wrote:
Saying that something is the primary structural member doesn't mean it
is the only structural member. Aircraft structures typically have
several members sharing the load, hence the term "complementary
structure", as they complement each other in carrying the load. The
forward belly skin on my Cessna is .040 in thick, and 44 in wide. This
is approximately 1.75 sq. in. The forward side skins are .032 by 24 in
tall and has approximately .75 sq. in of area. The structural channels
you mention don't have anywhere near this much area, and are themselves
mounted to the forward skins. They are major structural members and
carry significant load, but the skin is still the primary load carrier.



Very good points. Thank you.

Dan