In March 1967 Palmer built and flew the first true weight-shift powered ultralight trike aircraft: the Paraplane (FAA Registered N7144) and it was controlled by a single vertical control bar. The Paraplane used two West Bend-Chrysler 820 engines (8 hp at 6000 rpm, reduced to 4700 rpm for about 6.5 hp (4.8 kW) each, for a total of 13 hp). Each engine had a direct drive to a 27in diameter two-blade propeller made of polyester & fiberglass. On March 24, 1967 Palmer registered the trike at the American FAA as the Palmer Parawing D-6, serial 1A, N7144; No restrictions were noted.