De Havilland Propellers
De Havilland Propellers of Hatfield and Bolton, part of De Havilland.
De Havilland Propellers was established in 1935, as a division of the de Havilland Aircraft company when the company acquired a license from the Hamilton Standard company of America for the manufacture of variable-pitch propellers at a cost of about £20,000. Licence negotiations were completed in June 1934.
1935 Geoffrey de Havilland patented "improvements in or relating to aircraft and propulsion means therefor" which provided a means of powering the variation in pitch of the propeller to optimise engine power at take off and whilst cruising, thereby addressing the problem of such propellers so that the rotational speed could be varied between landing and normal flight. This was (presumably) incorporated in the propellers made under the Hamilton licence, something that proved to be of great importance in powering the aircraft later fighting in the Battle of Britain.
Pre-WWII A production plant was built at Lostock, near Bolton in Lancashire in only nine months as part of the government's emergency pre-war shadow-factory programme.
By 1945 the de Havilland Aircraft company had gained around 20 patents for its own developments in connection with variable-pitch propellers.
De Havilland Propellers, Ltd. was incorporated on April 27, 1946, with the main headquarters at Hatfield as the centre of design, development and flight-testing, and with the main production plant at Lostock, near Bolton in Lancashire.
Late 1940s - early 1950s: Work on missiles began at the Hatfield plant in facilities which had been used during the war for development and testing of aircraft propellers.
c.1960 the company became Hawker Siddeley Dynamics which in turn became British Aerospace Dynamics, later BAe Systems (Guided Weapons Division) until closure of the site in 1990.