List of United States Army Air Force modification centers

USAAF Modification Centers were World War II industrial plants at which newly-produced aircraft underwent modification to meet the specific requirements of the theatres they were destined for.

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:
 * "the tailoring job of the AAF which fills the gap between the time we decide on an alteration of a plan and the time the factory can incorporate the change into production. To modification centers, operated by contract by commercial airline companies and manufacturers, go most of our airplanes before shipment overseas.  Here they are modernized with the newest equipment available.  Planes also are dressed up or stripped down according to the military requirements and weather conditions of the theater for which they are destined.  Modification is continued on operational aircraft by service personnel in the theaters, where many modification ideas originate."

Sites
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":


 * Birmingham
 * Buffalo
 * Cheyenne
 * Dallas Love Field
 * Daggett, California
 * Denver MAP
 * Evansville, Indiana
 * Fairfax Field, Kansas
 * 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.


 * Kansas City, Missouri
 * Across the river from the Fairfax B-25 modification center


 * Louisville
 * Memphis
 * Niagara Falls Air Force Missile Site|Niagara Falls]]
 * Near the Buffalo modification center


 * Offutt Field, Nebraska
 * Standiford Field, Kentucky
 * St. Paul
 * Tucson
 * Tulsa
 * Vandalia, Ohio
 * At Dayton Army Air Field, which became part of the post-war Army Air Forces Technical Base