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787 Wing Load-Amazing/Unbelievable!  
User currently offlineReggaebird From Jamaica, joined Nov 1999, 1176 posts, RR: 0
Posted (4 years 7 months 3 hours ago) and read 41883 times:

Preface: Go to the link below and then select the video on the page called "Dreamliners Smooth Landing".

Watching from 53 seconds forward in the aforementioned video, look at how much wing load is unloaded on touchdown. That's almost a visible "flap" of the wing. If I didn't know better, I might wonder how those wings will "hold up" over time.

http://www.cnn.com/video/#/video/us/...009/12/15/natpkg.boeing.flight.cnn

[Edited 2009-12-15 22:13:51]

74 replies: All unread, showing first 25:
 
User currently offlineVctony From United States of America, joined Aug 1999, 455 posts, RR: 0
Reply 1, posted (4 years 7 months 3 hours ago) and read 41899 times:

I wonder the same thing. The wings really seem to "give" a ton.

User currently offline9V-SPJ From United States of America, joined Dec 2000, 748 posts, RR: 0
Reply 2, posted (4 years 7 months 3 hours ago) and read 41871 times:

The wings were built to bend like that. Boeing must have run the design through finite-element analysis many many times to ensure the wings will hold.

9V-SPJ


User currently offlineCosmofly From United States of America, joined May 2009, 649 posts, RR: 0
Reply 3, posted (4 years 7 months 3 hours ago) and read 41773 times:



Quoting Reggaebird (Thread starter):
look at how much wing load is unloaded on touchdown

I have the same question. What would it look like at max load and will such flex affect the wing life expectancy?

789 is going to use the same wing. Imagine flying in turbulence and watch the wing flex  Wow!


User currently offlineVctony From United States of America, joined Aug 1999, 455 posts, RR: 0
Reply 4, posted (4 years 7 months 3 hours ago) and read 41631 times:

One other thought just came to my mind. Most passengers aren't used to being on aircraft with wings that flex that much. One can only imagine that for the first few years of service, the 787 wing flex could end up frightening quite a few passengers.

User currently offlineBlueSky1976 From Poland, joined Jul 2004, 1851 posts, RR: 4
Reply 5, posted (4 years 7 months 2 hours ago) and read 41604 times:

This is nothing unusual. Google any high-performance modern sailplane landing video and you will see the wings behave exactly the same. The reason for "flapping" is the greater flexibility of the carbon-fibre in comparison to the traditional alluminium.

As a matter of fact, you should expect even greater wing flex in A350 due to its bigger span.



All Hail Mighty Triple Seven, The MURDERER of the so-called "Queen"!!!!
User currently offlineULMFlyer From Brazil, joined Sep 2006, 475 posts, RR: 1
Reply 6, posted (4 years 7 months 2 hours ago) and read 41582 times:

Pretty impressive the way it unloads at touchdown.

Quoting Cosmofly (Reply 3):
I have the same question. What would it look like at max load and will such flex affect the wing life expectancy?

At least for metals, fatigue life is determined by stress (cf. S-N curves), not directly by the displacement of the structure, so that the flex itself should have no bearing on it. I'd guess it would be no different for composite structures.



Let's go Pens!
User currently offlineDynamicsguy From Australia, joined Jul 2008, 867 posts, RR: 9
Reply 7, posted (4 years 7 months 2 hours ago) and read 41436 times:



Quoting Cosmofly (Reply 3):
789 is going to use the same wing. Imagine flying in turbulence and watch the wing flex

Same span, loft and planform, but not the same inside. The flex should be similar between the two since the gauge of the skins and structure on the -9 should be greater.


User currently offlineJBirdAV8r From United States of America, joined Jun 2001, 4488 posts, RR: 22
Reply 8, posted (4 years 7 months 2 hours ago) and read 41372 times:



Quoting Reggaebird (Thread starter):
Preface: Go to the link below and then select the video on the page called "Dreamliners Smooth Landing".

Watching from 53 seconds forward in the aforementioned video, look at how much wing load is unloaded on touchdown. That's almost a visible "flap" of the wing. If I didn't know better, I might wonder how those wings will "hold up" over time.

