|Quoting ZaphodHarkonnen (Reply 8):|
I believe these are different to the winglets that will appear on the MAX. These are an aftermarket option offered by an independent company. The MAX ones are also called something else as the name scimitar is a trademark.
1) The winglets are called Split Scimitars (by Aviation Partners Boeing) as installed on the 73G family. The 73M family will have a Boeing product called the Advanced Technology Winglet (ATW
) as standard equipment. Not sure if Boeing plans to certify a nonwingletted version.
2) The upper wing-like element of both winglets operates, of course, as a standard winglet and reduces span-wise flow and moves vorticity due to induced drag aftward on the wing. The downward wing-like element does not extend outboard of the upward wing-like element while the aircraft is on the ground, but as the aircraft rotates to take flight, the wing flexes upward and that rotates the wingtip inward. This inward rotation of the wingtip causes the lower wing-like element to extend further outward, providing an increase in overall span.