The Short S.16 Scion and Scion II were 1930s British two-engine, cantilever monoplanes built by Short Brothers and by Pobjoy Airmotors and Aircraft Ltd. in Rochester, Kent between 1933 and 1937. Altogether 22 Scion/Scion II aircraft were built and they provided useful service to operators working from small airstrips/water courses in many parts of the globe, including Europe, the Near and Middle East, Sierra Leone, Papua New Guinea and Australia. Many were impressed into the Royal Air Force during the Second World War, providing pilot ferry services, anti-aircraft co-operation and radar calibration duties. Of the civilian Scions, at least two were still operating in Australia in 1966, one having been re-engined with de Havilland Gipsy Minor engines.

The Pobjoy Niagara is a British seven-cylinder, air-cooled, radial, aero-engine first produced in 1934. The design ran at higher speeds than conventional engines, and used reduction gearing to lower the speed of the propeller. This led to a noticeable off-centre mounting for the propeller. The Niagara was a popular engine for light and experimental aircraft, well regarded due to its small diameter, smooth operation, low noise and innovative engineering.