Although the Boeing 707 is known worldwide as the machine

which took civil aviation from the piston engine era into that

of the jet engine, what is very often not known is that its existence

was only made possible by the success of its immediate

predecessor, the KC - 135. Although these two models come from

the same prototype, the Model 367-80, nicknamed `Dash 80'

which first flew in July 1954, they are in fact two radically

different machines sharing only a limited number

of common features.