Next the 88th moved to Souilly Aerodrome on 12 September and was attached to the V Corps Observation Group. From 12 to 17 September the 88th operated over the lines at Saint-Mihiel. The unit took part in the St. Mihiel Offensive from 10 August to 17 September. It had fourteen planes available for service and stood sixteen pilots and eleven observers ready for duty. The squadron in the St. Mihlel attack served under the 5th Observation Group attached to the 26th Division. In the first day's fighting the division reached its enemy objective and the work of the squadron from then until the end of the offensive consisted of reconnaissance work for the division. in watching and reporting upon the enemy's retreat and counter-attacks. Thus the squadron, just having experienced hard and constant fighting on the Vesle, was able to do its part on the new front to help wipe out the St. Mihiel salient. During this time the squadron conducted photographic, corps visual reconnaissance and command missions. Also, on 14 September, the squadron moved again to the Pretz-en-Argonne Airdrome.