Nit: "Wing loading" for the 787 is not what you're talking about. That does not differ significantly from other aircraft in its class. You're simply referring to wing flex.  Smile

Quoting Cosmofly (Reply 3):
I have the same question. What would it look like at max load and will such flex affect the wing life expectancy?

Jon Ostrower's website had good pictures of the wing loading tests--that'll give you a good indication of wing flex. This wing flex will not detract from the life of the wing, but it will enhance its efficiency. Expect similar results from the A350.



I got my head checked--by a jumbo jet
User currently offlineBoeingVista From Australia, joined Jan 2009, 1547 posts, RR: 2
Reply 9, posted (4 years 7 months 2 hours ago) and read 41273 times:



Quoting Reggaebird (Thread starter):

Yep, I noticed that too! Made me wonder what kind of flex and (momentum) bounce you would get in turbulence..



BV
User currently offlineMarquis From Germany, joined Sep 2005, 274 posts, RR: 1
Reply 10, posted (4 years 6 months 4 weeks 1 day 23 hours ago) and read 40674 times:

It is a combination of a very high lift and highly flexible carbon-fibre wing and effective spoilers reducing the lift on touchdown and roll-out. We will see this kind of wing flex on every new aircraft built with carbon-fibre wings.


Riding the radials...
User currently offlineORDnHKG From United States of America, joined Jul 2009, 191 posts, RR: 0
Reply 11, posted (4 years 6 months 4 weeks 1 day 22 hours ago) and read 40353 times:

I don't really see too much of a deal here. Isn't 747-400 and 777 do the same ? It is only 787's wing bend more than the other two as it is a lighter material.

There are many photos and postcards clearly show the wing tips of both planes bend upwards when airbourne. And when there is turblence, the wingtip go ups and downs instead the whole wing would bounce like 767.


User currently offlineFrancoflier From France, joined Oct 2001, 3712 posts, RR: 11
Reply 12, posted (4 years 6 months 4 weeks 1 day 22 hours ago) and read 40265 times:

Those 'flexy' wings really illustrate the effect of ground spoilers. They effectiely kill any kind of lift the wing was still generating.


Looks like I picked the wrong week to quit posting...
User currently offlineConnies4ever From Canada, joined Feb 2006, 4066 posts, RR: 13
Reply 13, posted (4 years 6 months 4 weeks 1 day 22 hours ago) and read 40191 times:



Quoting Vctony (Reply 4):
One other thought just came to my mind. Most passengers aren't used to being on aircraft with wings that flex that much. One can only imagine that for the first few years of service, the 787 wing flex could end up frightening quite a few passengers.

DC-3's wings flex quite a bit, given the comparative span. But perhaps you don't remember flying on one !



Nostalgia isn't what it used to be.
User currently offlineMEA-707 From Netherlands, joined Nov 1999, 4295 posts, RR: 36
Reply 14, posted (4 years 6 months 4 weeks 1 day 21 hours ago) and read 39410 times:

So will a flexing wing give a smoother flight?
It seems to me that aircraft with relatively hard and small wings, like 727, DC-9, DC-10, A-300 etc are smoother in turbulence then the ones with big wings.



nobody has ever died from hard work, but why take the risk?
User currently offlinePar13del From Bahamas, joined Dec 2005, 6987 posts, RR: 8
Reply 15, posted (4 years 6 months 4 weeks 1 day 21 hours ago) and read 39225 times:

This a/c is also a mass produced product, and there will be a lot of folks travelling on it who will not be aviation "nuts" like a lot of uson this site, imagine their thoughts if and when they do see such flex, they can only relate it to their normal lifes, where if something "bends" that much its only a matter of time.

Whether I'm right or wrong since I'm not too technical, it does give me pause when I think about the last delay to strengthen the wing body join, are the stress's of this flex impacted in that location?


User currently offlineAirbazar From United States of America, joined Sep 2003, 8162 posts, RR: 10
Reply 16, posted (4 years 6 months 4 weeks 1 day 20 hours ago) and read 38980 times:

I think a lot of the wing flex we saw yesterday was probably because the airplane was flying with very little fuel. If you look at a 744 or A330 taking off with empty or light wing tanks you will see the same amount of wing flex. In flight it should not be any more noticeable than on any other airplane.

