The airfield was gearing up to train men in flying, bombing, radio and photography for the war effort.

It sailed from Halifax, Nova Scotia on 27 November 1917 and made an unremarkable voyage to Liverpool, England, arriving on 7 December.

In February 1918, the squadron was re-assembled at Spitalgate and shortly afterwards it took over the work of 12 Group, 24th Wing, Royal Flying Corps, becoming the first American squadron to be assigned to duty with a British Flight, however it was commanded by a British RFC officer at the time.

On 16 August, it arrived at Air Service Replacement Concentration Barracks, St. Maixent, which was the primary reception center for new units assigned to American Expeditionary Forces.

Night reconnaissance had been tried with indifferent success by the French and with fairly good results by the British.

Poor equipment was issued to the squadron at the beginning of operations, part of the flares and landing lights being condemned products from other armies.

[3] An effort was made to secure experienced pilots and observers from older squadrons, but this proved impractical.

By diving rapidly, first to the right, then to the left, the 9th squadron aircraft escaped, although the two enemy planes were seen several hundred meters above searching.

Four days later information was received from the Intelligence Department that a night reconnaissance flight had been identified on one of the enemy airdromes.

[3] After the war had drawn to a close, the unit was moved Germany to serve as part of the occupation force of the Rhineland under the Third Army Air Service.

[9] On 15 April 1919, the 9th was reassigned to the VII Corps Observation Group at Trier Aerodrome, where it became part of the infantry liaison school where it assisted in the training of infantry units to work with Air Service units and vice versa.

[9] On 12 May 1919, the squadron first went to the 1st Air Depot at Colombey-les-Belles Airdrome, to turn in all of its supplies and equipment and was relieved from duty with the AEF.

[10] Personnel were subsequently assigned to the commanding general, services of supply, and ordered to report to the Marseilles staging camp.

This article incorporates public domain material from the Air Force Historical Research Agency