1924 Britain's first government subsidised national airline, Imperial Airways, is formed after four commercial airlines are merged.
1929 Richard Fairey, who formed a company to test aircraft, buys 150 acres at Heathrow from the vicar of Harmondsworth.
Northolt's runway is too short to test bombers and Heathrow is chosen as a new site because of its flatness, lack of nearby buildings, and proximity to the Great West Road.
Fairey manages to placate local residents, who are concerned about the environmental implications of the airfield. The site is known by several names: The Great West Aerodrome, the Fairey Aerodrome, Harmondsworth and Heathrow.