Constructed of welded steel tubing with aluminum skinning, the Sidewinder has all-aluminum wings and is stressed to ±9g ultimate loading to allow aerobatics. Engines can be fitted with power ratings from 90 to 180 hp (67 to 134 kW) (some say 65-125hp), weighing up to 310 lb (141 kg), enclosed in a fibreglass cowling. A sliding canopy covers the cockpit, the landing gear uses some landing gear components from the Wittman Tailwind and conventional controls are fitted but with an all-flying tailplane for pitch control. An unusual under-fuselage spoiler is used for approach control. The original design shared the same windscreen as a Thorp T-18. The prototype attended the 1969 Experimental Aircraft Association convention at Rockford, Illinois, winning the Outstanding Design Award.