However, the flow of RAAF personnel to the European theatre was slowed by three factors: first, establishment of the massively expanded training process meant that first aircrews trained by the RAAF during the war did not graduate until November 1940; second, RAAF doctrine emphasised the army co-operation and maritime patrol roles; third, the Australian authorities placed great emphasis on a provision of EATS, that Dominion personnel should serve with units from their own air forces, wherever possible. RAAF Article XV fighter squadrons were not operational in Europe until mid-1941.