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Boeing postpones 787 first flight

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posted on Jun, 25 2009 @ 11:11 AM
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Originally posted by RichardPrice
There is another blog reporting that the delamination occurred during the wing bend test, at just 120% of maximum design load. Not sure on how to take that, Im dismissing it as an unfounded rumour at hte moment.


Rumours of skin stringer debonding... as opposed to delamination.


Which would agree with:

www.flightglobal.com...



Late May
Boeing experiences the first signs of trouble on the static airframe. During that test, the wings of ZY997 were flexed and the strain measurements on the stringer caps were reading higher than predicted.

Previously, on April 21st, Boeing conducted the limit load test which saw the wings deflected over 17-feet and an equivalent of 120-130% of maximum load.

"We went in and did some inspections and saw a number of things indicative of what the strain gauges were saying," said Scott Fancher, vice president and general manager of the 787 program, said on yesterday's teleconference, implying that the test had left visible damage to the structure during the late May testing.




posted on Jun, 25 2009 @ 11:13 AM
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Originally posted by deckard83

Originally posted by kilcoo316
First of all they have to correct the models that gave the wrong result in the first place!!

That is no easy task in itself.
(why do you think Airbus have been keeping their mouth shut)


Will this mean the faulty models have caused design problems elsewhere?


Hence why I said:


It is quite obvious something has went badly wrong in their Finite Element work. Be that design allowables or poor methodologies. How significant might that turn out to be?




[edit on 25/6/09 by kilcoo316]



posted on Jun, 25 2009 @ 11:17 AM
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Kilcoo, are you saying that the A400M is suffering from this same problem but Airbus have kept quiet about it. Is this the issue they were covering up when they scapegoated the engines?

If that is the case, are both Boeing and Airbus basing their designs on a common flawed formula regarding the design of high aspect ratio carbonfibre wings for large transport aircraft?

That would be even more serious than any of us thought, or have I misread you?



posted on Jun, 25 2009 @ 11:18 AM
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Originally posted by FredT
Its going to hurt short term. But they still have a time advantage on the A350 so I dont think too many will risk loosing thier place in line. Because A350's inital production run at 500+ orders probably has very few slots open, someone wanting to buy would have to wait a long time to get their airframes. Yes they can offer A330's or even dump them but its crap shoot IMHO because the A350 has yet to begin testing etc and thier schedule looks pretty agressive as well.


The A350 is no longer the enemy.

Can Boeing deliver the contracted performance to the airlines?
Can Boeing deliver a safe aircraft?
Can boeing deliver the contracted maintenance schedules to the airlines?

The MD-11 couldn't meet the promises McDonnell Douglas made... look what happened to them.



Originally posted by FredT
Its a fault of thier own making. They pushed an over agressive and optimistic design, build, and test profile for the aircraft and had no margin for any errors. Compund this with an entirely new techology for Boeing and this was bound to happen.

The flip side is that the all composite 777 follow they will have to build at some point should be a smoother proposition


Indeed.

If they are in the financial shape to press on and take advantage of this knowledge acquired the hard way.



posted on Jun, 25 2009 @ 11:25 AM
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Originally posted by waynos
Kilcoo, are you saying that the A400M is suffering from this same problem but Airbus have kept quiet about it.


The A400M wing has a large number of problems.

Some of which are related to the dimensional fidelity of the components, some of which are related to the weight (and hence mechanical performance*) of the components.

There are other aerodynamic issues as well.

*basically Airbus were more conservative than Boeing, so while the thing is safe to fly, the weight is prohibitive.


E-Beam curing and carbon nanofibres in composite resins cannot come quick enough for the aerospace industry. Until they do come, I'm of the opinion that using composites for large principal structural elements is a mistake.





If that is the case, are both Boeing and Airbus basing their designs on a common flawed formula regarding the design of high aspect ratio carbonfibre wings for large transport aircraft?


It will not be the formulae that are wrong, rather it will be the allowables/specifications used as inputs and goals.


[edit on 25/6/09 by kilcoo316]



posted on Jun, 25 2009 @ 11:26 AM
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Originally posted by kilcoo316

Originally posted by RichardPrice
There is another blog reporting that the delamination occurred during the wing bend test, at just 120% of maximum design load. Not sure on how to take that, Im dismissing it as an unfounded rumour at hte moment.


Rumours of skin stringer debonding... as opposed to delamination.


Which would agree with:

www.flightglobal.com...


In there is also this choice quote:



Boeing confirms that small areas of the wing structure separated or "disbonded" from the wing skin, though declined to specify exactly where. Sources directly familiar with the situation say the shifting tension load from the stringer to fastener head also caused damage on the structure.


Theres the delamination.



posted on Jun, 26 2009 @ 05:57 AM
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Qantas cancels 15 Boeing 787 orders, defers 15 others
www.flightglobal.com...

This is probably good news of sorts for boeing as it should allow boeing to reduce the delays for there other customers.



posted on Jul, 5 2009 @ 03:48 AM
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I know about an advanced imaging technique that was used on the composite panels.

This imaging technique demonstrated potential problems that conventional x-ray imaging & the like could not show.

I was told that some of the Boeing engineers were very concerned about what they saw.


[edit on 5-7-2009 by Sam60]

[edit on 5-7-2009 by Sam60]

[edit on 5-7-2009 by Sam60]



posted on Jul, 5 2009 @ 04:13 AM
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from something i`ve read - there is very very serious concern of failure below limit load as well - the structure isn`t working as desingned - and i would be VERY surprised if the 787 flies this year



posted on Jul, 6 2009 @ 08:20 AM
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Aviation Week will be running a story today citing industry analysts who are skepctical that the current wingbox related issues will take less than 18 months to resolve fully.



posted on Jul, 6 2009 @ 08:50 AM
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Hi, lots of good info here, since I can't afford a subscription to "Aviation Leaks and Space Secrets" I feel out of the loop!

Since this is the most active (currently) B787 thread, I wonder if I could drop a question that's bugging me?

WHY have Boeing changed their model suffixes to single digits, starting with the 787?

AND, how will they differentiate customer's versions (i.e., the AAL version is a -223, while a CAL version is -224, etc.)??

I see no logic in the change...and their website isn't helpful.



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