Winglets on the B-777?

[FlyNavy]

This snippet caught me eye tonight (in a company newsletter). Certainly, the "A" market (I refer to them Vanilla) and -200ER models could benefit from such a modification. I'm surprised Boeing decided to approach AA and DL over this, as both carrier's 777 fleets are stretched to the limits (AA to a lesser extent at present). Surely Emirates would jump on this as well, though they have recently announced plans to dump some of their Vanilla birds.

Aviation Partners Boeing has approached Delta and American Airlines about providing a B-777 to be used as a test bed for a winglet modification to the aircraft. Delta has neither accepted nor declined the offer to participate in the program, but finds the potential benefits appealing. Since the real fuel savings from a winglet aircraft comes in cruise flight, who better to evaluate the savings than us [Delta]. There could be some real savings on the BOM-JFK run, which is over sixteen hours.

[Idlewild]

Don't raked offer better performance than winglets on aircraft/wings that size? Is there a way to modify a plain wing into a raked easily?

[cancidas]

i thought the 777 wing was desinged to not require a winglet on it. the raked wingtips were borrowed from the 767-400 for the ER versions because they were more efficient than winglets.