yards, and parking lots shall be considered usable open space provided that they meet the minimum lot size and configuration requirements. The minimum size and configuration of usable open space shall not be less than 300 feet by 75 feet.

The reason for this requirement is that the risks to people on board aircraft and damage to property can best be minimized by providing as much open land area as possible within the airport vicinity. A large majority of aircraft accidents occurring away from an airport runway are controlled emergency landings in which the pilot has reasonable opportunity to select the landing site.

Clustering of development and providing contiguous yard and parking areas is encouraged as a means of maximizing open land and providing continuity of open land areas between developments.

In order to establish the open land areas available within a proposed development, building envelopes and the airport safety zones should be indicated on development plans. The required minimum amount of usable open space area shall be provided on the proposed development site, unless satisfactory usable open space area(s) can be provided within or adjacent to the safety zone in which the development is located.