Leslie George Frise FRAeS (2 July 1895 – 26 September 1979) was a British aerospace engineer and aircraft designer; he designed the Type 156 Bristol Beaufighter. He was involved in the development of aircraft and gun-turret hydraulic systems.
In 1915 he started Boulton Paul Aircraft's first aircraft factory at Mousehold Heath, Norwich to make 100 Sopwith Camels. The company was previously a general manufacturing firm that had begun in 1873.
Bristol Aeroplane Company
In August 1915, Frank Barnwell rejoined Bristol Aeroplane Company and was looking for an assistant. He interviewed Leslie Frise and employed him in 1916; Frank Barnwell would become one of Bristol's main aircraft designers until his death on 2 August 1938 in an aviation accident. Barnwell developed the 1916 Bristol F.2 Fighter with Frise's assistance.
He invented the Frise aileron, also known as the slotted aileron, in 1921, which is designed to counteract adverse yaw, which won him the Royal Aeronautical Society's Wakefield Gold Medal (for advances in aviation safety) awarded on 30 May 1933. The Frise aileron has an effect on parasitic drag so that the total drag on both wings is the same when an aircraft executes a roll.