Original Item: Only One Available. A fine WWI tunic featuring a rare Corporals chevron with embroidered Air Service insignia on right sleeve, Third Army three piece wool patch insignia on left shoulder, correct buttons, collar tabs, medal ribbon and overseas service bar. The tunic is a high quality tight weave light weight wool pattern, designed for summer flying. Measures approximately 38 around the chest with four pockets and orange stitching.

In January 1917 the CSO advised the House Committee on Military Affairs that during 1917 the Aviation Section would increase in size to 13 aero squadrons: four land plane squadrons based in the United States, three seaplane squadrons to be based in U.S. possessions overseas, and six reserve squadrons for coast defense. By the time of the United States entry into World War I in April, three squadrons (1st and 3rd in the U.S., 2nd in the Philippines) were in service, two (6th for Hawaii and 7th for the Panama Canal Zone) were organizing, and two (4th and 5th, to be based in the continental U.S.) had yet to receive personnel. In March, for planning purposes, the Army Chief of Staff proposed new tables of organization and authorized a total of 20 squadrons, including an additional squadron in the U.S. and six additional for coast defense. However the plan was never implemented because of the war and only 131 of the required 440 officers had been assigned.

During the following year, until the statutory responsibilities of the Aviation Section were suspended for the duration of the war plus six months by Wilson's executive order, the Aviation Section rapidly mobilized "aero squadrons" for a multiplicity of needs, including combat operations. This resulted in a conglomeration of several classifications by function, as flying squadrons were only a portion of the units required by the Aviation Section and by its successor, the Air Service:

• Service squadron: Flying units equipped with planes and flying personnel. Enlisted personnel assigned to the squadron consisted of mechanics, radio operators, machine gun armorers and chauffeurs. Service squadrons were eventually classified as "pursuit", "observation" or "bombardment" according to their combat role.

• School squadron: Support units consisting primarily of aircraft mechanics, performing their work in the hangars and shops at training bases for pilots and observers.

• Construction squadron: Units which built new airfields, smoothing and grading a field for aircraft landings and takeoffs. They also erected hangars, barracks, shops, and all the other infrastructure (roads, electricity, water, sewer) needed to establish a new airfield. In the Zone of the Advance in France, new airfields were established quickly as the front line changed.

• Park squadron (also known as "air park"): Logistical units whose mission was to supply the equipment and supplies necessary for the other squadrons to operate.

In the Air Service of the AEF, one squadron historian estimated that for each flying ("service") squadron, there were at least five support squadrons to maintain its aircraft, airfields and stations, beginning with the park squadrons. Behind them were:

• Depot squadrons to provide a supply base and a reception point for new aircraft being delivered to the flying squadrons.

• Repair squadrons at major repair facilities where new aircraft were assembled and parts from old aircraft salvaged.

• Replacement squadrons for processing and assigning incoming personnel for the flying squadrons.