The Cessna L-19/O-1 Bird Dog is an observation, liaison and training aircraft. It was created by the Cessna Aircraft Company for the United States Air Force, its country of origin, and made its first flight in 1949. Commissioned in 1951, it will be sold until 1974 in the United States . It will be produced in 3,431 copies. It will first be used by the Canadian Armed Forces from 1954 to 1973 and widely exported around the world. The Bird Dog performs several types of missions such as artillery adjustment, communication, and pilot training tasks. It will be used during two wars, including that of Vietnam, a war during which 469 aircraft will disappear.