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Boeing's New 787 Wings — Amazingly Flexible 564

Posted by ScuttleMonkey
from the reed-in-the-wind dept.
An anonymous reader writes "Boeing is making the wings of its new 787 out of carbon fiber instead of metal. That means the wings are so strong and flexible that they could bend upward and touch above the fuselage — or come close. The company is expected to deliver the first 787 to All Nippon Airlines in May 2008. 'Boeing has completed static testing of a three-quarter wingbox, but engineers are still considering whether to limit testing of the full wing to a 150% load limit held for 3 sec. or to continue bending it to see when it breaks. 'There's a raging debate within the engineering team to see if we should break it or not,' says [787 General Manager Mike] Bair.'" They have come a long way in wing flexibility.
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Boeing's New 787 Wings — Amazingly Flexible

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  • by TheSHAD0W (258774) on Wednesday June 27, 2007 @03:30PM (#19667039) Homepage
    Breaking it isn't necessary for certification, but Bair says the wing is so strong and flexible that there's been talk that maybe it could be bend far enough for the wingtips to touch above the fuselage--or come quite close.
    • by kannibul (534777) on Wednesday June 27, 2007 @03:34PM (#19667111)
      Enter the flapping apparatus! It'll make the passengers feel more comfortable, having their plane flap it's wings!
      • Ornithopter? (Score:4, Informative)

        by dakirw (831754) on Wednesday June 27, 2007 @03:52PM (#19667407)

        It'll make the passengers feel more comfortable, having their plane flap it's wings!
        You mean like an ornithopter [wikipedia.org]?
      • by arivanov (12034) on Thursday June 28, 2007 @02:10AM (#19672517) Homepage
        Comfortable? Forget it. I hate flying on any of the new Boeings. Have you flown on a 777 in a storm? You can actually see the fuselage bend and buckle and the luggage compartment above the central seats move by nearly a foot left and right. While the engineer in me knows that this way it is actually more likely to survive through turbulence and load, the little scared mammal in the depth of my brain (which everyone has) screams "run for your life". No thanks, had that twice and enough is enough. From there on I try to chose long haul flights by Iberia or one of the other airlines which operate "boeings and dogs not allowed" policy and use A340 on transatlantic routes. It is considerably more comfortable.
        • Re: (Score:3, Interesting)

          by DieByWire (744043)

          I hate flying on any of the new Boeings. Have you flown on a 777 in a storm? You can actually see the fuselage bend and buckle...

          As far as the 'new Boeings' part, it's not really a new thing. If you sit in an aisle seat far back in a 747 and sight down the seat line, you can see the fuselage bend. As far as I know, there has never been an inflight structural breakup of a 747 that was due to turbulence. They've had passengers killed by turbulence (UA over the Pacific), engines thrown in turbulence (Anchorage), but never has one come apart due to turbulence that I'm aware of.

          Still, I can see that it would make some people nervous.

    • Please don't do this during my flight, thanks...
    • YMCA (Score:5, Funny)

      by everphilski (877346) on Wednesday June 27, 2007 @03:51PM (#19667389) Journal
      I want to see the 787 do the Y-M-C-A :)
  • by chris098 (536090) on Wednesday June 27, 2007 @03:30PM (#19667049) Homepage
    From the article:

    No one's ever really tried that before, so testing is critical.

    Since this seems like such a new concept (please correct me if I'm wrong; I don't follow plane technology too much), it would just seem prudent to try bending the wings until they break... how can they make accurate judgments and calculations without knowing exactly how much stress the wings can take before snapping?
    • Re: (Score:3, Interesting)

      by stoolpigeon (454276) *
      I watched a documentary about the 767 (I think that was it anyway) where they showed them snapping the wings - and it was pretty awesome. Off to search the intarwebs- that video has to be out there.
    • Re: (Score:2, Interesting)

      by Fireflymantis (670938)
      I wonder what the argument for 'not' testing these wings up to breakage point?
      • Re: (Score:3, Insightful)

