Boeing 707 lb (57.8 kN) with water injection. Maximum takeoff weight was 247,000 lb and first flight was on December 20, 1957. Major orders were the launch order for 20 707-121 aircraft by Pan Am and an American Airlines order for 30 707-123 aircraft. The first revenue flight was on October 26, 1958; 56 were built, plus seven short-bodied −138s; the last −120 was delivered to Western in May 1960. The 707-138 was a −120 with a fuselage 10 ft shorter than the others, with 5 ft (three frames) removed ahead and behind the wing, giving increased range. Maximum takeoff weight was
1977 Dan-Air Boeing 707 crash The crack found in the failed stabiliser after the accident was thought by investigators unlikely to have been detectable using normal testing means, such as fluorescent dye. It was also thought that the crack had been present for at least 6,000 flight hours before the accident, and before the aircraft had been acquired by Dan-Air from Pan Am. Inspections of the Boeing 707-300 fleet, made as a result of the crash, found another 38 aircraft with similar cracks. </div> 1977 Dan-Air Boeing 707 crash The 1977 Dan-Air/IAS Cargo Boeing 707 crash was a fatal accident involving a Boeing 707-321C cargo