Pershing had in September 1917 called for creation of 260 U.S. air combat squadrons by December 1918, but slowness of the buildup reduced that on August 17, 1918, to a final plan for 202 by June 1919. In Pershing's view, the two functions of the AEF's Air Service were to repel German aircraft and conduct observation of enemy movements. The heart of the proposed force would be its 101 observation squadrons (52 corps observation and 49 army observation), to be distributed to three armies and 16 corps. In addition, 60 pursuit squadrons, 27 night-bombardment squadrons, and 14 day-bombardment squadrons were to conduct supporting operations.