The "Air Service, American Expeditionary Forces" was formally created on 3 September 1917 by the publication of AEF G.O. No. 31 and remained in being until demobilized in 1919. Kenly, an artillery officer, had been a student the previous winter in the Field Officers Course at the Aviation School in San Diego, then served as executive officer of the school to gain administrative experience in aviation matters. Mitchell, Bolling and Dodd were promoted to colonel and given senior positions in the Air Service hierarchy. Bolling was made Director of Air Service Supply (DASS) to administer the "Zone of the Line of Communications" (sic), later called the Service of Supply, and Dodd was named Director of Air Service Instruction (DAI). Kenley proved to be only an interim commander, as Brig. Gen. Benjamin Foulois replaced him on 27 November 1917, arriving in France with a large but untrained staff of non-aviators. This resulted in considerable resentment from Mitchell's smaller staff already in place, many of whom in key positions, including Bolling, Dodd and Lt. Col. Edgar S. Gorrell, were immediately displaced. Mitchell, however, was not replaced and became a source of persistent discord with Foulois.