Germany across its territory from 1972 onwards resulted in a decline of scheduled internal German air traffic from/to West Berlin. This was further compounded by the economic downturn in the wake of the 1973 oil crisis. The resulting fare increases that were intended to recover higher operating costs caused by steeply rising jet fuel prices led to a further drop in demand. This in turn resulted in a major contraction of BEA's – and subsequently British Airways' – (as well as Pan Am's) internal German operations, necessitating a reduction in the Berlin-based fleet and workforce in an attempt to contain growing losses these once profitable routes generated by the mid-1970s. Subsidiaries BEA Helicopters The airline carried out trials with its Helicopter Experiment Unit, operating mail services in East Anglia during 1948 and a passenger service from Cardiff via Wrexham to Liverpool (Speke) Airport in 1950. In 1952, BEA established a base at Gatwick on the site of the airport's old Beehive terminal. On 1 January 1964, BEA formed BEA Helicopters as a separate helicopter subsidiary, which established its administrative headquarters and engineering base at Gatwick. Following retirement of BEA's Dragon Rapides, BEA Helicopters took over the scheduled service between Land's End and the Isles of Scilly on 2 May 1964. On 1 September of that year, the service transferred from Land's End St Just airfield to a new, purpose-built heliport at Penzance. BEA Airtours On 24 April 1969, BEA formed BEA Airtours as a wholly owned, non-IATA subsidiary to provide it with a low-cost platform to participate in the then rapidly growing IT holiday flights market, which until then had been the exclusive domain of the independent airlines. On 6 March 1970, BEA Airtours commenced operations from London Gatwick with a fleet of seven second-hand ex-BEA de Havilland Comet series 4B aircraft seating 109 passengers in a single-class high-density configuration. On that day, BEA Airtours' first revenue flight departed Gatwick for Palma de Mallorca. British Air Services Following establishment of British Air Services as BEA's new holding company for its two loss-making regional airline subsidiaries, BKS Air Transport and Cambrian Airways, in March 1970, the corporation acquired a two-thirds majority shareholding in British Air Services in the autumn of that year to ensure its regional partners' survival. While this arrangement transferred overall control of BKS and Cambrian to BEA, it left the former's identities and local managements in place. This