wrote:
Your average CessBeeMooPip is semi-monocoque in the aft fuselage.

The fuselage skin from the firewall back is the primary structural
member everywhere except at the wing spar attachments, and the landing
gear on Cessnas.


The forward fuselage on the Cessna has heavy structural members.
There are hat-section channels to which the engine mount is attached,
and these run back to the doorposts, which are the primary lifting
members in the fuselage, since the wing's front spars, the spar
carrythrough and the strut attachments are all part of that big
bulkhead. The skin contributes much less in the way of tensile strength
in that area, and it's not a true semi-monocoque. There are sturdy ribs
under the floor and fuselage top, another bulkhead at the rear
doorpost/aft spar attach and carrythrough, and more frame members
behind that, especially around the windows, until we get to the aft
passenger compartment bulkhead. Past that point it's mostly skin. The
framework around the doorframes is fairly heavy to keep them square;
even at that, we find some distortion when we jack the R182 to swing
the gear. If those doors aren't set right, they end up taking flex
loads from the airframe and the hinges eventually break.

Dan