government department in charge of air transport economic regulation. Cambrian and Western Airways were the first two airlines to be given associate status by BEA in May 1948. These arrangements enabled the latter to contract the operation of a new feeder route between Cardiff and Weston-super-Mare to both of the former, which respectively used Dragon Rapides and Avro Ansons to provide a daily service. East Anglian Flying Services (EAFS) was another early BEA associate. The association agreement between BEA and EAFS resulted in the latter operating a Southend–Rochester feeder service on behalf of the former. 1948 was also the year BEA's reservations department moved to new premises at Dorland Hall, Lower Regent Street in London's West End. BEA made aviation history in 1950 with the world's first turbine-powered commercial air service from London to Paris, using the UK Ministry of Supply-owned Vickers Viscount 630 prototype G-AHRF. By that time, BEA's main operating base at Northolt was the busiest airport in the UK; however, the airline was losing money, which resulted in replacing former BOAC director, Gerard d'Erlanger, who was BEA's first chairman, with Lord Douglas of Kirtleside, as well as appointing Peter Masefield as its new managing director. In April 1950, BEA operated its first service from London Heathrow Airport. Following the provisional introduction of the Viscount 630 prototype on the London–Paris and London–Edinburgh routes, BEA ordered 20 Viscount 701s in August 1950 for delivery from 1953. Also in 1950, BEA informed Vickers of its requirement for an aircraft with 10% lower costs per seat-mile than the 800 series Viscount. This provided the impetus for Vickers to begin developing the four-engined Vanguard high-capacity turboprop in 1953. Expansion, modernisation and commercialisation (1951–1960) Peter Masefield's arrival as managing director (MD) in 1950 marked the beginning of BEA's commercialisation. This entailed introduction of new cost control measures and innovative methods to boost revenue and passenger loads, including off-peak fares on late-evening flights and high-frequency services on the London–Paris route. BEA's new commercially aggressive approach soon resulted in monthly earnings of £1 million. In early 1951, BEA introduced its first "Pionair" class Douglas DC-3, a Scottish Aviation DC-3 conversion featuring British instrumentation and an increased seating capacity of 32. In addition to having 38 DC-3s converted to Pionair passenger carriers, BEA had a further 10 DC-3s modified as "Leopard" class freighters. The same year, BEA introduced its first tourist class on Viking services. This