Boeing 707 center section tanks. Its first flight was on January 11, 1958; 69 turbojet 707-320s were delivered through January 1963, the first passengers being carried (by Pan Am) in August 1959. The 707-420 was identical to the −320, but fitted with Rolls-Royce Conway 508 (RCo.12) turbofans (or by-pass turbojets as Rolls-Royce called them) of 18,000 lb (79 kN) thrust each. The first announced customer was Lufthansa. BOAC's controversial order was announced six months later, but the British carrier got the first service-ready aircraft off the production line. The British Air Registration Board refused to give the aircraft a certificate of airworthiness,
Boeing 707 ground clearance at takeoff. Boeing's answer to the problem was the first wide-body airliner—the Boeing 747. The 707's first-generation engine technology was also rapidly becoming obsolete in the areas of noise and fuel economy, especially after the 1973 oil crisis. In 1982, during the Falklands War, the Argentine Air Force extensively used 707s for long-range maritime patrol, with some of them being intercepted and shepherded away by Royal Navy Sea Harriers, it also led to the conversion of British Nimrods to carry Sidewinder air-to-air missiles after a casual encounter. Trans World Airlines flew the last scheduled 707 flight for passengers