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 767 to capitalize on its new wide-body's potential for growth, Boeing offered an extended-range model, the 767-200ER, in its first year of service. Ethiopian Airlines placed the first order for the type in December 1982. Featuring increased gross weight and greater fuel capacity, the extended-range model could carry heavier payloads at distances up to , and was targeted at overseas customers. The 767-200ER entered service with El Al Airline on March 27, 1984. The type was mainly ordered by international airlines operating medium-traffic, long-distance flights. In the mid-1980s, the 767 spearheaded the growth of twinjet flights across the northern Atlantic under