Gloster Grouse

The Gloster Grouse was a small British biplane of the 1920s built to test an idea of designer Henry Folland, who paired a thick, high-lift upper wing with a smaller, thinner lower wing to get high lift at take-off with low drag. It was made by fitting new wings to a modified Gloster Sparrowhawk fuselage and kept the Bentley BR2 rotary engine of the Sparrowhawk. The Grouse first flew in 1923 and proved the layout, which led directly to the Grebe and Gamecock fighters. Rebuilt in 1924 as the two-seat Grouse II with an Armstrong Siddeley Lynx radial, it failed to win RAF trainer orders against the Avro 504N and was sold to Sweden.