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 the same 247,000 lb as the standard version. It was a variant for Qantas, thus had its customer number 38. The seven −138s were delivered to Qantas June–September 1959 and first carried passengers that July. The 707-120B had Pratt & Whitney JT3D-1 turbofan engines, which were quieter, more powerful, and more fuel-efficient, producing each, with the later JT3D-3 version giving . (This thrust did not require water injection, eliminating both the system and 5000–6000 lb of water.) The −120B had the wing modifications introduced on the 720 and a longer tailplane; a total of 72 were built, 31 for American