Railway Air Services (RAS) was a British airline formed in March 1934 by the Big Four railway companies (the GWR, LMS, LNER and SR) and Imperial Airways. The airline was a domestic airline operating routes within the United Kingdom linking up with Imperial's services. Prewar routes The airline's main operating and maintenance base was at London's Croydon Airport pre- and post-war, and at Liverpool Airport during World War II. The most important RAS route flown was between London and Scotland (London-Birmingham-Manchester/Liverpool-Belfast-Glasgow). The trunk service commenced on 20 August 1934, using the airline's newly delivered DH.86 Express biplane airliners, which operated once daily in each direction. The service was mainly aimed at passengers wishing to connect at Croydon Airport with IALs flights to the Continent. RAS were unhappy with winter operations at Manchester's small airfield at Barton Aerodrome and the flights switched to the larger Liverpool (Speke) from the late October, resuming through Barton on 15 April 1935. Routes operated from Cardiff Municipal Airport included Cardiff to Plymouth and Cardiff to Liverpool and commenced in 1934. World War II In 1939, the operation of civil aircraft was restricted and part of the RAS fleet was placed under government control. The aircraft were involved in communications flights for the military within the British Isles. By 1940, the Royal Air Force had taken over all the military communications tasks and the airline returned to flying routes 'of national importance'. In practice, wartime operations were restricted to the Liverpool-Belfast-Glasgow route carrying government and other 'priority' passengers and mail. Postwar operations Railway Air Services resumed peacetime flights in early 1946, now also using their newly acquired Avro Ansons and ex-RAF Douglas DC-3 Dakotas. A number of ex Luftwaffe Junkers Ju 52 trimotor aircraft were used during 1946/47 before retirement and scrapping. The airline operated its Dakotas, with their higher passenger carrying capacity, on their non-stop flights from Croydon to Glasgow (Renfrew) Airport. A new twice-daily RAS scheduled service commenced on 29 July 1946, using the Avro Ansons, which linked linking Croydon with Manchester Ringway and Belfast (Nutts Corner) Airport. Nationalisation In August 1946, the UK government formed the British European Airways Corporation (BEA) a state-owned airline. The airline was given a monopoly of scheduled air services within the United Kingdom and to continental Europe. From 1 August 1946 RAS operated all its services on behalf of BEA until it ceased operations on 31 January 1947