Gatwick, other British airports and Tegel Airport in West Berlin. Commercial success Dan-Air's acquisition of three ex-RAF Transport Command Avro Yorks in 1954 resulted in establishment of Dan-Air Engineering as a sister company at Lasham, a disused war-time airfield in Hampshire, to service its fleet as well as other operators. The acquisition of a second DC-3 in 1954 resulted in Dan-Air moving its main operating base from Southend to Blackbushe the following year. The main base transferred to Gatwick in 1960 when Blackbushe closed to commercial airlines. Dan-Air's arrival at Gatwick in 1960 coincided with the entry into service of three former Butler Air Transport Airspeed Ambassadors, the airline's first pressurised aircraft. This heralded the beginning of a major expansion into the IT charter market, including its first charter programme from Manchester. Horizon Holidays was one of the first tour operators to contract the airline's aircraft. The Ambassador fleet numbered seven aircraft by the mid-1960s and operated the majority of the company's IT flights until Comets and One-Elevens assumed the bulk of these operations towards the end of the decade. In 1966, Dan-Air introduced its first pair of ex-British Overseas Airways Corporation (BOAC) de Havilland Comet series 4 aircraft, which made it the second British independent airline after British United Airways to start uninterrupted pure jet operations. This marked the beginning of sustained, steady and mostly profitable expansion. By the end of the 1960s, Dan-Air had become Gatwick's third biggest resident operator after British United Airways and Caledonian Airways. In October 1970, the US Civil Aeronautics Board granted Dan-Air a foreign carrier permit for a five-year period. This became effective on 5 April 1971 and enabled the airline to operate regular transatlantic affinity group charter flights between Britain and the US. To assist with marketing its transatlantic capacity to affinity group charter organisers in both countries, Dan-Air established a new joint venture named Dan-Air Intercontinental in partnership with CPS Aviation Services as a jointly owned subsidiary. Flights began in late-March 1971 with a Boeing 707-321 that was acquired second-hand from Pan American World Airways (Pan Am). The successful launch of Dan-Air's transatlantic joint venture led to the acquisition of a second 707-321 from Pan Am in 1972, and both aircraft continued to be primarily employed on transatlantic charter flights between Britain, Canada and the US until their retirement in 1978. Dan-Air's parent, Davies and Newman Holdings, became a publicly listed