In the early 1970's while stationed at the Pentagon a bunch of us worked on
scaling various WWII aircraft.

It became immediately obvious that there were were two things we could NOT
scale: the pilot and the engines.

Pilot-relative scaling was the most productive in that designing an airframe
just large enough to accomodate the pilot usually afforded a wider range of
engine options.

The PBY was among several pilot-relative designs. With the pilots head in the
pylon, the thing came out with a span of about 34' and, at least on paper,
could fly with a pair of C-85's.

The C-130 (with four VW engines!) came out looking pretty good... on paper.

I don't think any of the scaled designs ever flew although. The
engine-relative P-38 may have done so. All of Kelly Johnson's designs
scaled-down rather well.

-R.S.Hoover