The O-3 was designed by Oldershaw as an improved version of the O-2 to complete in the FAI Open Class. As such it had longer and higher aspect ratio wings of 54 ft (16.5 m) span.[1][2]
The O-3 first flew in June 1967.[3] It is constructed of wood, with the nose made from fibreglass. Its wing employs a Wortmann 61-184 airfoil at the wing root, with a Wortmann 60-126 at the wing tip. The wing is equipped with trailing edgedive brakes. The landing gear is a retractable monowheel.[1][2][4]
Both aircraft were constructed as pure gliders and then later motorized with the addition of a twin-cylinder, in-line Yamaha snowmobile engine. The engine is mounted behind the wing spar on a pylon that retracts forward into a bay closed by two doors. The power is transmitted through a belt-drive to a two-bladed propeller. The pylon can be deployed in eight seconds and uses the electric motor from a Ford Thunderbird window winder. The Yamaha powerplant gives a take-off roll of 1,000 ft (305 m) at an elevation of 500 ft (152 m) and produces a climb rate of 350 ft/min (1.8 m/s).[1][2]
The first O-3 was flown by Oldershaw in several US National contests and Oldershaw completed his distance diamond in the aircraft with a flight of 431 mi (694 km).[2]
O-3 serial number 2 was built by Carlton Kibler of Porterville, California and officially registered as a Fry-Kibler O3A Renigade in 1979. In May 2011 the aircraft was still on the FAA registry.[2][7]
