The Mathews PUP (Perfect Ultralight Plane), also called the P.U.P., is an American ultralight aircraft that was designed by Lyle Mathews in 1983 and made available in the form of plans for amateur construction.
[1][2] The aircraft was designed to comply with the US FAR 103 Ultralight Vehicles rules, including the category's maximum empty weight of 254 lb (115 kg).
It features a biplane wing arrangement, a single-seat, open cockpit, conventional landing gear and a single engine in tractor configuration.
Its 32 ft (9.8 m) span, unstaggered wings employ both interplane struts and cable bracing.
The fuselage consists of a single aluminum rectangular 2x3 inch (5 X 8 cm) tube.