        They might as well - its not like they can then just stick it on a production model and sell it, since its already been over-stressed. Any failure post-production would bring HUGE lawsuits.
      • by nelsonal (549144) on Wednesday June 27, 2007 @03:37PM (#19667175) Journal
        It's potentially more dangerous than an alumnium wing, 150+% of design load has to be a substantial amount of energy stored in the wing, and while aluminum will deform in failure (converting most of the energy to heat) carbon fiber seems more likely to shatter.
        • by steveo777 (183629) on Wednesday June 27, 2007 @03:51PM (#19667397) Homepage Journal
          What I think will happen is that tips will meet. They'll try to compress the wings vertically, but before any definitive results are in, there will be a very loud "SPROING" in which case, the wings will be freed from their restraints. They will smash toward ground, propelling the plane into the air. As they bounce back to equilibrium the wings will flap carrying the plane roughly 1000km in the direction it was pointed. Eliminating the need for any fuels on short trips. Carbon Fiber FTW!
        • by Dare nMc (468959) on Wednesday June 27, 2007 @04:25PM (#19667915)

          while aluminum will deform in failure (converting most of the energy to heat) carbon fiber seems more likely to shatter.

          of course their is a downside to most changes.
          by deform, you mean yield [wikipedia.org] so, yes if you exceed the limit of carbon fibre you likely have snapped, where as aluminum, you have destroyed the structure of the frame. So if they both exceeded this limit at the same load, the aluminum may allow you to make it through one event.

          For this to be obviously safer, you need:
                1) the yield points would have to be very close.
                2) it must be a single yield event (not repeated yield points, leading to a quick fatigue failure)
                3) you must know the event occured so that you will replace the yieldied aluminium part, before the next event.
                4) the yield event would still have to be in the yield strength of the aluminum, and not exceed it to the point of failure.

          I think that is the issue, all of these are false. Carbon fibre has a much higher yield point, the aluminum wings constantly need inspected for fatigue cracks, and with each cycle they become closer to the point of failure.

          With the carbon fibre, as the wing bends, it is probably designed to self limit the load. Since the aluminimum cannot survive the same amount of movement, it cannot self regulate (it bends, which makes it hot, which makes it softer, which makes it bend more which makes it hotter and softer,...)

          of course it takes alott of energy to bend carbon fibre also, so it is releasing energy as heat as well. Granted aluminum is a much better heat conductor, so it would naturally transfer that heat better. But carbon fibre is known to stay stronger at high temperatures than aluminum.
      • Re: (Score:3, Informative)

        by Kadin2048 (468275) *
        Not being privy to the argument I can only speculate, but I bet that there are other tests that people would like to perform on the prototype wings, which they won't be able to do if they break them during the load test.
    • by LWATCDR (28044) on Wednesday June 27, 2007 @03:38PM (#19667189) Homepage Journal
      "how can they make accurate judgments and calculations without knowing exactly how much stress the wings can take before snapping?"
      You don't need to. You test to 150% of the rated load factor.
      I think for for airliners it is +3 -2 Gs. It has been a few years since I needed to know it.
      So you would test the wing to 4.5 Gs.
      If it passes it is good to go.
      Testing to destruction is good data to have but not required. If they get to to a 9 g load and the wing doesn't break I really think they could stop. Any airliner pulling a sustained 3 Gs will end up on the nightly news.
      • Re: (Score:3, Interesting)

        by hobo sapiens (893427)
        Interesting post...

        Agreed, the Boeing engineers for this project may have no need to know what happens, but you never know...might that data prove useful for other applications of the material?

        I am no engineer (software engineer doesn't count, I know), but I'd think you'd want to test things to failure, of course where practical (as in not with a new bridge or building). If for no other reason than you have to learn all kinds of interesting things from breaking things, no?

