USAAF Modification Centers

USAAF Modification Centers were World War II commercial aircraft facilities at which military aircraft underwent post-production changes to meet the specific requirements for combat or specialized roles. The majority of newly produced combat planes were channeled to the modification centers before departing to the active theaters of war.

The use of modification centers avoided disruption to the production lines to incorporate improvements or other changes to the aircraft design.

They were the only "set of field installations" constructed for Material Command. The United States Army Air Forces identified Modification Centers were for:

During 1942, 21 of the modification centers were activated, "eight being operated by commercial airlines and the remainder by aircraft manufacturers. Nineteen of the centers remained in operation at the end of the year after two other centers had been closed out":

1. Built from May–October 1942 for altering new B-25 Mitchells from the nearby Air Force Plant NC, Fairfax's center was a dual hangar of timber frame on the south edge of the airfield near the Missouri River (some alterations were performed on the airport apron.) A west extension and several outbuildings were added to the modification center and in October 1944, it became an adjunct to the final assembly line. Post-war, "Transcontinental and Western Air leased the modification center" for servicing airliners. 2. Across the river from the Fairfax B-25 modification center

The commercial modification centers were distinct from the USAAF ASC domestic depot system which also performed modification as an addition mission function. There were four major depots in the system which expanded to about a dozen during the war. The depots had sub-depots and auxiliary locations. There were also major overseas depot and sub-depot systems which befored addition modifications to combat aircraft.

AAF Study No. 62, Modification of Army Aircraft in the United States, Virginia

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