Opened in 1938, it is currently a non-flying facility under the control of the United States Air Force. It is one of three RAF bases in Cambridgeshire currently used by the United States Air Forces in Europe (USAFE). Alconbury, along with RAF Molesworth and RAF Upwood are considered the "Quad-Base Area" due to their close geographic proximity, and interdependency.
RAF Alconbury and RAF Molesworth are the last World War II-era Eighth Air Force bases in England that are still actively in use and controlled by the United States Air Force.
The 423 ABS Commander and his Support Staff, as well as many of the support units and recreational facilities for the Tri-Base area, are located here. The Airman and Family Readiness Center, Lodging Office, Commissary, BX, concessionaires, theater, DoDDS schools and some base housing are also located here. Also located on RAF Alconbury is the 501st Combat Support Wing. This wing ensures four UK-based Air Base Groups (RAF Fairford - 420th, RAF Menwith Hill - 421st, RAF Croughton - 422nd, and RAF Alconbury - 423rd) are resourced, sustained, trained and equipped to exacting command standards in order to provide mission support that enables US and NATO war fighters to conduct full spectrum flying operations during expeditionary deployments, theater munitions movements, global command and control communications to forward deployed locations, support for theater intelligence operations and joint/combined training.
Official website of the Quad-Base installations