More Dreamliner Problems
“HAIRLINE CRACKS” FOUND IN WINGS OF NEXT GENERATION JET … “More Dreamliner pYou must Subscribe or log in to read the rest of this content.
“HAIRLINE CRACKS” FOUND IN WINGS OF NEXT GENERATION JET … “More Dreamliner pYou must Subscribe or log in to read the rest of this content.
17 comments
It isn’t SC’s fault, but don’t let that stop you from bashing Boeing coming here.
Just like an odd-lotter, he’s always fighting the tape. The mark of a born loser.
This is going to get interesting, once composites start cracking they usually develop a pattern, since the majority of the skin on this aircraft is composite this could be a huge problem because it’s not likely a single part that’s going to be affected.
Aerospace engineer Sic Willie gives us the latest technical information from his scientific mind in the article. However, composites have been used in aircraft for many years. (See SR-71) It is hardly a brand new technology. So Sic Willie, what NDT was used to locate these “cracks”? Where EXACTLY are they located? Etc.
Boeing said the 787 cracks occurred in shear ties on wing ribs, and will take one to two weeks to inspect and fix.
Wing ribs run parallel to the fuselage of the plane. The ties, made of aluminum, hold the rib to the skin of the wing and will be replaced with an aluminum part.
“If we find an affected area, we’ll correct the issue by trimming out the area and applying a fabricated piece in its place,” Alder said.
Boeing declined to discuss the manufacturing change that led to the problem. Mitsubishi wasn’t immediately available to comment.
“However, composites have been used in aircraft for many years. (See SR-71) It is hardly a brand new technology.”
The SR-71 was 85% Titanium & 15% Carbon….my guess is that the Dreamliner is no where near that for cost reasons(and gov’t projects don’t suffer those problems for the most part if the votes are there).
Anyone happen to know EXACTLY what the composite is for the Dreamliner? A quick google only tells me it’s “carbon-plastic” which obviously would have no where near the structural integrity of titanium & carbon.(and Boeing might very well not release the composite details for competitive reasons)
Being a motorcycle aficionado I always watch carbon fiber structures with interest in the motorcycle world. Ducati just recently gave up on their attempt. Britten did it successfully, but not before suffering a structural failure that hurt one of his riders and his methods would be difficult to replicate in production.
Of course, there’s also carbon wheels…but they aren’t ready for general use either…just open class racing under controlled conditions.
I remain very skeptical of the long term durability of carbon composites and designing for daily air travel is a major step beyond even high level auto racing.
The SR-71 was a maintenance nightmare…and ostensibly used better materials than Boeing is trying to utilize now. Maybe technology has progressed to make it possible…or maybe they just over reached like Ducati.
Only time will tell.
Don’t disagree. I also think you are correct that Boeing is not going to hand out proprietary info. My point of using the SR-71 was to illustrate that the idea of using composites (regardless of their composition) is not a “new” idea. You could even say that fiberglass, e.g. boats and Corvettes, is use of composites.
The cracks were caused by shear ties on wing ribs made out of aluminum. The flaw was in the shear ties on the wing ribs, not in the composite material.
Apparently there is both an issue with the shear ties and the composite according to this article:
http://seattletimes.com/html/businesstechnology/2023076224_787wingcrackxml.html
It seems the shear ties are causing hairline cracks in the composite, but if I read the article right it seems like they are ongoing issue with hairline cracks outside of the shear tie issue as well.
edit: “they” to “there”
I read the article in your link carefully.
I did not see the reference to ongoing problems with hairline cracks in the 787. They mentioned Airbus, but those were fatigue cracks after many years in service.
The hairline cracks that the article is focused on, are caused not by fatigue, but by stress induced by over-tightening of the fasteners to the shear ties on wing ribs made out of aluminum without the use of manufacturing fillers. This indicates it is not a failure of the composite to meet its rated strength, but a problem due to over-tightening without use of manufacturing fillers. The rated stress acceptable by the composite was exceeded by failure to use manufacturing fillers, not by flight, or normal stress.
The change in the process seems to be changing the requirement to use manufacturing fillers when the fasteners are tightened.
Once the fasteners have been tightened – the “over-tightened” fasteners have already caused the hairline cracks in the composite. They pointed out that the biggest problem was in the second rib, but that it may also occur on other ribs as well.
Of course, any composite that has these cracks has to be trimmed off, and replaced (presumably with the same composite).
So the conversations in this topic concerning the composition of the composites are focused on a red herring.
Yes, you are correct-it was Airbus. Thank you!
*TBG “doesn’t hear the whistle” and piles on…*
http://www.google.com/hostednews/afp/article/ALeqM5hayUCP9CQf5nDKOYjzm78Rv_GzOg?docId=f1770f70-06ed-439a-a45c-6b346d0d27c9&hl=en
As a primary Delta traveler, CNSYD has flown on numerous MD-88s as they are the “work horse” of the Delta fleet. Back when I was “Medallion” status I was usually upgraded to 1st class. If you are close enough you can hear all the conversation of the pilots and ground crew prior to the door being closed. Plenty of times there are conversations about spurious warning signals that almost always turn out to be in error. Since you are on the ground, it is obviously easy to go look and check/test where the alleged problem is. It was a very rare occasion if something had to be “fixed”. So on a plane series that started service in 1980, there are still “problems”. Also notice the use of words like “reported” in the 787 article.
Hey guys: what if one of these planes crashed filled w/ people…and thousands of South Carolinas lose their jobs…and Nikki Haley is blamed…Now you can bet FITS would get his Rocks Off on that…
Clue: a product in the development process is not Perfect…and ironing out wrinkles does not make FITS look smart. FITS’ praying for disaster, so he can use it to attack his political and social enemies, makes FITS look like a piece of $#!* though….
A 787 flying across the Pacific had to make an emergency landing today in Hawaii. Not a good day for Boeing.
Will sits up at night praying for one of these to crash so he can blame Nikki Haley. Will don’t fret, I saw a BMW in a crash last night. You can start writing your article blaming that on Carroll Campbell. How dare these people try to bring industry into SC.