To make the 737-9 / 737-10 (what ever you want to call it) more attractive, how feasible would it be for Boeing to make a new composite wing? This could also allow the ability to use slightly taller main landing gear to fit those bigger engines and give better runway rotation clearance. With the 787 and 777X program, the knowledge and manufacturing skills of composite wings is getting better by the day at Boeing. A new wing would obviously require new fatigue re-certification, but the market size for this aircraft would definitely cover that.
Wing area and span being equal, what would be a rough estimate of weight savings for a 737 composite wing vs. the current 737 wing?
Also, another note:
For the longer range 737 missions (737-9 on a trans-atlantic route) where a raked wingtip would be more efficient over a winglet, could Boeing develop a 777X style folding wingtip? Maintain the group III gate fit, but give the aircraft a bit more wingspan.
A 737-9 (or 737-10) with a composite wing and folding tips would be a killer aircraft.
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- richcam427
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Re: 737 Composite wing possibility?
The 737 won't get a composite wing (or fuselage) until it's replacement comes around. Don't quote me on this, but I believe there are only certain differences that allow an aircraft to remain on a previous type certificate, which was one of the selling points of the NG and MAX to previous operators. I believe that a composite wing would void that.
Re: 737 Composite wing possibility?
Also, I believe weight savings on composites don't scale well to smaller airframes; a composite 737 wing would not weigh that much less than the current wing.
Re: 737 Composite wing possibility?
77west wrote:Also, I believe weight savings on composites don't scale well to smaller airframes; a composite 737 wing would not weigh that much less than the current wing.
Therein lies the problem.
Composites save a certain percentage of weight. So, for example using fictitious numbers, if the composite weight reduction gets you 10% less wing weight, then a 777 wing that weighs 10 kilograms now weighs 9. A 737 wing that weighed 4 kilograms now weighs... 3.6. And while 10% is always 10%, it ceases to be "significant." For this reason, the MRJ abandoned the use of composites for primary structure even AFTER they'd done all the engineering on it.
So it's not a "big deal," at least not big enough to justify the OUTRAGEOUS COST of engineering an all new wing. And yes, it would have to be all new... you can't simply replace metal parts with identical composite ones and call it a day.
Also, a new wing would likely render the 737 un-certifiable in its current form. The aircraft has several other obsolete design features that would cease to be grandfathered in, as they say.
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- richcam427
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Re: 737 Composite wing possibility?
I'm assuming that most of the R&D and engineering work was done with the 787. That's why it was so important, not only for the plane itself as the 767 replacement but for the future as well. That technology will most likely make its way down to the 737 replacement, including the use of composites and FBW, just as those technologies were up-scaled from the A320 to the A330/A340, A380, and A350.
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- kurtverbose
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Re: 737 Composite wing possibility?
A big factor with making composites work with narrowbodies is the production rate. Laying up, baking and curing 20 high value wings a month is a very different proposition to 120 lower margin wings.
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- Revelation
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Re: 737 Composite wing possibility?
richcam427 wrote:I'm assuming that most of the R&D and engineering work was done with the 787. That's why it was so important, not only for the plane itself as the 767 replacement but for the future as well. That technology will most likely make its way down to the 737 replacement, including the use of composites and FBW, just as those technologies were up-scaled from the A320 to the A330/A340, A380, and A350.
I think one should be a bit leery of this. I think the 'stretches are easier than shrinks' rule applies here. Also while the missions of 737 and 767 are more similar than they were in the past, the 787 still has more than twice the range and twice the weight and twice the thrust.
I'm sure a lot of knowledge will transfer, but also a lot will have to be revised or even re-invented. Keep in mind the 787 is early 2000s tech. A lot has changed since.
Re: 737 Composite wing possibility?
I would still venture a guess that a folding wingtip on a long range 737 could be a viable option.
Re: 737 Composite wing possibility?
Sure, foldable wingtips is good option if your gate space isn't limited. But, it increases wing stress and weight from hydraulic actuators and associated plumbings. Folding wingtips also increases wing bending. You need stronger structures >>> weight increases.
Besides, you need longer range to recoup from fuel efficiency what has been lost from increased structural weight. That makes it unattractive, cause it's thirstier on shorter routes. I would still think the operators want the flexibility to deploy 737 on any routes on their structures, and not constrained to some subtypes that need more gate spaces and efficient on shorter routes, especially for operators who deploy 737 on segments less than 2 hours.
I think if the efficiency is achievable with less dramatic solutions like scimitar winglets, it's easier to put scimitars instead.
Besides, you need longer range to recoup from fuel efficiency what has been lost from increased structural weight. That makes it unattractive, cause it's thirstier on shorter routes. I would still think the operators want the flexibility to deploy 737 on any routes on their structures, and not constrained to some subtypes that need more gate spaces and efficient on shorter routes, especially for operators who deploy 737 on segments less than 2 hours.
I think if the efficiency is achievable with less dramatic solutions like scimitar winglets, it's easier to put scimitars instead.