Location: China
Challenge: An engine repair and overhaul facility in China requested Eaton’s help to repair a duct support assembly with unusual lug damage.
Solution: We restored extremely tight tolerances on the Inconel-cast lug using a variety of repair techniques, including welding, precision machining and heat treating.
Results: We completed repair, testing and certification processes and returned the successfully repaired duct to our customer within 15 days.
Eaton’s advanced repair capabilities provide cost-effective solution for unusually damaged duct assembly
Background
Eaton’s high-quality duct, tube and hose repair services provide a cost-saving option to keep airplanes flying reliably and include innovative solutions for damaged components previously considered unrepairable. Our global repair stations are certified and equipped to work on more than 8,000 part numbers found on most commercial and military engines and airframes.
In addition to standard repairs addressed in component maintenance manuals, our highly skilled and experienced repair teams can perform complex repairs requiring advanced levels of engineering, manufacturing and materials expertise. Our advanced capabilities also enable us to repair non-Eaton products and quickly complete repairs, along with required certifications, to meet our customers’ accelerated schedules.
Challenge
An engine repair and overhaul facility in China approached Eaton with a special-order repair opportunity involving a damaged duct support assembly. Technical repair instructions were developed by the facility’s airline customer; however, the process required engineering and repair capabilities not typically offered by MRO service providers.
The damage consisted of wear on an inner mounting lug surface. The thickness of the lug, which was cast from Inconel 718, along with exceedingly tight tolerances involved in returning the duct to a structurally acceptable condition made the repair especially complex. Repairing Inconel 718 also requires heat-treat cycles that are uncommon for most ducts and can damage non-Inconel ducting materials.
Solution
To prepare for the repair process, our team built special fixtures and tooling to keep parts aligned correctly during repair work. They also removed two flexible joints from the duct that could be damaged by heat treatments.
After removing the bushings, new material was welded onto the worn surface to restore the lug’s original dimensions. Once lug holes were drilled to extremely tight tolerances, the final three ten-thousandths of an inch were removed manually to achieve correct diameters. After precisely aligning the lug holes, our repair experts heat-treated the duct, installed new bushings and welded it back together with flexible joints.
Result
Eaton’s team performed a series of tests on the repaired duct to confirm its airworthiness and returned it to the engine repair facility. Our reliable, economical repair solution made it possible for our customer to use the duct in their overhaul project rather than having to buy a costly new spare and scrapping the duct. Despite the repair complexity, our experts were able to complete the entire process within a 15-day turnaround time.
When repairs are not addressed in component maintenance manuals or other instructions, Eaton is certified to develop and perform Designated Engineering Representative repairs that comply with the U.S. Federal Aviation Administration’s airworthiness approval process. Eaton repairs also comply with certification standards issued by the European Union Aviation Safety Agency and the Civil Aviation Administration of China.
