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The faculty and staff of the Raspet Flight Research Laboratory (RFRL) have concluded a project with an industrial customer to lead a group of engineers and technicians in a study of the “art” of developing a prototype composite aircraft. The objective was to produce a turbine powered, composite, pressurized, single-engine aircraft, which would introduce the team to the many aspects of a complex aircraft in a environment. The prototype Allison Soloy turbine conversion of the Beechcraft A-36 was chosen as the study aircraft. It was proposed that the A-36 structure be replaced with composite structures in three steps of increasing complexity. The sequence was to first design-build-test-fly the tail, then the wings, and finally the fuselage. To limit the difficulty of the project development and to allow a meaningful comparison between aluminum and composite structures, the configuration modifications were to be minor and to utilize existing RFRL Marvel II composite technology.

A detailed description is presented of the design and fabrication of the Marvel II composite wing. The wing was constructed in a short time using a combination of sailplane and modern prepreg composite structures technologies. The wing design requirements were to minimize the use of metal in the structure, to develop a high performance flap system which would be insensitive to a sand environment, and to explore composite production structural concepts. The desired high lift capability was achieved through the use of a double slotted flap with a fixed slat. A unique flap support mechanism was developed to give excellent flap positioning over the flap angle range. The wing was constructed in three major assemblies, the spars, the wing skins, and the flap and ailerons. The wing spar was constructed applying conventional sailplane techniques which uses a wet layup of S-glass rovings. The fabrication of the wing skins was made in three steps.