COMPOSITES QUALIFICATION CRITERIA

The use of composites by the rotorcraft industry, in fatigue-critical applications, has been accepted as an advancement in the state of the art. The original applications of composite primary structure were treated with caution by both the manufacturers and the certifying agencies due to the lack of service experience. The initial concerns over the long-term performance of composite structures have been largely resolved by the excellent field history, in numerous applications, of a wide variety of composites in service, and the many advancements in the design, manufacturing, and test processes that have occurred in that period. This paper presents realistic and practical qualification criteria which take advantage of the large body of data available from field experience, research programs, design efforts, and test programs on composite structure. It is recommended that the certifying agencies consider the application of these criteria in future programs.