A center wing box design flaw has forced Boeing to redesign a critical section of the 787, program sources tell FlightBlogger, due to the potential for premature buckling in the structural spars.
Stiffeners will be affixed to restore structural integrity to the spars on the existing center wing boxes, which are manufactured by Fuji Heavy Industries in Japan.
When approached for comment, Boeing reiterated the statement it released yesterday regarding design changes:
“It is normal during the development of a new airplane to discover the need for design enhancements. We are working with our partners to address the need for design changes in some areas. While these changes are not good for final assembly because they are dealing with traveled work at this time, the design changes are not the sole pacing item.”
During the initial development phase of the center wing box, the structural spars were designed to the appropriate width to support the required structural loads.
The original design for the center wing box was changed when the weight of the Dreamliner began to increase. The structural spars, which are made of composite, were reduced in width as a weight saving measure.
Boeing and Fuji Heavy Industries manufactured composite test pieces to demonstrate the structural capabilities of the spars. Findings indicated that the composite spars were buckling prematurely compared to metal spars of the same width.
A source familiar with the situation tells FlightBlogger that Boeing became aware of the issue around the time of the July 8, 2007 roll out of Dreamliner One.
"Similar design changes happened in 777, but the difference is that 787 was so far away from weight target that many weight reduction ideas were adopted even though there was high risk due to lack to supporting test data or manufacturing experience," says a source familiar with the situation.
As a result, Boeing is incorporating an interim solution to the existing six center wing boxes under final assembly.
The stiffeners intended for the center wing box have already been delivered to the Boeing Factory in Everett and are being prepared for installation on the four airframes under assembly. Two additional center fuselage sections, which include the center wing box, are being prepared for final assembly at Global Aeronautica in Charleston, SC.
The center wing box is made from both traditional metals and composite. The new stiffeners will be composite and aluminum and matched to complementary areas of the structure.
FlightBlogger has been told that a redesigned center wing box will likely be ready for the first production aircraft, Airplane Seven, which is expected to be delivered to Japan’s All Nippon Airways in 2009.
The center wing box is the structural core of the aircraft representing an intersecting node between the wings, Section 43 on the forward end, Section 46 and main landing gear well at the rear, and Section 44 which caps the center wing box and completes the center fuselage section.
The first public indications of a wing box problem came from Boeing’s largest 787 customer, International Lease Finance Corporation chairman Steven Udvar-Hazy reportedly told a JPMorgan analyst earlier in the week that he does not expect the first delivery to occur until the third quarter of 2009 as a result of structural design changes that are needed to the center wing box, implying an additional six-month program delay.
on March 20, 2008 7:06 PM | Reply
Wow. So how many more of these kind of delays can we see?
on March 20, 2008 7:18 PM | Reply
Nice reporting Jon!
What can I say? Surprise Surpise!
This news are beyond the organizational, poor logistics planning and management problems. Now we're talking about design problems and negligence (FAA/EASA are you listening?) and they had been hiding the thruth since the very beginning! (stock markets, are u listening?)
on March 21, 2008 1:05 AM | Reply
The similarities to the Airbus experience are emerging. Don't admit problems until there is a pile-up. Next, management shake-up, reassessment, and reluctant "descent into humility." Followed by a more rational transparency. Publicly admitting things are a mess no doubt undermines private penalty negotiations.
on March 21, 2008 3:56 AM | Reply
Excellent report Jon. First hand info as usual.
Well, I thought that the 787 was going to fly soon... but this problem seems a little bit critical. I don't wanna see this aircraft having structural failure in middle flight!
on March 21, 2008 5:17 AM | Reply
This is a classic example of pushing the design envelope too far. Question is...
What else have they pared down to the absolute minimum?
And no..
I'm not a Boeing Weight Engineer
on March 21, 2008 2:06 PM | Reply
The 787 is design that moved into many uncertain technologies: a fly-by-wire system whose architecture has not been proven in development projects and researches before being incorporated into the design, an awkward fly-by-wire system that still uses the yoke and not a sidestic, an electrical anti-ice system that obviously can not be supported because it has never passed though sufficient testing, a wing composite structure that is not vaible, a carbon fuselage that will never be possible to be produced at high rates, an aircraft size which is surely wrong, because the trend is to use larger airplanes to reduce the number of flights, for instance, the A380 and finaly, the worse, a highly integrated airplane with a partnership organization that evidently Boeing is yunable to manage dequately.
In summary, Boeing is trapped, and the 787 will impose huge lossess to the Company and morevover, it will definetely cost the leadership of the aviation industry for the next decades.
Airbus is dominating the industry from now and on...
on March 24, 2008 3:54 PM | Reply
So much for travelled work and lack of fasteners! Trying to bite too much too quickly! I hope that FAA and EASA check this thing with a microscope before it's too late.
Rudder hardovers, engine rollbacks, exploding fuel tanks, flightcontrol oscillations...... hmmm
on March 25, 2008 10:27 AM | Reply
And, knowing about all this for several years did not prevent the internal forces from creating the 'potemkin' event. Oh, on second thought, any who did raise concerns was drummed out or beaten down.