        Maybe that notion falls apart (pun
        • by LWATCDR (28044) on Wednesday June 27, 2007 @04:13PM (#19667699) Homepage Journal
          Well Aircraft unlike computers are only operated by trained professionals.
          Since you can not make the wing infinitely strong you you put operating limits in it.
          One "neat" trick they use involves airspeed. When you start pulling Gs your stall speed goes up. Once a wing is stalled it stops generating lift so it unloads.
          Back in the day your airspeed indicator had arcs. The green arc means that your wing will stall before it breaks.
          The Yellow arc means that yes you can break the wing if you try.
          The Red line means bad things are going to happen.
          So when flying into storms the pilot can slow the the top of the green arc and be safe.
          BTW a stall at altitude isn't a terrible thing. It is better than breaking the wing.

          With this wing it may have an all Green arc.

          As to breaking the structure to learn things. Yes but that kind of testing is expensive. If the wings of the 787 pass with a bigger than average margin then I would much rather see them do repetitive tests to see how it does with multiple over stress conditions.

          The thing about some of the composites I have dealt with is some don't fail gracefully. I have parts of aircraft deform from stress but not totally fail. In other words it will get you home but she isn't going to fly again without A LOT of work.
          I have seen carbon fiber get a good scratch in it and the next thing you know it is in a million part small parts.

          • Re: (Score:3, Funny)

            by CasperIV (1013029)

            Well Aircraft unlike computers are only operated by trained professionals.
            Yeah, but these "professionals" seem to have a higher percentage drunk then computer users. Hell, these new "flapping" carbon wings will be nothing new to them... they already thought the wings were flapping after the first two drinks.
          • by Alioth (221270) <no@spam> on Wednesday June 27, 2007 @06:34PM (#19669349) Journal
            Not quite - Va (manoevring speed) is the maximum speed at which you can make a full control deflection, and be certain of no airframe damage. Va is generally below the end of the green arc. (It also varies with weight. Va increases as weight increases).
    • Since this seems like such a new concept (please correct me if I'm wrong; I don't follow plane technology too much), it would just seem prudent to try bending the wings until they break... how can they make accurate judgments and calculations without knowing exactly how much stress the wings can take before snapping?

      Not only that, you don't want to just take one data point. You need to break a number of them to get a good sample.

      Is it obvious how much I like breaking crap?

    • by secPM_MS (1081961) on Wednesday June 27, 2007 @03:43PM (#19667281)
      There is no need to do so. As you bend the wings enough you are going to loose lift. You need to test to a good safety factor. The testing would be very expensive. You would want the thing heavily instrumented. The amount of mechanical energy would be very large and you would have to clean the mess up afterwards.

      My doctorate is in Mechanical Engineering - Materials, in this case fracture mechanics. The fact that the wing is so strong suggests that it may be being over-designed. My graduate structures professor, who worked on the 747, point out that airplanes are designed for what might be called simultaneous mode failures -- there is no point in having the wings significantly stronger than the fuselage, as once the fuselage breaks the wings don't do you any good, you have just been carrying too much material in the wings. The same is true for all sub-systems. Hence, you have to do a very exhaustive analysis of the expected situations and make sure that all of them are appropriately covered, then you add a safety factor.

      Typically, fatigue cracking has been the limiting factor in aircraft structures, and has caused numerous crashes. With the experience that has been gained in military programs, we should now know enough to use these composites properly.

      • by pyrbrand (939860) on Wednesday June 27, 2007 @04:11PM (#19667679)
        Haven't you learned anything from Mythbusters? Since when do we not test things just because we don't need to know the answer? Get Jamie and Adam on it and the build crew will clean up the mess!
      • by timeOday (582209) on Wednesday June 27, 2007 @04:18PM (#19667765)

