777X De-icing
The Boeing symposium guys came around to visit a little while back and not surprisingly, were keen to discuss the 777X. They had some interesting things to say but one thing that appears to still be unanswered is for my question of how the folding wings would affect holdover time.
Holdover times at our company are reduced by 10% unless the flaps and slats are deployed as close to departure as safety allows. This is because fluid degradation is accelerated by the steeper angles of the flaps/slats in the takeoff configuration
So of course, the question is...what kind of holdover can you get with a portion of the critical surface in the vertical position. The answer was that there are ongoing discussions with the FAA. In the end, I suspect the wings will be de-iced when fully extended and then folded up for taxi and no holdover required with perhaps a few caveats.