IV Corps Observation Group

IV Corps Observation Group
Officers and men of the 135th Aero Squadron, November 1918, Gengault Aerodrome (Toul), France
Active	1 July 1918-12 May 1919
Country	United States
Branch	Air Service, United States Army
Type	Group
Role	Command and Control
Part of	American Expeditionary Forces (AEF)
Engagements	World War I St. Mihiel Offensive Campaign Occupation of the Rhineland
Insignia
Identification symbol	135th Aero Squadron 8th Aero Squadron

World War I

The IV Corps Observation Group was an Air Service, United States Army unit that fought on the Western Front during World War I. It was demobilized on 12 May 1919. There is no modern United States Air Force unit that shares its lineage and history.

The IV Corps Observation Group was formally organized on 1 July 1918 by the First Army Air Service at Ourches Aerodrome, France, although its first personnel were organized on 27 June. It was formed for the purpose of operations in the forthcoming American offensives of First Army. Its units consisted of a Headquarters Squadron, the 135th Aero Squadron, arriving at Ourches on 30 July. A second squadron, the 8th Aero Squadron was assigned to the group on 31 August. Both squadrons were assigned to the Group from the 1st Observation Group School at Amanty Airdrome.

The first efforts of the Group were directed towards organization and preparation for combat operations in the coming St. Mihiel Offensive. To this end, the 8th and 135th were designated as Corps Observation Squadrons whose duty it would be to make artillery adjustments, to perform photographic missions of the Corps front, to make long distance reconnaissances together with Divisional work.

On 11 September, the day before the attack, Group headquarters moved to Ménil-la-Tour along with First Army AS Headquarters and IV Corps HQ. Throughout the attack, direct telephone communications were maintained constantly with the flying squadrons at Ourches. The group flew day observation flights over the St. Mihiel Sailent throughout the initial defensive action, then crossing the line and performing reconnaissance patrols over enemy infantry, roads and railroads while the First Army infantry was advancing. It Flew observation missions over the enemy lines, taking photographic strip photos over the entire front. One of the main missions was to photograph the entire corps line front to a depth of 10 km inside enemy territory, about 600 square km.