Circa 1975 Fred W Wallman Jr built the two-place, open cockpit, high-wing monoplane, Sportplane, registered N4FW. The fuselage and tail were steel tube, and wing was all wood.
The Sorrtplans was first flown on 24 September 1975, piloted by Bert Sissler. Only the one was ever built.
Engine: 115hp Lycoming O-235-C1
Useful load: 566 lb
Cruise speed: 100 mph
Stall: 35 mph