Wazzoo
I also took exception to your comment that winglets don't produce lift by themselves; though that isn't their intention or purpose they certainly do produce lift. In a way that will explain why it isn't helpful to say wingspan is increased with their installation. If a wing is 30 meters in span to the point of winglet attachment and the winglet is 1 meter in length and canted at 77 Degrees, is the span 31 meters? Yes. And No. In plan view, the span is 30.17 meters, the dihedral of the wing with winglet is two separate values, and this assembly will derive lift from both wing and winglet. Likewise Aspect Ratio. It is increased, but because the winglet cants, it is less than what it would be had the wing simply been increased in length by the length of the winglet without the cant. I think we see the same thing in mildly differing perspective. I may have been cautious unnecessarily, if I have offended anyone, I apologize. Regards, Bill