|Quoting Viscount724 (Reply 3):|
I believe that design was to permit more full-size cargo containers to be carried on the lower deck. Doesn't make any difference to passengers (and it's hardly even noticeable in the cabin), but if the floor didn't have that slight curve you would lose several inches of height in the cargo compartment in that area.
The A300, A310, A330, and A340 all share the same fuselage mold lines, differing only in length. The noses and tail sections are all identical.
You are correct. As a consequence of the Airbus design, the rear cabin floor slopes up very slightly so as to accommodate more cans in the aft hold. The windows must slope up with the cabin or they would be next to the feet of the pax sitting in the very rear.
This will not be the case on the A350 and it is not the case on the A380.