No. 3FS was renamed 103 Fighter Control Unit (103 FCU) on 7 March 1944. The Stuart complex was complete and ready to use on 20 December 1944. The main operations building was a bunker made of 30-centimetre (12 in) thick reinforced concrete designed to withstand a direct bomb hit. It had a mezzanine floor and was air-conditioned. 3 Fighter Sector Headquarters had 32 rooms in the large rectangular concrete building with walls forming various passageways. The building still stands today and is 60 by 42 feet (18.3 m × 12.8 m). 