COMPOSITE FLIGHT SERVICE EVALUATION PROGRAM FOR HELICOPTERS.

Progress of NASA and U. S. Army Research and Technology Laboratories sponsored programs to evaluate composite structural components in flight service on commercial and military helicopters is described. Four composite components - the vertical fin, forward fairing, baggage door, and litter door - are to be installed on Bell 206L helicopters operating in widely different climatic areas. Concurrent with the flight evaluation, test specimens with be exposed on ground racks in each area. Helicopter components and ground exposure specimens will be withdrawn and evaluated at five intervals during 10 years of service and environmental exposure. Composite tail assemblied - including the tail boom, horizontal stabilizer, and vertical fin - will be installed on Bell OH-58 helicopters operating at four U. S. Army bases having distinct climatic conditions for evaluation over a period of 2 years. The status of these programs is reviewed, including results of design and certification/qualification activities and the flight service evaluation plans.