User currently offlinePEET7G From Hungary, joined Jan 2007, 695 posts, RR: 0
Reply 17, posted (4 years 6 months 4 weeks 1 day 20 hours ago) and read 38985 times:



Quoting Francoflier (Reply 12):
Those 'flexy' wings really illustrate the effect of ground spoilers. They effectiely kill any kind of lift the wing was still generating.

Exactly, what me and my colleague was drooling about when watching it land... nowhere before have I seen this so visible...

This plane is really the triumph of engineering...



Peet7G
User currently offlineAstuteman From United Kingdom, joined Jan 2005, 9944 posts, RR: 96
Reply 18, posted (4 years 6 months 4 weeks 1 day 20 hours ago) and read 38882 times:
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Quoting PEET7G (Reply 17):
This plane is really the triumph of engineering...

That may be true.
But because it "lift dumps" on landing?
That's hardly new....

Rgds


User currently offlineGlideslope From United States of America, joined May 2004, 1601 posts, RR: 0
Reply 19, posted (4 years 6 months 4 weeks 1 day 20 hours ago) and read 38413 times:



Quoting Vctony (Reply 4):
One other thought just came to my mind. Most passengers aren't used to being on aircraft with wings that flex that much. One can only imagine that for the first few years of service, the 787 wing flex could end up frightening quite a few passengers.

That's why there are Cars, and Trains.  Embarrassment



To know your Enemy, you must become your Enemy.” Sun Tzu
User currently offlineRevelation From United States of America, joined Feb 2005, 12286 posts, RR: 25
Reply 20, posted (4 years 6 months 4 weeks 1 day 20 hours ago) and read 38371 times:



Quoting Vctony (Reply 4):
One other thought just came to my mind. Most passengers aren't used to being on aircraft with wings that flex that much. One can only imagine that for the first few years of service, the 787 wing flex could end up frightening quite a few passengers.

Certainly questions will arise.

Quoting BlueSky1976 (Reply 5):
This is nothing unusual. Google any high-performance modern sailplane landing video and you will see the wings behave exactly the same. The reason for "flapping" is the greater flexibility of the carbon-fibre in comparison to the traditional alluminium.

I remember flying in a Duo Discus with 20 meter wings for the first time after only being in aluminum sailplanes with 15m wings. It is disconcerting to see big wings flap that much even for an aviation enthusiast never mind an average passenger. Questions will be asked. I'm sure the airlines will be prepared with answers.



Inspiration, move me brightly!
User currently offlineGlideslope From United States of America, joined May 2004, 1601 posts, RR: 0
Reply 21, posted (4 years 6 months 4 weeks 1 day 20 hours ago) and read 38373 times:



Quoting PEET7G (Reply 17):
Exactly, what me and my colleague was drooling about when watching it land... nowhere before have I seen this so visible...

This plane is really the triumph of engineering...

...and then some.  checkmark 



To know your Enemy, you must become your Enemy.” Sun Tzu
User currently offlinePEET7G From Hungary, joined Jan 2007, 695 posts, RR: 0
Reply 22, posted (4 years 6 months 4 weeks 1 day 20 hours ago) and read 38216 times:



Quoting Astuteman (Reply 18):
That may be true.
But because it "lift dumps" on landing?
That's hardly new....

Rgds

You should know, that was not the reason I wrote that...  Yeah sure



Peet7G
User currently offlineTISTPAA727 From United States of America, joined May 2007, 321 posts, RR: 2
Reply 23, posted (4 years 6 months 4 weeks 1 day 19 hours ago) and read 37401 times:



Quoting Astuteman (Reply 18):
That may be true.
But because it "lift dumps" on landing?
That's hardly new....

 checkmark 

It is definitely amazing to watch but it is nothing new. Also, I do not think passengers will overreact. With the introduction of massive winglets on 737, 757 and 767s around the world, people are going to be more used to see part of the wing so high. (Granted, these are completely different than wing flex but at quick glance the casual observer notices height first). Also, think of a current generation aircraft in high turbulence. I have never heard any passenger say, "OMG the wing!". Today's aircraft wings flex a lot in turbulence and are quite noticeable by us, but not the casual observer.



