Does anyone know exactly when the 737 program began? I believe it was 1967. So in reality we have a near forty year old airframe design albeit
"updated." Too bad Boeing did not marry the airframe to a more modern forward fuselage like the 767 or 787 at least. Indeed, as it is the forward
fuselage is derived from the 707 no doubt.
The 737 is the perfect plane that is currently being built for this mission. You aren't going to want to use something bigger, because you're going
to do a lot of low slow flight. Anything bigger just doesn't make sense.
IIRC the 737-800/900 are fly by wire, and the earlier models are hydraulic cables.
This is not the same 737 from the 70's it has a lot of improvements.
However its old age i think was a point in favour. The fact that an airframe had so many hours on its shoulder proved its resistance critical for the
mission intended.
Many people didn't believe a jet could perform like a turboprop, Lockheed wanted to sell an improved P-3...