Boeing 707 Douglas competition, Boeing soon realized this would not provide a viable payload, so it widened the fuselage to to allow five-abreast seating and use of the KC-135's tooling. Douglas Aircraft had launched its DC-8 with a fuselage width of . The airlines liked the extra space and six-abreast seating, so Boeing increased the 707's width again to compete, this time to . The first flight of the first-production 707-120 took place on December 20, 1957, and FAA certification followed on September 18, 1958. Both test pilots Joseph John "Tym" Tymczyszyn and James R. Gannett were awarded the first Iven C.
Boeing but the design experience was used in the development of the Model 314 that followed a year later. Overlapping with the period of the YB-15 development, an agreement with Pan American World Airways (Pan Am) was reached, to develop and build a commercial flying boat able to carry passengers on transoceanic routes. The first flight of the Boeing 314 Clipper was in June 1938. It was the largest civil aircraft of its time, with a capacity of 90 passengers on day flights, and of 40 passengers on night flights. One year later, the first regular passenger service from the U.S.