Only a marketing-focused company would think about pushing to where engineers fear to tread. How did engineering get in such a fix?
on March 25, 2008 11:25 AM | Reply
Can't say I am surprised by problems arising from such a bold design. I just can't wrap my mind around what were the Boeing engineers thinking when they decided the delivery date for the Dreamliner (the FAA people were surely laughing when they heard). One would think that Boeing had taken note of the A380 scenario and decided on a more conservative delivery date. And I don't think this will be the last delay of the 787.
on March 25, 2008 11:26 AM | Reply
Can't say I am surprised by problems arising from such a bold design. I just can't wrap my mind around what were the Boeing engineers thinking when they decided the delivery date for the Dreamliner (the FAA people were surely laughing when they heard). One would think that Boeing had taken note of the A380 scenario and decided on a more conservative delivery date. I don't think we've seen the last of delays for the 787 either.
on March 25, 2008 11:27 AM | Reply
Can't say I am surprised by problems arising from such a bold design. I just can't wrap my mind around what were the Boeing engineers thinking when they decided the delivery date for the Dreamliner (the FAA people were surely laughing when they heard). One would think that Boeing had taken note of the A380 scenario and decided on a more conservative delivery date. I don't think we've seen the last of delays for the 787 either.
on March 25, 2008 4:32 PM | Reply
I concur there is a need for a Management shake-up at the Boeing Co. The Executive management team did not heed lessons learned from Airbus. There is a need for Boeing to free itself of incompetent and incapable people who call themselves leaders with the sole intent of raiding the corporate coffers of profits for personal gain and thinking that aircraft manufacture is like selling post-it notes. However, this is a new design, new and cutting edge technology for a commercial aircraft. Nothing will be perfect but Boeing engineers created the 747 that became the standard in the industry for decades. The 787 will work and in time will be an amazing aircraft that will drive immense change in the industry. The question is will it's induction into service be well managed?
on March 25, 2008 7:22 PM | Reply
This is not at all comparable to the A380 fiasco.
Sorry to say, it is much more widespread in its scope.
How anyone could "shave" the wingbox wiithout a full stress analysis first I find incomprehensible.
on March 26, 2008 6:03 AM | Reply
"...many weight reduction ideas were adopted even though there was high risk due to lack to supporting test data or manufacturing experience"
This situation has occurred because certain people prefer to take shortcuts to achieve unreasonable targets. The same happens with costs. This is a management and culture weakness. There is saying in England: beware of saving pennies that will cost you pounds in the long run. Some people were rewarded their share of pennies just to cost the company and the industry so many millions of pounds in the long run.
Lesson: never take shortcuts in aviation, do it right.
on March 26, 2008 7:10 AM | Reply
This aircraft will not get off the ground before 2010..Its gonna cost Boeing far more than A-380 to Airbus.. If A-350 takes off in 2013 as scheduled, Dreamliner is dead and in consequence ,Boeing is dead..Airbus will rule the sky...
on March 26, 2008 1:46 PM | Reply
Its all gone very hush hush with the B777 Heathrow incident...unless I have missed an update from Boeing.
The BA rumour club is even suggesting Mr Brown had something to-do with it ...come on lets have an update please Mr Boeing.
on March 27, 2008 7:07 AM | Reply
Captain X from a.net has made may claims which although initally denigrated have proved frighteningly accurate, very much like some of Jons' reports.
His latest utterance that the wing has to be re-designed is horrendous, but the re-design of the wing box could mean that the attachment points are now in the wrong place.
Pray that he is wrong this time.
The financial consequences are too much to comprehend.
Boeing stock is not on my "must buy" list right now
on March 27, 2008 7:20 AM | Reply
As Barnes Wallis once said "You can't cheat nature. She will find you out". It's a shame the bean counters and Rollo Freelunches aren't aware of this.
on March 27, 2008 5:08 PM | Reply
Am I reading this press-report wrong???
After testing to validate analysis engineers found some allowables/calculations were unconservative. A fix has been implemented to increase the buckling resistence.
Remember that buckling is not a failure, a buckled web will continu to support higher loads.
on March 27, 2008 6:03 PM | Reply
@ikkeman:
Well, it may continue to support loads, but its integrity is weakened and you can rest assured that a plane facing such an incident will be grounded immediately with the spars to be replaced. And that's not something you can do in a nightly maintenance timeframe.
The problem is, as mentioned earlier, that the management of many companies is driven by the rules of the stock market alone. The time when an engineer's feedback was valued are long gone, unfortunately. Today, the management tells you when a product is ready -- problem is, this won't work in the aircraft industry, and that's a lesson Boeing has yet to learn. It is even more frustrating since Airbus has set an example of where this road will take you, and Boeing wasn't able/willing to take the right actions.
I don't see the 787 flying before 2010, and the more time is lost, the more likely it is that the A350 will gain market shares... provided Airbus has learned its lesson.
on April 9, 2008 8:04 AM | Reply
Free Kick to Airbus.
How much weight can you save and still fly with a safety margin?
on January 4, 2010 6:03 PM | Reply
wow....message to Boeing -Work harder- also whens the 797 coming out?