to Wright Field as assistant to the chief of the United States Army Air Corps, also serving as commandant of the Air Corps Engineering School and the chief of the Materiel Division. Once again he held the rank of brigadier general before being promoted to major general on 1 October 1940. World War II Middle East When his immediate superior, Major General Henry H. "Hap" Arnold, was temporarily transferred to the Army General Staff in November 1939, Brett acted as Chief of the Air Corps. In May 1941, he formally became Chief of the Air Corps for a four-year term, but the June 1941 reorganisation that made Arnold the Chief of United States Army Air Forces made the post of Chief of the Air Corps somewhat redundant. Brett was sent to the United Kingdom to determine how the Army Air Forces could better support Royal Air Force Lend-Lease requirements. His recommendation that American labor and facilities be established in the United Kingdom to handle the repair, assembly, and equipping of American aircraft created a stir on both sides of the Atlantic, and was ultimately disapproved by Arnold on the grounds that the personnel and equipment were not available. On August 31 with Major Curtis LeMay as his co-pilot and Brett as Chief of the Air Corps as a passenger, Caleb V. Haynes took off from Bolling Field to begin a round trip journey to Egypt and beyond, conveying Brett to Basra, Iraq, on a special mission. Brett's outspoken criticism of arrangements in the Middle East antagonised his hosts to the extent that the British Ambassador to Egypt, Sir Miles Lampson, complained about him to the Foreign Secretary, Sir Anthony Eden. Air Marshal Sir Arthur Tedder noted that "the charms of General Brett’s company were beginning to pall. After a talk with him on the afternoon of 25 September I wondered in my journal how he and all the American visitors could lay down the law about things of which they knew next to nothing." As a result, Brett was ordered to return to the United States in December. East Indies The outbreak of war between the United States and Japan in December 1941 changed things and Brett received new orders. He first flew to Rangoon and then, in the company of the Sir Archibald Wavell, the British Commander-in-Chief, India, on to Chungking where the two met with Generalissimo Chiang Kai-shek.