The aircraft was designed to comply with the US FAR 103 Ultralight Vehicles rules, including the category's maximum empty weight of 2540NaN0. The aircraft has a standard empty weight of 2480NaN0. It features a strut-braced high wing, a single-seat, conventional landing gear and a single engine in tractor configuration.
The aircraft is made from bolted-together aluminum tubing, covered in Dacron sailcloth. Its 30.51NaN1 span wing is supported by "V" struts and jury struts. A single aluminum tube acts as the fuselage keel and supports the tail at the aft end, the wings in the middle and the engine at the front. The engines supplied include the 280NaN0 Rotax 277 and the 350NaN0 Cuyuna UL II. The aircraft may be flown with an open cockpit or with zippered sailcloth cockpit enclosure panels installed for cold weather flying. The controls are conventional three-axis and include a center stick, adjustable rudder pedals and full-span ailerons. The landing gear has aluminum torsion suspension on all wheels and the tailwheel is steerable.
The aircraft was introduced just as the ultralight market in the US became saturated and demand collapsed. As a result, even though the Sundowner had many innovative features, it was not a commercial success.