# What is the aerodynamic impact of the curved/crescenteric wing of the Boeing 787? [duplicate]

From certain angles (see pictures below), the wing of the Boeing 787 seems almost curved/crescenteric in shape, particularly closer to the wing-tip. While the Boeing 787 makes use of "raked wingtips", the curved wingtips seems to be slightly different to Boeing's original description of a raked wingtip in its patents, which seem to be solely reserved to discussing a true "rake" - a section of the wing that has a different sweep angle as the majority of the wing (but each part of the wing is still "straight" - so no curve).

What would the impact of a more "crescenteric" shape to the wing be from an aerodynamic perspective?

Note - I'm using the word "curved", but I do not intend to refer to the wing flex of the wing, which has been discussed in prior posts.

Edit: I've been asked whether this prior question already answers the question of the post. I do not think so, because the raked wingtip explanation refers only to a wingtip that has greater sweep angle than the base wing. But in this case, it seems to me that the 787 actually has a continuously varying sweep angle on the tip, giving rise to the "curve/crescent" shape seen in the image. This is an additional change in geometry/design that might have additional aerodynamic performance benefits.

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• I do not think so, because the raked wingtip refers only to a wingtip section that has a greater sweep angle than the main wing, whereas the 787 wingtip features a continuously varying sweep angle (creating a curved or crescent-like shape). But if Peter (the main commenter) wants to correct me, I'll close the question. Jul 8, 2022 at 18:28
• Boeing certified only one wingtip for the 787, so the other question applies. Your pictures make it look like a continuous curve but it really only has a generous radius in the transition from leading edge to rake along with a blended upsweep. The overhead drawing in the second answer makes the geometry more obvious. Jul 8, 2022 at 22:53
• Hm, I suppose I can close then. Jul 9, 2022 at 0:24