Originally Posted by
tdracer
Educated guess here, but I suspect that they will simply show that wing tip icing is not critical. This is nothing new - wing anti-ice does not protect the full wing span, just the 'important' parts. The folding wing tips will not have wing anti-ice protection in-flight, so a logic extension is that they can also show that wing tip icing is not flight critical during TO.
And that is exactly what Boeing proposed to and approved by the FAA.