"Royal Air Force Radar, 1939-1945." Airborne Interception Radar: AI Mark VIIIB indicator and receiver in the operating position, as seen from the observer's seat of a De Havilland Mosquito NF Mark XIII night fighter. The vizor has been removed from the screen on the indicator unit (top). The receiver unit (bottom) was hinged so as to fold back into the space beneath the indicator unit in order to render access and egress from the cockpit via the door at lower right. Photograph taken at No. 10 Maintenance Unit, Hullavington, Wiltshire.