The station was originally a grass airfield within No. 4 Group RAF. In the early 1940s the airfield was entirely reconstructed with three hardened runways replacing the grass. It re-opened in October 1942 as a station for 77 Squadron RAF and along with RAF Melbourne and RAF Pocklington was known as "No. 42 Base". The squadron had a strength of approximately 20 aircraft and initially used the twin engined Armstrong Whitworth Whitley medium bomber although this was quickly replaced by the Handley Page Halifax four engined heavy bomber which was being introduced. No. 77 Squadron suffered heavy losses during its time at Elvington with over 500 aircrew killed, missing or taken prisoner and almost 80 Halifaxes lost as it played a major part in the Battle of the Ruhr and the bombing of Berlin.