The Avionics Building

The Avionics Building

This two-storey reinforced concrete bunker was constructed around 1989 by the US Air Force at Alconbury Airfield. The building is rectangular in plan and partly sunken into the ground, incorporating a drive-through access roadway. Its roof is capped with a rough concrete buster cap specifically designed to absorb the impact of a missile before it could penetrate the bunker.

The building's purpose was to service the electronic components of reconnaissance aircraft and process the data they retrieved. The interior housed life support systems, stainless steel decontamination rooms, electronics workshops, photographic darkrooms, and handling and storage areas. Access is controlled by subterranean portcullis-type blast doors mounted on a hydraulic release mechanism. Beyond the main doors is a suite of decontamination rooms and male and female toilets, with an internal vehicular decontamination facility also present.

The lower floor contained large rooms that housed computers (now removed) where data was downloaded and analysed. One room retains a painted motto above the door reading "Aircrews live by the knowledge, skill, awareness and integrity of their maintenance people". A particularly distinctive feature is the air pressure maintenance system, consisting of compressed air cylinders on the lower floor, designed to maintain internal air pressure in the event of attack. These cylinders remain in place, along with generators, floor surfaces, wall panelling and doors, although most other fixtures and fittings have been removed.

Alconbury Airfield was first acquired in 1938 as a satellite landing ground for RAF Upwood, and during the Second World War was used by Blenheims from RAF Wyton and by the US 8th Air Force in various roles until being returned to the RAF in November 1945. In June 1953 the base was reactivated for the US 3rd Air Force. From 1959, Alconbury became the principal Cold War home to various reconnaissance squadrons. Following the permanent stationing of U2/TR-1 spy planes at the base in 1983, a number of hardened structures were built, including this Avionics building and several Hardened Aircraft Shelters which together have group value. Flying ceased in March 1995 after the Cold War ended, and the base was subsequently released for disposal.