The joined wing is a new type of aircraft configuration which employs tandem wings arranged to form diamond shapes in both plan and front views. Wind tunnel tests and finite-element structural analyses show that the joined wing provides the following advantages over a comparable conventional wing: lighter weight and higher stiffness, less induced drag, lower wave drag, higher trimmed maximum lift coefficient, plus built-in direct lift and sideforce capability. The Phase I work addresses the feasibility of testing a manned, low-cost, joined wing research aircraft of approximately 32 ft. span to be constructed during Phase 11 and tested in flight and in NASA wind tunnels. Several candidate vehicles are studied, including one employing a fuselage identical to that of the AD- I oblique wing research aircraft.
