In 1917 and 1918, the Royal Flying Corps (RFC) and its successor, the Royal Air Force (RAF), directed an ambitious flight training operation in Canada. The scheme had no precedent, but it inspired later, similar schemes­—the British Commonwealth Air Training Plan (1939-1945) and a general program to train North Atlantic Treaty Organization aircrew at Canadian centres from 1952 onwards. The importance of air power had been growing from the outbreak of the First World War. Aircraft mapped enemy trench systems, directed the guns shelling those trenches, and warded off opponents’ machines intent on performing the same tasks. As aircraft became more vital to waging war, Britain required greater numbers of airmen. Late in 1916, an RFC expansion plan suggested formation of 35 new training squa...