the North Atlantic route and remains in operation. The first women pilots were not licensed in Canada until 1928. As more men were sent off to direct combat roles, women were increasingly employed in aviation technical support roles and in aircraft manufacturing. Ferry Command and the British Air Transport Auxiliary used Canadian female pilots for trans-Atlantic movement of fighters and bombers. In the West, the North West Staging Route was a channel for warplanes to be sent from factories in the United States to the Soviet Union. Starting in 1940, fifteen air bases and multiple emergency landing strips were prepared stretching from Great Falls, Montana through Western Canada to Alaska. The aircraft were completed in Soviet markings, winterized, and flown by stages to Alaska. There, Soviet crews would take over the aircraft and carry on through Siberia to operational areas. About 5000 fighters and 1300 bombers and transports were ferried to the Soviet Union over this route. Additionally, seven hundred aircraft were sent for air defense of Alaska against a threat from Japan, and many internal communication, supply, and search-and-rescue flights used the air route as well. Civil aviation during the war was restricted, with priority given to travel for war business, and rationing of oil and gasoline. However, Northern bush plane operations in support of mining carried on, with such tasks as the export of uranium concentrate for the atomic bomb project. Aircraft manufacturing The Curtiss company established a branch plant for manufacture of engines and airframes in 1915; this was taken over by the federal government and operated as Victory Aircraft until 1945, when it was sold to Hawker Siddeley. Many aircraft made in Canada during the Second World War were licensed designs from British or American manufacturers, in some cases altered for available materials, engines, and production facilities. During the Second World War, companies such as Canadian Car and Foundry, not ordinarily in the aviation field, turned their production lines to the manufacture of fighters and bombers. About 16,000 aircraft were manufactured in Canada, including about 450 four-engine Avro Lancaster bombers and 1400 Hawker Hurricane fighters, as well as many training aircraft such as the Harvard, Anson, and Tiger Moth. Aviation manufacturers in Canada included: Canadian Vickers 1923-1944 Fairchild Aircraft Ltd. 1920-1950 Fleet Aircraft 1928-1957 Canadair 1944-1986 Bristol Aerospace 1930-1996 founded as McDonald Brothers Avro Canada 1945-1962 de Havilland Canada 1928-1986 Viking Air - 1970–present Bombardier Aerospace