Don't sweat the little things.
User currently offlineSEPilot From United States of America, joined Dec 2006, 6794 posts, RR: 46
Reply 24, posted (4 years 6 months 4 weeks 1 day 19 hours ago) and read 36425 times:



Quoting MEA-707 (Reply 14):
So will a flexing wing give a smoother flight?
It seems to me that aircraft with relatively hard and small wings, like 727, DC-9, DC-10, A-300 etc are smoother in turbulence then the ones with big wings.

This is due to higher wing loading, which effectively "smooths" the bumps. Wing flex will do the same with lower wing loading, plus the 787 FBW system is designed to help much as active headsets cancel out outside sounds by introducing opposite sound waves. I would expect the 787 to be much smoother in turbulence than any current airliner. As to the flex issue, because CFRP does not fatigue the way metal does, it can tolerate much more flexing than can aluminum. They could design aluminum wings to flex just as much as the 787's do, but they wouldn't last very long. Likewise, they could design CFRP wings to be just as stiff as the aluminum wings, but they would be heavier than necessary and would not give the benefits of the smoother ride that the flexible wings will.



The problem with making things foolproof is that fools are so doggone ingenious...Dan Keebler
25 BrouAviation : People new to the 747-400 also look with a slight fear to the wings, albeit being in service for so many years, I am willing to bet the 747 is very h
26 Stitch : I think the wing flex is something to be excited about, not frightened. The 777's wings flex something fierce in flight and based on the artist render
27 CM767 : Exactly, I fail to see why passengers would be afraid, I do not see more flex than on a heavy 747, there are a few pictures out there showing the sam
28 AerLingusA330 : Well, if you look back at that video you notice that the wing flex on landing is exaggerated because the wing spoilers are deployed right as the mains
29 MD80fanatic : I'm not so sure of the efficiency of maximum wing flex design. Much of the lifting surface is far from perpendicular to the force of gravity, meaning
30 EA772LR : I agree. I sent the video to my father (he loves airplanes as well) and he was blown away by the flex in the wing. I also work with a guy in his earl
31 Nycbjr : care to share your reasons? or is that another topic?
32 Post contains images MD80fanatic : Patience is a virtue (and there are still two weeks left in 2009)   I couldn't understand the rush, especially considering the source of the latest
33 Stitch : If it's ready to go (and it certainly appeared to be), why wait?
34 Viaggiare : Eventually they'll get used to the fact that it must flap its wings from time to time in order to remain airborne.
35 Revelation : Just as long as it doesn't stop on a telephone wire to catch a rest and take a dump!
36 Rdwelch : Not to get off topic, but the wing flex of the B-52 is pretty amazing in its own right. Gus
37 474218 : Very well! If the wing did not flex they would fail much sooner.
38 Acabgd : Huh? Compared to the size of the body, the 727 had massive wings with enormous surface area!
39 Rheinbote : Makes you wonder how somebody who loves airplanes could have ignored artists impressions of the 787 for the past five years. The wing flex was pretty
40 Rcair1 : It will likely be smoother - the lower wing loading and the flex will help absorb some turbulence - at least that is what I believe I've heard. Helic
41 Amccann : While I agree with your idea in theory it is not completely true and you seemed to have answered your own thought. There is no point in designing a s
42 FLALEFTY : Absolutely right-on! The thing that amazes me about this plane is the wingspan. I can see the 788 being a favorite from "hot and high" airports thank
43 WROORD : But the 787 was advertised as a revolutionary project which would mitigate the effect of turbulance provideding much smoother ride for the pax. This
44 Tdscanuck : As good, or better, than current designs. The FAR's regarding fatigue life haven't changed, so they have to be at least as good just to get certified
45 MD80fanatic : A slight correction if I may. A -force- is always generated perpendicular, but lift is the component of force positioned directly against the gravity
46 Antskip : I once watched amazing flexing(s) of the wing(s) on a Comet 4 during a thunderstorm on a flight between Mauritius and NBO in the 1960's. But I am not