        Typically, fatigue cracking has been the limiting factor in aircraft structures, and has caused numerous crashes.
        That is the issue. It doesn't really matter whether the wings can bend until they touch when they are brand new. What matters is whether they will hold up after billions of tiny deflections, especially if there is a defect deep inside or as they get chipped, etc.
      • by joggle (594025) on Wednesday June 27, 2007 @04:31PM (#19668001) Homepage Journal
        I agree. When Boeing broke the wing of a previous jet (I think it predated the 777) they nearly broke the crane used to bend the wing. It's not only expensive to perform tests like this but they also risk breaking very expensive equipment. As others have pointed out, the wing will lose lift as it bends back so there isn't a situation where the wing could break in flight (unless there's a collision of course). The additional risks of composites aren't their initial strength anyway. This is well understood and can be modeled accurately. The problem is testing for proper construction (checking whether the fibers are fully saturated with epoxy, etc.). There's also risks with storing fuel within a composite structure. Should the fuel come into contact with the structure the epoxy will dissolve over time, weakening until failure.
      • by Anthonares (466582) <kendal30@@@yahoo...com> on Wednesday June 27, 2007 @04:50PM (#19668207) Homepage
        Composites are significantly different from metal structures in that their primary failure modes are not fatigue related microfractures, but a phenomenon called delamination in which static and dynamic loading can cause the layers of alternating orientation fibers to separate. It could very well be that in order to design a wing that was not susceptible to delamination, the wing turned out to be incredibly flexible.

        It sounds as if Boeing uses a "factor of safety" of 1.5, where the maximum anticipated load is multiplied by the factor of safety to determine the design strength of the wing. The factor of safety is calculated based on the earliest failure mode of the part, so it could simply be that other failure modes than wing deformation and buckling (as seen in the youtube video) are what determines the factor of safety with this new carbon fiber wing.
      • by Solandri (704621) on Wednesday June 27, 2007 @05:03PM (#19668371)

        The fact that the wing is so strong suggests that it may be being over-designed.
        It's probably not be overdesigned per se. Composites tend to exhibit much more strain (deflection under stress) than traditional materials. So a lot of times, the maximum deflection becomes the prevailing design criteria, not the maximum sustainable load. Most likely, the specifications for how much the wing is allowed to deflect under normal load is a more stringent criteria than how much load the wing can support without breaking. So they have to add more material to reduce the deflection, which adds strength as a side effect. (They could probably put additional stringers inside or switch to a sandwich structure to gain stiffness without additional material, but that could complicate fuel capacity and inspections.)

        The first time this was really driven home to me was in undergraduate school in '88. A classmate was working on a portable carbon-fiber bridge project for the Army. It had to support the weight of a main battle tank crossing it. In the full-scale test demo, the general overseeing the project commented that you'd get one and only one tank crew to cross the bridge. He felt that after the other tank crews saw how much the bridge flexed, there was no way they'd want to drive on it.

    • Re: (Score:3, Informative)

      by DerekLyons (302214)
      You are correct - testing is critical. But TFA does not make entirely clear that it is dicussing two different tests, one practical and one theoretical.
      1. The first, practical, test is now complete - the wing has been tested (stressed) beyond the design limits thus proving it meets the safety standards. Thus the wing, and by extension the technology, is proven and reasonably safe to proceed to flight testing.
      2. The second, theoretical, test is under consideration - stressing the wing even furt
    • Re: (Score:3, Interesting)

      by jd (1658)
      On the one hand, testing is expensive. On the other, many aircraft flaws were a result of errors in design assumptions. You obviously can think of new tests forever, but they need to stop when the value of additional testing is exceeded by any risks caused from a lack.

      Personally, I'd be in favour of much more testing. Yes, the wings are more flexible, but is that necessarily a good thing? A Boeing is not in the same league as the round-the-world-nonstop aircraft, where wing flexibility has been paramount.

  • Why (not)? (Score:5, Interesting)

    by borizz (1023175) on Wednesday June 27, 2007 @03:31PM (#19667063)
    You could, instead of downright trying to see how much it will take, try to get it up to 200% (or something, I'm not an aerospace engineer) and see for how long it can hold up to extremes like that. Might be more valuable data. Maybe someone more in the know can elaborate.
    • Well... (Score:5, Interesting)

      by StressGuy (472374) on Wednesday June 27, 2007 @03:45PM (#19667305)
      The actual requirement from Title 14, Code of Federal Regulations, Part 25, Subpart C, paragraph 303 is where ultimate load definition comes from:

