After the war London Transport obtained the contract to operate services between Central London and the various London Airports (at Heathrow, Croydon and Northolt) on behalf of British European Airways, the nationalised "local" airline. Initially they operated a fleet of Commer Commandoes, with classic "deck and a half" bodies, the rear portion of seating raised above the commodious luggage compartment.

These only seated 18 passengers, and the rapidly increasing size of postwar passenger aircraft soon outstripped them. By the early 1950s LT had persuaded BEA to buy a new fleet of coaches, and convinced them that a design based on the forthcoming RF might be rather more expensive in the short term but would be much more long-lived. Park Royal designed a new deck-and-a-half body, but to a mould-breaking shape: the large luggage compartment was still there, with seats above, but now the roof line was continued forwards to give a spacious, modern-feeling cabin.