G.R. Patterson III wrote:

The wing spars have to pass through the fuselage. With a low-wing, that means a hump
in the floor. With a high-wing, that means a lwo ceiling at that point. Planes that
carry cargo would rather have a flat floor to ease loading. People, on the other
hand, will step over a hump in the floor and bang their heads on a drop in the
ceiling.

The spar is typically below the floor -- I don't have a hump on the floor of
my Cherokee, and I don't remember ever seeing one in an airliner. The cargo
handlers will might to worry about it in the airliner, of course.

Dunno about "cold weather" planes, but the high-altitude aircraft which come to my
mind are mid-wing aircraft; the U-2 and SR-71.

If a high-altitude plane is designed for ground surveillance, high wing
makes sense. "Cold weather" planes may refer to bush planes, which are also
high wing for obvious reasons.


All the best,


David