Leslie Frise

[1] Early in First World War he served in the Royal Naval Air Service (RNAS).

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.

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.

In 1934 he developed, with Frank Barnwell, the Bristol Type 143, a monoplane with retractable undercarriage; only one prototype was made.

He worked for 32 years for Bristol retiring, as chief engineer, in 1946 on grounds of ill health.