Mason From United States of America, joined Jun 1999, 749 posts, RR: 1 Posted (15 years 8 months 3 weeks 2 days 5 hours ago) and read 1100 times:
I have noticed that on the A330/A340, the windows in the rear of the aircraft seem to curve upward toward toward the tail. On larger Boeing aircraft, such as the 767, 777, 747, the windows remain level with the 'cheatline'. Why is this? Is it for structural reasons or what? I will be surprised if anyone can answer this question!
Buff From Australia, joined Mar 2007, 0 posts, RR: 1
Reply 1, posted (15 years 8 months 3 weeks 2 days 4 hours ago) and read 1014 times:
The fuselage narrows towards the rear. To get maximum use of the cargo area under the rear cabin floor area, the cabin floor must be raised. Another way you will notice that the fuselage gets narrower towards the rear, is the seating (at least in our A330's) goes from 2/4/2 to 2/3/2 at row 42. As a passenger comfort, the window line changes as well.
The gradual rise in the cabin floor is preferable to a step.