Leslie George Frise was born on 2nd July 1895 in Barton Regis, Gloucestershire, the second son of William George and Alice Cecilia Frise, and was educated at Bristol Grammar School then Bristol University. When Frank Barnwell returned to the British & Colonial Aeroplane Company Ltd. at Filton in August 1915 he sought a technical assistant to work with him on new projects. Barnwell interviewed Frise and persuaded him to resign a commission in the RNAS to join the Company. In September 1915 they laid out the preliminary design of a twin-engined local defence two-seater to a War Office requirement. This, the T.T.A., was not recommended for squadron service, but their next design, initially created as the R.2A two seat reconnaissance machine, developed into one of the company’s most successful products, the F.2B Bristol Fighter. From then on until 1938, it appears that Frise was to specialise in single engine fighters.

In 1921, Frise developed the aileron shape that was to bear his name, developed for its ability to counteract adverse yaw. Although the invention of the Frise aileron, which earned him the 1932 Royal Aeronautical Society Wakefield Gold Medal, was his most well-known, Frise was to have many patents in his name during his tenure at Bristol, including Integral Oil Pump, hydraulic and electric gun turrets.

In 1930, accompanied by H.W Dunn, he visited Nakajima Aircraft Industries in Ota, Japan, who had acquired a licence for production of the Bristol Bulldog fighter. While there, he supervised the construction of the only two which the Japanese works eventually produced.

Frise continued as Barnwell’s technical assistant through the inter-war years, but sadly in August 1939, Frank Barnwell was killed flying an ultra-light aeroplane of his own design and construction. He was succeeded by Leslie Frise, aided by Russell. Under Frise, development of both Blenheim and Beaufort, begun under Barnwell’s leadership, continued, followed by his own design, the highly successful Beaufighter. Later military designs were, however, less successful. The Buckingham, intended as a successor to the Blenheim, saw only limited production, and then only in a support role, while its Torpedo-Bomber cousin, the Brigand, had only a little more success. In 1941 an Air Staff requirement for a long-range, 100-ton, 300mph heavy bomber had led Frise to submit a design for a large, mid-wing monoplane powered by eight Centaurus engines. The request was cancelled but instead the newly formed Brabazon Committee sought from Bristol the design for a post-war, transatlantic civil transport aeroplane - based on the heavy bomber - to carry 90 passengers for 5,000 miles in 17 hours: all with sleeping accommodation. This led, in 1949, to the Brabazon, at the time one of the largest aircraft in the world. Ill-conceived, it was cancelled in 1953.

Hardly had the design begun when, in April 1946, Frise resigned on the grounds of ill health. After two years he was back at work; in November 1948 he joined Hunting Percival Aircraft, Ltd., based at Luton Airport, as Technical Director and Chief Engineer upon the resignation of Arthur Bage. Here he was responsible for the design of the Provost and its successor, the Jet Provost.

In July 1956, Frise resigned from Hunting Percival and in August joined Blackburn and General Aircraft, Ltd. as director of special projects, based in Blackburns new drawing office at Old Brompton Road, South Kensington, where he remained until his retirement.

Leslie George Frise, BSc, FRAeS, AFIAS, died in September 1979 in Avon.