RE: Boeing 787 Wing Bend Test......

**brad kaste** · October 28th, 2011, 16:14

This is a recent wing strength test video on the new Boeing 787 which has a ‘composite wing’ versus an ‘all metal wing’. This particular wing test was taken to 50% beyond the design limit of the 787 wing without a structural failure -which is quite an accomplishment. Still makes a pilot cringe to see a wing bent this much even if it is a controlled test.

http://787flighttest.com/hanger/wp-content/plugins/flash-video-player/mediaplayer/player.swf?streamer=rtmp://cp81820.edgefcs.net/ondemand/tpn/firstflight/&file=TestLog4.flv

**Wing_Z** · October 28th, 2011, 16:33

Always a tense moment... but of course all airliners go through this as part of certification, and the wing is designed to go to 150% of design load.
The B777 wing bust at 154%
[YOUTUBE]Ai2HmvAXcU0[/YOUTUBE]

Wonder why they didn't show the 787 wing going to destruction?

**pfflyers** · October 28th, 2011, 18:52

I'm not sure their test rig was capable of bending the wing far enough to cause the type of obvious catastrophic failure that metal wings exibit.

**Dev One** · October 28th, 2011, 23:23

Ornithopters next?
Must remember though that although it looks a great deal of deflection, plastics (including laminates & composites) have a higher flexural modulus than most metals.
Still, very impressive, & quite a design feat for the bits that connect to the main structure to allow that much movement - Flaps, slats, spoilers, lift dumpers, not to mention fuel & hydraulic pipes, cables even.
Keith

**hairyspin** · October 29th, 2011, 12:59

Originally Posted by Wing_Z

Wonder why they didn't show the 787 wing going to destruction?

I don't think anyone wants to see a composite wing fail, even if it's a test. Lots of black straw when the carbon fibre fails, plus it'd take Boeing a fortnight to sweep that building clean of resinous dust - and I didn't see anyone wearing dust protection respirators with these hard hats and high-viz vests.

**Wing_Z** · October 29th, 2011, 13:48

Well they do clear the building, in case it does go!
Actually looking at the amount of deflection to achieve 150% load...
I wonder in practice if it would ever see an aerodynamic load like that - the thing would just bend away and shed load!
OK it would drop like a stone, too...