The proliferation of performance guidelines and specifications for firefighting foams has created divergent opinions on aviation fire protection standards. In this paper the technical basis for current U.S. and international aviation guidelines is presented. Issues associated with small- and large-scale fire tests are discussed. The correlation between fire test methods in theU.S. Military Specification for aqueous film-forming foam (AFFF) and current aviation fire protection guidelines is established. Trends and areas for further development are outlined.