Composite Structure
Boeing feels composites ar
e the right material choice for the 787.
a major element of fuselage and wing design. Even with the creeping advance of composite into aircraft design, metal has still dominated — and so have the time-tested skills of machining and metalworking. But now times have changed, and in response to that change, the MRO industry, OEMs and government are pushing towards a common standards-based certification program. Their efforts are being spearheaded by the Commercial Aircraft Composite Repair Committee (CACRC). It is an OEM/airline/ MRO committee operating under the aegis of SAE International, a collaborative engineering group that collectively sets standards for the aerospace and automotive industries. The CACRC’s mandate is to reduce the cost of maintaining composite structures, through the standardization of materials, techniques and training. Hoke has been working with CACRC to help develop a composites certification process for mechanics. “Such a program might have several levels to it,” he tells Aviation Maintenance. “For instance, a Level 1 composites certification would ensure that a technician has the skills and know-how to do basic composite repairs on a number of aircraft components. As the levels go up, the amount of skill and experience required would also increase — to the point where a Level 5, for example, would indeed know how to do the most complicated 787 and A350 XWB repairs.” At this point in time, the CACRC is on track to issue a preliminary Level 1 certification standard. “When this is ready, it will be sent to SAE’s member engineers, so that they can vote on accepting the standard as proposed, or requiring further work,” says Hoke. “The process is taking time, but at least progress is being made to close the standards gap.”
The Clock is Ticking
While the CACRC works on a standard-based composite certification process, the MRO industry waits. But at least they’ve got some breathing room. The 787 is just entering service, while the first flying version of the A350 XWB is still being built. With Delta not scheduled to receive 787s until 2020, “It is going to be a while before we see these composite-heavy aircraft,” says Todd Herrington. “So yes, we do have some time to get our people up to speed, and to make any tooling changes that are required as well.” However, time is also working against the MRO industry. In the absence of a certified composites talent pool, companies have been relying on the skills of individual technicians to shoulder this work — and those technicians tend to be the kind of experienced veterans
30 Aviation Maintenance |
avm-mag.com | August / September 2012
who are approaching retirement age. “It’s a very true statement to say that the overall expertise in composites — at least from an airline MRO employee standpoint — is on the decrease,” Herrington observes. He notes that this is not the case at Delta, given its close contact with the CACRC. “As airlines divest their MRO duties to third-party MROs, there are fewer composite-capable technicians left in-house.” As well, “your MROs are only as good as your airlines are,” Herrington notes. “This is due to the fact that the airlines supervise the MROs and if you have a lack of experience at the airlines, the expertise will, in turn, decrease at the MROs.” Add the lack of a certified composites training program for new mechanics, and the old talent is not being replaced by new hires. “We are laying the foundation through the CACRC to have standards document out there, that can be used by a training group to create a program, but that is in the future,” he says. “Right now, we don’t even have a standard detailing how one would methodically go through any kind of bonded composite repair.” To put things into context, there was a time when jet engines were new to the airline industry, and MROs had to scramble to figure out how to support them. Then as now, new skills had to be learned, and new equipment and tooling added to keep up with the future. This said, the move to composites is a quantum leap in aircraft engineering. No longer do OEMs just have to cut and combine pieces of material to make aircraft. Now they have to make that material almost from scratch — just like a baker making a cake. To keep their airline clients served, MROs will have to learn their own “baking” skills. In fact, the MROs of tomorrow will have to be as adept in the art of composites creation and application as Airbus and Boeing are today. Moreover, the composites revolution won’t likely stop at the 787 and A350XWB. In fact, once this technology has proven itself through lower operating and maintenance costs, the airlines will demand as little metal as possible in its commercial airframes. And the OEMs will find ways to satisfy this demand. The day will even come when the 787 and A350 XWB will be viewed as outdated and uneconomical pioneers of aviation’s next stage, just as the 707 and DC-8 are seen today. It’s just a matter of time, flight experience, and engineering progress. For MROs wanting to survive into the future, the message is clear: Adapt to composites, or perish. Because once a revolution has gained momentum, there’s no stopping it — and the composites revolution is moving at full speed.” AM
Copyright © 2012 The Boeing Company
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