      Unless otherwise specified, a factor of safety of 1.5 must be applied to the prescribed limit load which are considered external loads on the structure. When a loading condition is prescribed in terms of ultimate loads, a factor of safety need not be applied unless otherwise specified

      The three second requirement comes out of paragraph 305(b):

      (b) The structure must be able to support ultimate loads without failure for at least 3 seconds. However, when proof of strength is shown by dynamic tests simulating actual load conditions, the 3-second limit does not apply. Static tests conducted to ultimate load must include the ultimate deflections and ultimate deformation induced by the loading. When analytical methods are used to show compliance with the ultimate load strength requirements, it must be shown that--
      (1) The effects of deformation are not significant;
      (2) The deformations involved are fully accounted for in the analysis; or
      (3) The methods and assumptions used are sufficient to cover the effects of these deformations.


      If our intrepid engineers manage to test to 200% for 3 second, then somebody is going to come along and say, "let's see if we can make the wings lighter"

      Good thing or bad thing?....depends upon your point of view I guess.

      As it turns out, validating airframe structures with respect to FAA airworthiness requirements is kinda what I do for a living.
  • The 787 (Score:4, Funny)

    by kannibul (534777) on Wednesday June 27, 2007 @03:31PM (#19667071)
    The 787 will be the envy of "tuner" kidz everywhere with it's carbon fiber wings.

    If only one could find a 4ft diameter chrome exhaust tip...

    • Re: (Score:3, Funny)

      by Jeff DeMaagd (2015)
      To be truly "tuner", the exhaust tip needs to be at least twice the diameter as the actual exhaust. Just to make it look fast.
  • by powerpants (1030280) * on Wednesday June 27, 2007 @03:32PM (#19667087)
    Pull them back, let them go, and... BOEINNNNG!
  • by Titoxd (1116095)
    Of course, having the wings be flexible is a good thing, but the real important part here is that they are made of carbon fiber. Carbon fiber is much less dense than metal, which reduces the weight of the plane. If the surface area of the wings is held constant, then fuel consumption can be reduced significantly, as the downward pull of gravity is shrunk as well.
    • Re: (Score:3, Informative)

      by pclminion (145572)

      If the surface area of the wings is held constant, then fuel consumption can be reduced significantly, as the downward pull of gravity is shrunk as well.

      It also means they can change the angle of the wing to something less aggressive, since less air needs to be displaced to maintain adequate lift (because, as you say, the plane is lighter). If they didn't do that, the plane would actually have to fly slower in order to maintain a constant altitude.

  • by chill (34294) on Wednesday June 27, 2007 @03:36PM (#19667163) Journal
    If any article screams out for a Slashdot poll, this one is it.

    1. Chicken out and don't break 'em
    2. See how far they go and post it to YouTube
    3. Orinthop mode! Pull 'em back and let 'em flap!
    4. Cowboy Neal
  • by ajenteks (943860) on Wednesday June 27, 2007 @03:37PM (#19667171)
    Airbus: Care for some metal wings?
    Boeing Client: No, thank you, I take them flexible, like my women.
  • by N3WBI3 (595976) on Wednesday June 27, 2007 @03:38PM (#19667181) Homepage
    Does it really matter if, because of how they are bent, you lose lift?
    • What? (Score:5, Informative)

      by msauve (701917) on Wednesday June 27, 2007 @03:54PM (#19667443)
      The engineers at Boeing are smart enough to design the wing for optimal performance under normal conditions. That includes whatever wing bending occurs under nominal conditions.

      If the aircraft is experiencing extreme conditions which are bending the wing excessively, then you _want_ to lose lift, rather than stress the wing and airframe more. Kind of like how sailors change to smaller sails during storms.
    • Re: (Score:3, Interesting)

      by tgatliff (311583)
      Well, if they can reach a 10G loading limit, that could mean the 787 just might make a great aerobatic aircraft as well.

