4th Corps Observation Group (World War I)

4th Corps Observation Group
Active	1918–1919
Country	United States
Branch	United States Army Air Service
Type	World War I Command/Control organization
Role	Observation/Reconnaissance

The 4th Corps Observation Group is an inactive United States Army unit. It was last assigned to the IV Corps, United States Army Air Service, during World War I in France. The organization was inactivated in early 1919 as part of the United States withdrawal of forces from Europe after World War I and the demobilization afterwards.

Contents 1 Mission 2 Components 3 Sectors 4 Engagements 5 Aircraft 6 References

Mission

The mission of the group was primarily to keep the friendly command informed of the general situation within the enemy lines by means of visual and photographic reconnaissances. It was called upon to effect, whenever necessary, the adjustment of U.S. artillery fire. In addition, it expected that the group would serve to complete the schooling of pilots and observers and render them more competent to undertake intensive operations elsewhere on a larger and more complete scale.

Components

• 8th Army Observation (Aero) Squadron, 31 Aug – 23 Oct 1918
• 90th Corps Observation (Aero) Squadron, 1 Jul – 21 Sep 1918
• 135th Army Observation (Aero) Squadron, Jul–Nov 1918
• 168th Army Observation (Aero) Squadron, 12 Oct – 31 Nov 1918
• 255th Army Observation (Aero) Squadron, undetermined

(designated for VII Corps)

• 278th Army Observation (Aero) Squadron, undetermined

(designated for VII Corps)

Sectors

Toul, Vosge

Engagements

• St Mihel Offensive, 12–16 Sep 1918

Aircraft

• AR-2 (Avion de Reconnaissance) (French)
• Airco DH-4B (British)

References

 This article incorporates public domain material from websites or documents of the Air Force Historical Research Agency.

• The American Army in the World War, A Divisional Record Of The American Expeditionary Forces in Europe, G Waldo Browne, Rosencrans W. Pillsbury, 1921, Overseas Book Co, Manchester, New Hampshire.