The fielding of commercial aircraft making much more use of composites and other advanced materials in airframes and engines is spurring increased spending on research and development among maintenance, repair and overhaul (MRO) providers. 

Spirit AeroSystems has introduced a new out-of-autoclave repair process for composite propulsion system components. “Generally, the repair techniques and materials used for the out-of-autoclave process apply to all propulsion-family products that Spirit manufactures, but we have found that the most imminent need for this technology is the thrust reverser inner wall,” says John Welch, the Wichita-based company’s chief scientist-global customer support and services. The repair was granted FAA approval as an alternative method of compliance in September, following 18 months of testing and data substantiation. 

“The goal was to develop a composite repair technology that will deliver the same capability for mission performance and restorative strength that would be achieved using an autoclave,” says Welch. “Also, the out-of-autoclave process benefits those customers who lack an autoclave, which is a very high-cost piece of equipment.” 

The new repair can be performed in-house by Spirit or made available as a kit to approved MROs, he says. The kit can reduce the repair time to as little as two days, compared to 14 days with an autoclave. Welch attributes this, in part, to the fact the repair process does not require complete disassembly of the thrust reverser’s inner-wall structure—and that Spirit performs all preprocessing of the kit, including cutting, orientation and layup of each material layer. 

In addition to recently introduced repair schemes, future technologies are being actively researched. “We have four or five projects going on right now that focus on ending repetitive repair issues—mostly on nacelles,” says Jim Epperson, Spirit’s senior engineering manager, global customer support and services. “Our R&D is also being applied to the evolving major airframe composite structures of the new-generation jets. In that regard, we are finding that if a certain repair technology applies to one type of component, it can likely apply to such major structures as fuselages and wings.” 

StandardAero Component Services is shifting its focus toward composite parts repair technology¸ says Director of Engineering Tim Mathis. The ratio of metal to composite engine parts repaired by the company is 80:20, but that could reach a 50/50 split within a decade, he says.

“The challenge is how do we get ready to repair the new composite engine parts that we don’t even know about yet,” says Mathis. “That means addressing issues involving equipment and technology; as well as those for composite parts inspections, layup, and the more sophisticated machining methods that will be required.” 

“From what we are seeing with our partners, new research and development is coming in leaps and bounds—mainly with engine shops and composite airframe MROs,” says Josh Goring, business development director for AJW Technique in Montreal. He advises that as original equipment manufacturers tighten their grip on new airframe and engine aftermarket support, third-party MROs need to increase their R&D budgets. 

“If third-party MROs are going to retain their piece of the aftermarket support pie, more R&D will be needed for out-of-the-box thinking and reverse engineering, especially as the next-generation platforms require much higher proficiencies in avionic and electrical understanding,” he notes.

The full version of this story appears in the MRO Edition dated Dec. 7-20, 2015.