HOME  |  NEWS  |  BLOGS  |  MESSAGES  |  FEATURES  |  VIDEOS  |  WEBINARS  |  INDUSTRIES  |  FOCUS ON FUNDAMENTALS
  |  REGISTER  |  LOGIN  |  HELP
Blogs
Blog

Composite Aircraft Repair Advances

NO RATINGS
Page 1 / 2 Next >
View Comments: Oldest First|Newest First|Threaded View
Page 1/2  >  >>
Beth Stackpole
User Rank
Blogger
Certification a no-brainer
Beth Stackpole   12/6/2011 6:45:17 AM
NO RATINGS
I would think it goes without saying that there should be new standards and certifications for technicians charged with the responsibility for vetting out and orchestrating the fix of composite structures in need of repair. Composite materials are very different that what's required to repair metal and steel structures. I don't know why we need a government report to tell us an heavy investment in training and skills building is necessary!

ScotCan
User Rank
Platinum
Composite Aircraft Repair Advances
ScotCan   12/6/2011 8:39:15 AM
NO RATINGS
@Beth.The government gets involved because the private sector tends to gloss over problems in order to maintain market share. That being said too much government involvement stifles progress. The Bombardier decision is more likely based around deHavilland's experience over the years where their tough aircraft stood up to some primitive operating conditions...dings and dents being the standard operating experience. Also the flight cycle time for the Dash 8 on the west coast averages 58 minutes which is rough on a structure where fatigue is concerned. Aluminum-Lithium is a difficult material to work with but (again) Fleet Industries in Ontario has had long experience in building (and repairing) such structures.It will be interesting to see where Bombardier goes with this since the C series is a big change from the smaller aircraft built previously.

Dave Palmer
User Rank
Platinum
Aluminum-lithium alloys
Dave Palmer   12/6/2011 12:49:55 PM
NO RATINGS
@Ann: The title of this article seems to be out of step with its contents, to say the least.  Obviously Bombardier doesn't think composite aircraft repair is advancing enough to justify using composites in the CSeries fuselage.

Which aluminum-lithium alloys is Bombardier using? There was an article on this website a few months ago about Alcoa's new third-generation aluminum-lithium alloys, which were developed cooperatively with Bombardier.

 

Rob Spiegel
User Rank
Blogger
Is this just a transition period?
Rob Spiegel   12/6/2011 2:29:56 PM
NO RATINGS
Interesting story, Ann.

I'm curious as to whether this is a transition time for composite materials or whether there is something intrinsic to composites that makes detection of problems and repair more difficult for composites than it is for more conventional materials.

Ann R. Thryft
User Rank
Blogger
Re: Composite Aircraft Repair Advances
Ann R. Thryft   12/6/2011 2:45:31 PM
NO RATINGS

I think the answer is a bit of both. Beth, the industry apparently has been working on solving this problem along with the FAA. At least, that's what they all tell us. But it's quite difficult to find out any details. And that's where ScotCan's point comes in. As the report delineates, industry has been extremely secretive regarding the details about their materials--the type of details which must be well known for determining when and how to repair--in the name of trade secrets. 


Ann R. Thryft
User Rank
Blogger
Re: Is this just a transition period?
Ann R. Thryft   12/6/2011 2:49:46 PM
NO RATINGS
Rob, that's the $64,000 question. I think the answer here is also 'both." Composites are definitely moving forward in aerospace, as shown by all the aircraft makers using them in greater amounts. And detection of at least certain types of damage is difficult, but apparently not impossible. 

Alexander Wolfe
User Rank
Blogger
Re: Composite Aircraft Repair Advances
Alexander Wolfe   12/6/2011 2:50:14 PM
NO RATINGS
I'm impressed by the breadth of your recent coverage on composites, Ann. I'm wondering if you see new standards emerging out of the FAA as regards composites repair, or will we see industry-standard practices come into play first, which will become de facto methodologies for both repair and recycling?

Charles Murray
User Rank
Blogger
Beyond material strength
Charles Murray   12/6/2011 10:12:44 PM
NO RATINGS
This is a classic example of the need to beware that what looks good on paper may not always be so. As design engineers, we are often trained to consider matters of stress and strain -- bending, shear, torsional capacity, etc. But here we have a situation where the composite is apparently appropriate in matters of material strength, but not in matters of maintenance. Obviously, maintenance is a huge consideration for aircraft. In 1979, an American Airlines flight leaving Chicago O'Hare crashed, killing 271 people, after a design flaw left the engine pylon vulnerable to maintenance damage.

Dave Palmer
User Rank
Platinum
Re: Beyond material strength
Dave Palmer   12/7/2011 10:23:19 AM
NO RATINGS
@Charles: You're absolutely right; materials selection involves many considerations besides the material's response to stress and strain -- which can be complicated enough, since the material may respond very differently at different temperatures and strain rates, and its properties may be different in different directions.  But how a given material will perform in your application also depends on its location in the galvanic series, among other things. Cost and manufacturability are always major concerns, too. Then there are externalities such as recyclability and end-of-life issues, sustainability and lifecycle emissions, etc.  And -- although I may be somewhat biased in this regard! -- this is why having a good materials engineer is a necessity.

Ann R. Thryft
User Rank
Blogger
Re: Composite Aircraft Repair Advances
Ann R. Thryft   12/7/2011 12:54:27 PM
NO RATINGS

Thanks, Alex. The news just keeps coming out on this subject. Regarding standards, that's a really good question. One of the key critiques in the GAO report was the point that you can't base repair standards and best practices for composites on the same ones that were created for metal. There are too many differences across the board, and making the same assumptions or using the same templates would be ineffective and dangerous. That may be another reason why we're not hearing much yet about the details of repair whens and hows. I suspect it's a WIP.


Page 1/2  >  >>
Partner Zone
More Blogs
Take a look at the top 20 US undergraduate engineering programs. Then tell us -- did your school make the cut?
Engineers at the University of San Diego’s Jacobs School of Engineering have designed biobatteries on commercial tattoo paper, with an anode and cathode screen-printed on and modified to harvest energy from lactate in a person’s sweat.
A London-based company has added some sweetness to the versatility of the 3D printing market with a printer designed solely to print candy and confections.
Programs to boost domestic manufacturing combined with technological advances are bringing production back to the US.
Google's Project Tango is in its second iteration, this time taking the form of a tablet. Join us as we unravel the new goodies that Google has packed into the Project Tango Tablet.
Design News Webinar Series
7/23/2014 11:00 a.m. California / 2:00 p.m. New York
7/17/2014 11:00 a.m. California / 2:00 p.m. New York
6/25/2014 11:00 a.m. California / 2:00 p.m. New York
5/13/2014 10:00 a.m. California / 1:00 p.m. New York / 6:00 p.m. London
Quick Poll
The Continuing Education Center offers engineers an entirely new way to get the education they need to formulate next-generation solutions.
Sep 8 - 12, Get Ready for the New Internet: IPv6
SEMESTERS: 1  |  2  |  3  |  4  |  5  |  6


Focus on Fundamentals consists of 45-minute on-line classes that cover a host of technologies. You learn without leaving the comfort of your desk. All classes are taught by subject-matter experts and all are archived. So if you can't attend live, attend at your convenience.
Next Class: September 30 - October 2
Sponsored by Altera
Learn More   |   Login   |   Archived Classes
Twitter Feed
Design News Twitter Feed
Like Us on Facebook

Sponsored Content

Technology Marketplace

Copyright © 2014 UBM Canon, A UBM company, All rights reserved. Privacy Policy | Terms of Service