Originally Posted by
CONSO
Are you sure about that-?? The ' upper floor' stresses would be significant whereas in a tube, hoop stresses are much easier to handle and uniform ...
Yes!
I could add that the KC-135 also has a fuel tank in the upper fuselage too, mounted aft below the fin leading edge.
Worth noting that around the same time the UK had a go at fitting nice square windows for jet passengers.