47 Astuteman : Again, the 787's wing is almost completely identical to the A330's wing in both wingspan AND total area. No surprise I guess, as the plane itself is
48 MotorHussy : Sweet landing, pretty to watch! Thanks for the post.
49 FlyABR : does that inclue the A333? the few times i've been on a loaded A333...it took alot of runway to get into the air ... it's a great plane...but certainl
50 Post contains links Rheinbote : Making wings flexible actually is a means to make aircraft (large ones with high inertia) less susceptible to being tossed around in turbulence. Gust
51 Astuteman : Amongst the best of widebodys for field performance according to ther charts True enough But then no widebody is.. Rgds
52 Tdscanuck : That's mostly a mission thing...a 757 is far more likely to be operating at the low end of its weight range than an A330. A lightly loaded A330 is al
53 MD80fanatic : You guys know more abut this bird and it's first excursion than I, so can I ask a question? What was the take off weight this first flight? I can only
54 Stitch : I've never been a fan of the aesthetics of the A330, mainly because the engines are too small for the fuselage and wing (the A340 looks much better b
55 FlyABR : i was basing it more off seat-of-the-pants feel...which doesn't make it very scientific ... that said, i recently flew on a 764 out of MAD...and it c
56 WingedMigrator : It's those thick and curvaceous intake lips
57 Rcair1 : This statement cracked me up - not that I'm disagreeing. But for me (in the business I'm in), we don't consider it mass produced till we hit, oh, say
58 Post contains links and images Mirrodie : Actually, I think of it in opposite terms. The only other new airplane I have taken interest in is the A380. When I took the following photo and look
59 Stitch : Could it be due to the fact that the A380-800 is "over-winged"? Or would such a scenario result in something more like the 787-8, where the wings per
60 WingedMigrator : It looks like sag but it isn't. The A380's wings are gulled to provide clearance for the inboard engine without making the landing gear longer than i
61 Astuteman : That's one HUGE wing that's actually incredibly light for what it is, and is SUPERB at taking to the sky........... Sit on an A380 and watch that win
62 SEPilot : Hey, I can certainly appreciate the technology that went into it, even though I am firmly of the opinion that the time for aluminum airliners is pass
63 Astuteman : Don't disagree with that. That is sometimes true, too. However.. Obsolescence in this way is typically at the whole system level, and the example you
64 MD-90 : Can you imagine what it would look like if Airbus had tried to make the A380 with the same level of CFRP as the 787?
65 Astuteman : Some of the autoclaves might have been a tiny bit bigger.. (And the A380 has some BIG ones...) Rgds
66 RSBJ : Don't have time to read the whole thread to see if this was already mentioned...appoligies. But all the video and pics we have seen are with the flaps
67 WingedMigrator : A gentle reminder that an A380 contains about the same amount of CFRP (pound for pound) as a 787... in the neighborhood of 35 metric tons. Yes, the p
68 JoeCanuck : The newest 2 Airbii have gone the CFRP route; the A400 and the 350...so it seems the aircraft manufacturers themselves have decided the game has chan
69 Post contains images DocLightning : So I was watching a hawk today and when he was gliding, his wings looked like this: (Yes, I know that's not a hawk). Now, this bird is in "clean" con
70 Areopagus : Note the multiple slots on the eagle's wingtips. How long until airliner wings get that treatment?
71 Tdscanuck : There's an appallingly ugly apparition that did this a while back...it looks like a Venetian blind on the end of the wing. I know 2H4 has a photograp
72 Astuteman : Which is great, but if you look at the REAL efficiency kings, the big seabirds, they have "gull-wings" with more than a passing smilarity to the A380
73 WingedMigrator : I think you missed the adaptive camber, too. 'Control surfaces' are such an artificial notion: everything's a control surface! Somebody's going to th
74 Post contains links Rheinbote : It's here: http://www.airliners.net/photo/Stemme-S10-V/1041849/M/
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