      I mean who wouldnt want to see the 787 doing aerobatics at the next air show. I would definitely pay a ticket to see this. Maybe they could even get old Tex Johnston to fly it as well as he has some experience here... :-)
    • Re: (Score:3, Insightful)

      by Hoi Polloi (522990)
      If they are so flexible does this mean they could ditch ailerons and go back to the ancient days of flying and bring back wing warping?
    • Re: (Score:3, Interesting)

      by tompaulco (629533)
      Yeah. Lose lift, plus have two big engines generating thrust way above the center of mass of the aircraft and more than likely too much to compensate with the elevator, so the plane would pretty much nose over.
      It's great that the wings can flex that much, but I hope it still requires just as much force to bend them 10 degrees out of normal as it currently does with a metal wing.
  • by TheWoozle (984500) on Wednesday June 27, 2007 @03:38PM (#19667187)
    ...as long as they post a video of it on their website!
  • by YojimboJango (978350) on Wednesday June 27, 2007 @03:39PM (#19667195)
    Am I going to be the first person here to think these engineers sound like they're just having way too much fun with this?

    Also I wonder what would break first, the wing, or the connection to the plane. I'm expecting the video to hit the internet in about a week.
  • If they don't break, ensure they break in some way! ;-)

    Seriously though, that idea isn't useful only for entertainment and cool effects, it is useful to know the tipping point, what boundaries they're actually working with, and not just to see if it does or does not work. And as they so often tell there -- the only way to know for sure is to test it in the real world on a non-scale model!
  • by peacefinder (469349) <alan.dewitt@gm[ ].com ['ail' in gap]> on Wednesday June 27, 2007 @03:40PM (#19667211) Journal
    "They have come a long way from even just a year ago."

    The linked video may have been uploded about a year ago, but it cites as its source a PBS production from 1995. (Which, incidentally, is discussing an entirely different airplane, the 777.)
  • Errors in post? (Score:3, Informative)

    by Bomarc (306716) on Wednesday June 27, 2007 @03:40PM (#19667227) Homepage
    Anyone notice that the "year ago" was a video of "Boeing 777 Wing Ultimate Load Test"

    Anyone notice that the date on the file is 1/14/1995?

    The implication that this was a 787 wing in test a year ago - is in error....

  • by G4from128k (686170) on Wednesday June 27, 2007 @03:41PM (#19667233)
    Thin flexible wings date back to the Boeing B-47. Up until this plane appeared in 1947, planes tended to have thick rigid wing structures. Advances in aeronautics, fluid dynamics, and structure design enabled engineers to create thin flexible swept wings that offered lower drag at high speed without flutter or breakage. The wings of B-47 (and B-52) were so floppy, they needed outrigger wheels to keep the wings from dragging on the ground during landings and take-offs.
  • Don't break it (Score:5, Insightful)

    by Broken scope (973885) on Wednesday June 27, 2007 @03:41PM (#19667239) Homepage
    A bit of wisdom from a Retired Boeing exec who I forgot the name of.

    The story was about one of the earlier Boeing's, they had stressed the wing to like 10 times any theoretical force that could be possibly placed on it during a rather publicized testing of its strength. They test folks were all about trying to break it.

    During the process of doing this an exec asked them what they were doing. "Breaking the wing" they replied.
    The exec said No, stop the testing.

    Why? the testers asked.
    Because the headline won't read ,

    "Boeing wing breaks at 40 times the stress encountered during possible flight conditions",

    Instead it will read

    "New wing of new Boeing Jet Breaks".

    Please note Its been awhile since I heard that story, but I think the point is pretty clear.
  • by fishthegeek (943099) on Wednesday June 27, 2007 @03:42PM (#19667259) Journal
    This would make one heck of a good video for Youtube would if it's done right. I would be very interested to watch the test accompanied by the 1812 overture with the wings snapping in a spectacular fashion just as the drums hit! Oh, and add two squirrels and a cat fighting to the video. And while you're at it add lightsabers and two chicks kissing. Now that would make a good video!
  • 747 Wing Flex (Score:4, Interesting)

