Md80fanatic From United States of America, joined Apr 2004, 2777 posts, RR: 9
Reply 5, posted (10 years 7 months 3 weeks 5 hours ago) and read 6175 times:
That last pic shows an unusual amount of flex.....due primarily to the fact that the pilot has extended his slats....which creates a very large roiling motion of the air below the wing increasing pressure greatly (extra lift). That has to be the most that wing can flex before a stress fracture appears. That pic's a keeper for sure.
LVZXV From Gabon, joined Mar 2004, 2041 posts, RR: 36
Reply 6, posted (10 years 7 months 3 weeks 5 hours ago) and read 6152 times:
I remember reading that passengers noted an abnormal amount of wing flex on a BA 741 flying JFK-LHR c.1999. One passenger even described a mild "flapping" notion during the cruise. When the aircraft landed, it was withdrawn from service and immediately inspected. The Jumbo had crossed the North Atlantic with a BROKEN wing spar!!! Beat that Airbus!!!
NoelG From , joined Dec 1969, posts, RR:
Reply 10, posted (10 years 7 months 2 weeks 6 days 23 hours ago) and read 5929 times:
I flew on a MH 747-400 recently from KUL-LHR and it was amazing to see from behind the wing the difference - before pushback the wings (being full of fuel) were bent down at the end, hardly giving enough room for the fuel truck that was there.
After landing, as we taxied in, we went past a BA A320 and the wingtip was higher than we were in the cabin, higher than the A320 as well!
NBGskygod From United States of America, joined May 2004, 836 posts, RR: 1
Reply 12, posted (10 years 7 months 2 weeks 6 days 8 hours ago) and read 5115 times:
The more weight the plane has the more the wing will flap. The C5's wing flapping is so bad it has a damping system to limit it, if that system fails the plane tends to resemble a large bird flapping through the air, and I would imagine not too much fun for those riding inside.
"I use multi-billion dollar military satellite systems to find tupperware in the woods."
WhiteHatter From , joined Dec 1969, posts, RR:
Reply 13, posted (10 years 7 months 2 weeks 6 days 8 hours ago) and read 4989 times:
If the wings DIDN'T flex I'd be worried!
Flexing is designed into the wings of large aircraft. If they just sat there rigid, then where would the changes in stress and vibration be going? A fully rigid wing on a 747 would be under all kinds of changing pressures and much more prone to stress fractures.
Think of dropping a plate on the floor. A bendy plastic one just bounces, a ceramic/pottery one shatters. That flex absorbs a lot of punishment and shock!
Toni_ From Cape Verde, joined Apr 2002, 113 posts, RR: 0
Reply 15, posted (10 years 7 months 2 weeks 6 days 6 hours ago) and read 4910 times:
That's because of the greater wingspan. The 744 has a wingspan of 64 meters, and a 747 classic 59 meters. And also I think the winglets make it a bit easier to detect the wing flex from a distance on a 744. It's the combination of winglets and great wingspan that make the A330 look like a huge albatross stretching its wings while gliding above the ocean.
As for the max a 743 wing can take... I think the first 747 test wing back in 1969 snapped at 10 meters... Still very impressive!