For the first year of the United States' involvement in combat of the war, Pan American continued to operate the airport, providing training to Ferrying Command pilots and ground mechanics assigned to the 18th Transport Transition Training Detachment. With the realignment of Ferrying Command to Air Transport Command on July 1, 1942, plans were made by the Army to assume jurisdiction of the airport. On July 28, 1943, the USAAF 568th AAF Base Unit, Air Transport Command was assigned to the newly designated Brownsville Army Airfield. The mission of the 4th Fighter Operational Training Unit at the airfield was the training of pilots to ferry pursuit planes to the various theaters of war. Training was carried out by AAF instructor pilots, however Pan American Airways retained operations at the airfield flying larger 2 and 4 engine transports to the airport as an overhaul facility. In May 1944, a new mission was developed to train multi-engined pilots at the base. The school began operations in June, and the pilots began to ferry large numbers of aircraft to Panama for subsequent shipment by sealift to Australia.
