The AEREON 26 was an experimental aircraft developed to investigate lifting body design with a view to using its shape to create hybrid designs, part airship, part conventional aircraft. It was powered by a piston engine, driving a pusher propeller, and generated lift through the aerodynamics of its lozenge-shaped fuselage. Although results of flight tests conducted in 1971 were promising, funding for larger and semi-buoyant aircraft was not forthcoming at the time. The story of the test program was recounted by John McPhee in his book The Deltoid Pumpkin Seed (). This aircraft has a special place in UFO and conspiracy lore, since enthusiasts have drawn parallels between the shape of this aircraft and some reported UFOs from around the same era. Background The AEREON Corporation, established in 1959, at first concentrated on the construction of a prototype three-hull hybrid airship, the AEREON III. Completed in 1965, the prototype was lost during taxiing tests the following year, without having flown. Following the destruction of the AEREON III, the firm sought "a new and better solution." AEREON's Monroe Drew and John Fitzpatrick employed German physicist Jürgen Bock, formerly of the Max Planck Institute for Nuclear Physics, Heidelberg, Germany, and the U.S. Army's Aberdeen Proving Ground, to develop a list of parameters that would be fed into a computer at the General Electric Space Center, Valley Forge, Pennsylvania, in order to determine "the optimum configuration for enclosing maximum volume without too much penalty of drag." AEREON 26'''s deltoid configuration, "a shrewd and practical compromise between an airfoil and a sphere," was the result of these efforts. Rubber-powered and gasoline-engined models of the configuration were flown and wind tunnel tests conducted before testing of the 26 itself began. Description Structure and form According to a paper delivered to the Interagency Workshop on Lighter than Air Vehicles in 1974 by AEREON president William Miller, the 26's shape—dubbed an "aerobody"—was "a lifting-body [sic] of deltoid planform, elliptical cross-sections, and a fineness ratio of 4:5." Among the advantages claimed for this hull form were proximity of the aerodynamic center, center of buoyancy, and center of gravity and a minimal need for trim-control devices, thus facilitating the transportation of "a full range of tonnages at various speeds without major trim requirements." In McPhee's words, the craft was "a triangle with a deep belly and a vaulting back" or a "delta" when seen from above and a "fat