|Abstract:||Widely distributed throughout the United Kingdom, Class A airfields have significant potential as open-ended spatial heritage. Given their geometric abstraction and physical patterns, the airfields could be interpreted in unexpected ways in the distant future, as their original technology and purpose become less well understood. To preserve and allow for the potential of such interpretation, the conservation of Class A airfields should focus on general landscape characteristics—with emphasis on scale, patterns, and spatial relationships—rather than original functions and material conditions. Also, alternative uses or development should be allowed on a limited basis. To help guide preservation efforts, a "toolkit" of scenario-based categories and a grading system is developed and described. Principles of preservation guidance for contemporary development are outlined through selected case studies, although the vision of Class A airfields as open-ended heritage is based on one of the distant future. This exploration of Class A airfields as open-ended spatial heritage is offered as a sort of proposal to Historic England, a government heritage agency, to develop guidelines for preserving historic airport landscapes. It also casts new light on the topic of airport landscape.