Gloster Guan

The Gloster Guan was a single-engined, single-seat experimental biplane fighter built in the United Kingdom to test how supercharged engines performed at high altitude. Three were ordered by the Air Ministry in 1925, though only two were built. They used Napier Lion engines with an exhaust-driven supercharger, now called a turbocharger, mounted under the propeller, and an all-metal fuselage with the thick upper wing and thin lower wing of Folland fighters. The first went to RAE Farnborough in August 1926. It reached 175 mph at 15,000 ft and a 31,000 ft ceiling, but the fast-spinning turbo-superchargers were troublesome and the programme and third aircraft were cancelled.