A plan to turn Kai Tak into a modern airport was released in 1954. By 1957 runway 13/31 had been extended to , while runway 7/25 remained long; night operations were not allowed. Bristol Britannia 102s took over BOAC's London-Tokyo flights in summer 1957 and were the largest airliners scheduled to the old airport (Boeing Stratocruisers never flew there). In 1958 the new NW/SE runway extending into Kowloon Bay was completed by land reclamation. The passenger terminal was completed in 1962. The runway was extended in the mid-1970s to , the final length. This extension was completed in June 1974, but the full length of the runway was not in use until 31 December 1975, as construction of the new Airport Tunnel had kept the northwestern end of the runway closed.