    by Lev13than (581686) on Wednesday June 27, 2007 @03:42PM (#19667265) Homepage
    Airplane wings flex quite a bit more than you'd expect. Airliners.net has a great head-on shot of a 747 taking off [airliners.net] that shows the wingtips flexed up higher than the fuselage. Kinda freaky looking.
  • by Taimat (944976) on Wednesday June 27, 2007 @03:57PM (#19667489)
    Ladies and Gentlemen, this is your captain speaking... If you take a look out the windows on the left side of the plane, you will notice our right wing....
  • by Thagg (9904) <thadbeier@gmail.com> on Wednesday June 27, 2007 @04:01PM (#19667541) Journal
    The fact that the 787 is a "plastic airplane" will get a lot of play, and having wings that bend, potentially to the point that they will tough, is just the most obvious and mediagenic manifestation of that. But it is just the tip of the iceberg of the innovations.

    1) Yes, it's almost completely carbon fiber. This means that the plane can (and is) lighter, so it will be more fuel efficient. Also, it's easy to make complex curved shapes, so the wings and fuselage are slightly more aerodynamic. Because carbon fiber structures are so strong, the windows can be larger, and the plane can be pressurized to a lower altitude (it will be pressurized to 6000' instead of the typical 8000' of today's fleet). There is no corrosion, and little worry about fatigue in composites.

    2) The plane is not built in Seattle, although that's where the final assembly takes place. All of the building takes place in multiple facilities around the globe, each producing parts to Boeing's plans. These parts will "snap together" in the Everett plant. The first 787 is being assembled right now, and will roll out on 7/8/7 (just over a week from now.) Apparently the left wing was off by 2 thousands of an inch or so, the right wing was absolutely perfect. Boeing converted three 747's to be gigantic cargo transporters to move all the parts from around the world to Everett.

    3) The plane has almost completely electric, without the high-pressure pneumatic systems that older planes had. In particular, the AC systems are electric. This will be somewhat more efficient, and safer.

    4) The plan for certification of the plane is borderline insane. The final assembly started a couple of weeks ago, and the plane will be rolled out in a week, the first flight will be in a couple of months, and the first delivery will be in Q2 2008. This is a tiny fraction of the time this process required on previous airplanes -- maybe 1/4 the time of the 777 and even less than that of the latest Airbus. This would be remarkable, even if the plane wasn't revolutionary in every other way, too!

    5) Aviation Week and Space Technology visited the final assembly line recently, and were surprised to find that it was almost an empty building. That's not because they weren't ready -- that's because there are almost no tools needed to assemble the plane. They snap together the pieces, install the landing gear, and roll it down the building on its gear installing the various subassemblies. Boeing intends to assemble a plane every three days once they get going, a remarkable and unprecedented schedule.

    Anyway -- there are so many revolutions in this airplane that I would have thought it was a scam if it was any other company than Boeing. It remains to be seen if they can meet their goals, but so far things are going remarkably according to the plan they laid out a few years ago.

    Thad
    • Re: (Score:3, Interesting)

      by e2d2 (115622)
      Also, one of the most anticipated features of this new aircraft is it's range, unprecedented in a mid-size airliner. The quoted figure is 8500nm for the 787-9 model. That's insane! And in today's world where fossil fuel costs keep rising, gains like this make airlines drool.
  • by Anonymous Coward on Wednesday June 27, 2007 @04:05PM (#19667601)
    I am an aerospace engineer, however i am a propulsion engineer and not a structures guy. Ill try to add some light on the subject.

    First off the requirement is a 1.5 saftey factor, ie 1.5 times greater load on the wings then they would encounter during operations. In the past, wings were always broken on new planes. Not only is this fun (engineers do like breaking things, its true), but it provides very useful data to validate your computer models and test methodology. Not often does an engineer get to shatter such an expensive and large article! Predicting before hand when a wing will snap can be very useful on future airplane designs to optimize the structural layout. Remember, any load past the 1.5 saftey factor just means you made the wing too strong, and thus it has extra weight!

