Originally Posted by
Mk 1
How about a folding wingtip which does not affect the basic controllability of the airframe is extended or retracted asymetrically?
Having one retract and the other not will always cause a lift asymmetry. If it doesn't affect the aircraft at all, you might as well just leave the entire wingtip off in the first place.
What I think will happen: For the next round of weight savings on the 777X, the movable tip will be moved from a fixed item to an optional item, removing the weight penalty from the performance guaranties. As no airline will want to accept the penalty, it will die a quiet death. I think long range aircraft are not the best application for this technology, due to the increased payload-range penalties. They also do not spend a lot of time on the ground.
One thing I must say for Boeing, is that at least they are taking the effort now of trying to certify it, so maybe it will work in the future. With the previous tip on the original 777, any airline wanting the folding tip basically had to arrange and pay for the certification as well, clearly indicating Boeing did not want anyone to actually take the option.