I remember seeing on this site an A330 derivative that was either clipped by another plane in NYC or clipped a pole leaving the winglet hanging. The interim fix was to finish removing the winglet, cover the end with speed tape, and fly it home with a passenger load. People said the winglet was not needed by regs but fuel burn would be higher so additional would need to be loaded. Inference by several on this thread has been the extended wing tip on the 777X is asking for disaster. I pointed out there are any appendages on the wing that move during flight making them more susceptible to failure. I have no idea if the 777X will need to be tested for flight while folder - Boeing likely already has wing tunnel test results and knows the answer. Folding wings - much ado about nothing.