weeks at Avord and completing the training course, the 1st Aero Squadron moved to Issoudun Aerodrome in central France on 20 September. However, the training facilities there were not yet ready and the squadron was moved on 19 October to Amanty Airdrome in Lorraine, where the squadron was prepared for active service on the front. On 5 February, Stephen W. Thompson, a member of the squadron, became the first American in the US military to shoot down an enemy aircraft. He was on a bombing mission with a French squadron. At Amanty, the squadron was equipped with Avion de Reconnaissance 1 (AR 1) trainers. Classes were held in radio and machine-gun work and ground training was conducted by French officers. By the end of February 1918, the AR 1 trainers were replaced by SPAD S.XIA.2s. While at the training school, a number of squadron observers were sent to the front line trenches and to other French squadrons for training. On 4 April 1918, the 1st Aero Squadron was assigned to the I Corps Observation Group, Air Service, First Army, and was designated as a Corps Observation Squadron. Movement was made to Ourches Aerodrome for combat duty. In combat, the mission of the 1st Aero Squadron was general surveillance of the enemy rear areas by means of both visual and photographic reconnaissance. These missions were carried out for the purpose of intelligence-gathering and informing First Army headquarters informed of enemy movements and preparations for attacks or retreats of its infantry forces. The 1st identified enemy activity along roads and railroads, ground stations, various storage dumps and airfields, the numbers of fires, and activities of enemy aircraft, and the amount of anti-aircraft artillery was also monitored and reported. Due to the nature of the missions and the depths of enemy area which was penetrated, the missions were carried out at high altitudes, usually between . Bad weather and engine trouble with the SPAD aircraft plagued the squadron upon its arrival at the front, and on 12 April, the first contact with enemy aircraft was made, when Lt Coyle was attacked by three German planes. He escaped, his plane having several bullet holes. The work done by the squadron in its early days of combat operations was judged to be of a high order. A great deal of valuable intelligence was obtained. This was recognized when French General Passage, Chief of Staff of