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,
Longest flights in 23 hours, 19 minutes. In June 1961, an El Al Boeing 707-320 flew a route from New York City-JFK to Tel Aviv averaging 9 hours, 33 minutes. This route was previously tested in December 1957 with a Bristol Britannia. In August 1967, Aerolíneas Argentinas established its non-stop Boeing 707-320B service on a route between Madrid and Buenos Aires with a flight time of 12 hours. The arrival of the more fuel-efficient turbofans made easier the possibility of longer flights. The Aerolíneas Argentinas route was the longest scheduled flight by distance until 1976, when the Boeing 747-SP entered service. In