    Now a days, the structural FEMs (finite element models) and load definitions from CFD (Computational Fluid Dynamics) have become so good, that its not necessary to validate the tools. They have been validated before, and there is a high level of confidence. Someone mentioned above me that these wings were different since they are composite, but in fact commercial airplanes have had composites in the wings for a long time. The military has been making nearly all composite airplanes for even longer.

    The A380 from Airbus ran into trouble a few years ago, as they designed the wing for 1.5 load factor, but on testing it only made it to 1.48. Hence they had to add extra weight and strengthen it. But being that they aimed for 1.5 and got to 1.48 shows you how accurate the tools have become.

    There might also be a cost element in this decision. I believe Boeing could potentially use that model for some other purpose, whether it be passenger escape tests, wing fuel fire tests, wing fatigue tests, or maybe even just for a model to sit in a hanger somewhere and generate PR. Personally, im hoping to see a great video on YouTube of those wings splintering into pieces!
  • by goodEvans (112958) <devans&airatlanta,ie> on Wednesday June 27, 2007 @04:43PM (#19668149) Homepage
    Take a look here [flightstory.net]. There was a 1.5 inch difference in the diameter of the Section 41 (nose and cockpit) and the Section 43 (forward fuselage, where the forward entry door is). The parts are made in Wichita and Charleston, SC. They have managed to join them now, but the job was "challenging".

    Now I am an engineer at an aircraft MRO. Once these things hit more than 15 years old, there are going to be a million problems with this fuselage. Carbon fibre is a very different beast to aluminium, or even fibreglass. For one, the carbon is a conductor of electricity, which can lead to galvanic corrosion (the circumferential frames are still aluminium, there are still metallic fasteners going through the skin to attach them). Also, repairs are going to be an absolute bitch.

    Twice in the last month, we have had to fix large holes in the side of aircraft due to trucks driving into the side of them. These incidents happened at outstations (where there were no major repair facilities) and we had to send out a small team to assess and repair the damage. In both instances these were done by a repair engineer, inspector and a couple of sheet metal workers in a couple of days. They took a sheet of metal, an air compressor and a bucket of rivets.

    Currently, composites are used on a number of components on almost all aircraft. Invariably they are removable components, like flight control surfaces, or fairings. In order to repair them, they are usually removed from the aircraft and repaired in a composites shop, where temperature and humidity can be controlled - preferably in an autoclave.

    Now, how the hell is anyone going to remove a fuselage section to drag it into a shop?
    • wrong and wrong (Score:3, Interesting)

      by YesIAmAScript (886271)
      Actually, there was not a different in diameter. It's just that one of the cylinders hadn't been supported properly for a couple days and became oblate. It was still the right size, just not the right shape. So they jacked it back into shape and connected it. It wasn't difficult.

      Your comments about holes in planes ("ramp rash") are also off base. Boeing has two patch kits, one which can be applied in a very short time, the other which takes something like 36 hours to cure. Boeing has shown to the airlines t
  • by Solokron (198043) on Wednesday June 27, 2007 @08:29PM (#19670283)
    Here are new photos of the first 787 before paint.

    787 Photos [airliners.net]
  • DUH (Score:3, Funny)

    by hurfy (735314) on Wednesday June 27, 2007 @09:00PM (#19670605)
    What is the point of having all that cool test equipment and cameras if you can't break stuff ?!?

    hehe, 30 years later i still remember a trip to the local power station that had the test equipment for powerlines and stuff. They crushed a large ceramic insulator til it blew up. Took some insane amount of pressure like 20000 psi. Quite spectacular. They had a rig for pulling apart a powerline too, we would have killed for that test ;)
  • Carbin Fiber flex? (Score:3, Interesting)

    by stickyc (38756) on Wednesday June 27, 2007 @09:28PM (#19670809) Homepage
    I was under the impression that carbon fiber was actually renowned for being inflexible and tending to shatter, rather than deform (at least from my experience with motorcycle fairings and carbon fiber rims). Is there a less-rigid mix of CF? If so, why is it not used in racing products?

It seems that more and more mathematicians are using a new, high level language named "research student".

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