|Quoting justloveplanes (Thread starter):|
The 789 notionally uses the 788 wing, though I heard it was reinforced. I am guessing this goes for the Wingbox as well. What will be the differences?
The 789 has a 10,5% higher MTOW then the 788, i.e. the worst loading case of the wing and the aircraft as a whole would load the wing structure accordingly higher (unless they change the span-wise pressure distribution of the wing which I don't think they have done). I would believe the ultimate load case would be something like the frame passing a thunderstorm at cruise speed, i.e. the ultimate load case is an upward directed gust.
The load-taking structure is the wingbox (central + wings) it needs to be beefed up the 10,5%, the body joint needs to handle a heavier fuselage (compression) and fuselage (longer heavier tube: upper skins tension and lower compression, side shear loads increase) as well. The tail is not experiencing any higher loads most probably (moment arm is longer, i.e. lower forces needed on the tail surfaces) except the dimensioning for a higher risk for tail strikes perhaps. Further the FLG
and MLG fitting points need to be beefed up as well (higher MLW).
[Edited 2011-10-21 00:12:18]