Ual747 From , joined Dec 1969, posts, RR: Posted (10 years 10 months 1 week 5 days 7 hours ago) and read 2702 times:
I didn't realize this until I took my first trip on the 744. The wings curve downward at the last few feet on each wing. Also, if you notice sitting in front of the wing, the last 10-20 feet of the leading edges have a different angle than the rest of the wing. What are the purposes of these features?
Ual747 From , joined Dec 1969, posts, RR:
Reply 6, posted (10 years 10 months 1 week 5 days 7 hours ago) and read 2668 times:
I'm not talking about the entire wing flexing due to fuel. I know that the entire wing will flex because of the weight of fuel. I'm talking about how the very tip of the wing, close to the winglet has an extra downward bend to it. Even when the wing flexes upward during flight, there is a bend in the tips.
Wn700driver From , joined Dec 1969, posts, RR:
Reply 9, posted (10 years 10 months 1 week 5 days 7 hours ago) and read 2644 times:
I would guess it has something to do with the fact that the outermost portion of the wing is actually an extension "tacked" onto the original wing design. IIRC, the -4XX 747s have an extra two metres of span (per wing), in addition to the winglets themselves.
To me, it appears that (in flight at least), that last outer portion is actually even (0 degrees to level), whereas the rest of the wing has a dihedral form, giving the illusion of a "droop."
That's my take on it anyway; and worth exactly what you paid for it,
N949WP From Hong Kong, joined Feb 2000, 1437 posts, RR: 1
Reply 11, posted (10 years 10 months 1 week 5 days 6 hours ago) and read 2572 times:
The section of the wings outboard of the No. 1 and No. 4 engines do indeed have a slightly reduced sweepback angle. The purpose of that is to reduce wing flutter. I read about that in a book (forgot the name) that documents the development of the 747.
Na From Germany, joined Dec 1999, 10360 posts, RR: 11
Reply 14, posted (10 years 10 months 1 week 4 days 23 hours ago) and read 2355 times:
Actually the degree of the leading edge angle of all the 747 wings is higher up to the outer engine joint. The reason is aerodynamics. I´m not a technician, but that´s for sure the reason for that. The A380 will be similar. The leading edge angle degree near the fuselage will be higher than on the outer parts.