British Commonwealth Air Training Plan was an agreement signed between Great Britain and Canada to train aircrew – including pilots, navigators, bombers, wireless operators and flight engineers – for overseas service. Canada graduated more than 131,000 personnel and established close to 200 schools in communities across Canada. During the war nearly 250,000 members served with the RCAF and over 17,000 lost their lives. Thousands more Canadians served with the Royal Air Force in Britain. By 1945, Canada had the world’s fourth largest air force.