Barker was appointed acting director of the RCAF in early 1924 and he graduated from RAF Staff College, Andover, in 1926. While waiting to start RAF Staff College Course No 4, Barker spent two weeks in Iraq with the RAF to learn more about the uses of airpower. He formally reported on his findings to the Minister of National Defence, and informally to Brigadier General Billy Mitchell, of the US Air Service. One of his achievements in the RCAF was the introduction of parachutes. After leaving the RCAF he became the first president of the Toronto Maple Leafs hockey club and involved in tobacco growing farms in southwestern Ontario.