StandardAero’s APU test cell,at Maryville, Tennessee StandardAero
StandardAero’s APU test cell, at Maryville, Tennessee, viewed from the test cell control room. The T-62T-40-5 APU pictured in the test cell is one of more than 35 platforms the company maintains.

Test Equipment Access Increasingly Tied To OEM Partnerships

OEMs restrict access to testing equipment to grow aftermarket revenues, motivating MRO providers to form partnerships with them.

Printed headline: Trickier Testing

In 2013, Delta Air Lines decided to bring repairs of a Boeing 737-800 APU starter generator in-house. To do that, it approached Honeywell, the component OEM and service provider, with a request for all the requisite tooling and test equipment. According to information made available about the case on the 2017 Mechanical Maintenance Conference’s website, while Honeywell supplied the requested tooling, it did not make the Resolver test panel assembly available, despite repeated requests from Delta over the past four years. To date, the airline and the vendor have yet to resolve the conflict.

Delta declined an interview request. “This is not something we’re going to weigh in on,” says Michael Thomas, Delta Air Lines corporate communications manager. Honeywell, however, claims that a resolution is actively being pursued.

“Honeywell is committed to support all its airline customers. We had been aware of this request and had reached out to Delta to assist [with] and address their requirements,” says Steven Brecken, director of global aerospace media relations for Honeywell Aerospace. “We are still waiting on a response from Delta and look forward to resolving any issues they have with maintaining their Honeywell starter/generator and support equipment.”

MTU Aero Engines

MTU Aero Engines has established risk- and revenue-sharing partnerships with OEMs for aftermarket services. That gives the company access to intellectual property- protected repair licenses and test equipment.


But the fact is, this is not an isolated case. Testing equipment is critical to the repair process, and indications are that more component and system OEMs will either withhold it altogether or vastly limit its use by their airline customers or independent OEMs.

“If a manufacturer can avoid making the maintenance instructions or recommended tooling and equipment available, it might,” says Sarah McLeod, executive director of the Aeronautical Repair Station Association (ARSA). “If the tools and equipment are not generally made available, it is often because there is a cost for making it available or constructing it.”

Jonathan Berger, managing director of the New York-based Alton Aviation Consultancy, reports that limiting the use of manufacturer component testing equipment is part of the long-running, continuing effort among OEMs to capture more aftermarket services.

Berger points out that years ago, maintenance manuals were very complete. “One of the strategies used by the OEMs to grow their aftermarket support business was to reduce the repairs and inspection criteria, which had been [previously] spelled out in those manuals,” he says. “That was the low-hanging fruit. Now, the OEMs are starting to see similar opportunities with test equipment.”

He also notes that in cases where the OEM will provide test equipment, there could be strings attached. For example, a customer might be told the equipment cannot be used to test a parts manufacturer approval (PMA) or designated engineering representative (DER) part; or the OEM might make testing devices available only if the components being tested will be used for the customer’s fleet and not for any third-party work the customer provides.

“These are fairly new strategies and tactics the OEMs are using, but they are also up for negotiation,” he says. “The larger the MRO or airline, the more leverage it will likely have when negotiating for the manufacturer’s test equipment.”

In some cases, Berger explains, there are alternatives to OEM-sourced test equipment as long as the user can provide the data to demonstrate OEM equivalence. “But that will be easier to demonstrate with mechanical components, and less so when software is involved,” he says. “That’s because the software used by the components and the testing equipment is often OEM-proprietary. This will become more common, especially with the automatic dependent surveillance-broadcast “Out” modifications.”

Asked if there are cases in which OEM test equipment could be applicable to PMA components, Berger says it would be if the PMA part is strictly OEM-equivalent. But he warns that if the PMA product is a modification or an enhancement of the OEM part, the OEM test device may not be usable.

What does appear to be a key factor with testing-equipment access is some kind of partnership or alliance between an airline or independently operated MRO and an OEM. As ARSA’s McLeod notes, today’s repair stations are either “partners” with the OEM or “independent.” “If you are the latter, it is more or less understood that you will need to develop your own maintenance manuals, tooling and equipment,” she cautions. “It makes sense that if you are a partner, the OEM maintenance data, tools and equipment would be part of the arrangement.”

Such partnerships will likely become increasingly essential for engine MROs, as the next generation of turbine engines enters service.


StandardAero’s APU test cell, at Maryville, Tennessee, viewed from the test cell control room. The T-62T-40-5 APU pictured in the test cell is one of more than 35 platforms the company maintains.

Uwe Zachau, head of industrial engineering at MTU Maintenance in Germany, sees increased OEM coverage for next-generation engines. “To access IP [intellectual property]-protected repair licenses and testing equipment, as well as MRO volume, the independent maintenance service providers will need to intensify their cooperation with OEMs,” he says. “MTU Maintenance has adapted its strategy to this market situation,” he adds.

Zachau explains that the company, with a maintenance portfolio of more than 30 turbine engines, has established relationships with OEMs through MTU Aero Engines’ risk- and revenue-sharing partnerships, with participation in aftermarket networks for the PW1100G-JM, the GEnx and the GP7200, with the GE9X to be added in the future. Cooperative arrangements are also in place with Lufthansa Technik and airlines such as China Southern.

Reed Chase, general manager for Empire Aerospace in Hayden, Idaho, agrees that obtaining test equipment for certain components from the OEMs can be difficult in the absence of some kind of an alliance. “This has been true for any of the flight-control systems’ internal components, because the OEMs want to control who is able to repair and certify the repairs,” says Chase, whose company specializes in the ATR family of regional airliners.

Empire Aerospace, he points out, has the capability to repair the flight-control systems’ internal components in-house, but because they are not able to obtain the test equipment needed to certify the repairs, the components have to be shipped back to the OEMs.  To do otherwise, he reports, the MRO would have to enter into some type of licensing or partnership agreement. In fact, Reed reports that a formal MRO relationship with the airframe OEM is under consideration.

“Right now, we are in the preliminary stages of talks with the ATR to be part of the ATR MRO network. Should an agreement be reached, it would be our first such partnership with an OEM,” he notes.

“Partnerships with OEMs will become even more essential for access to the testing schemes and equipment from the OEMs, especially as the testing protocol evolves and becomes more complex,” says Clinton Kent, vice president for components, at StandardAero Services in Cincinnati. The MRO, Kent reports, has subcontractor relationships with all the major engine OEMs and has a maintenance portfolio of more than 35 different platforms.  Among the company’s major revenue generators are the CFM56, V2500, PW4000 and the CF6 families. “We have worked directly with OEMs to get test equipment, when needed, as a subcontractor to the OEMs on components we repair.”

Kent stresses that test equipment, even under MRO-OEM partnership arrangements, is never free. “Testing equipment is a major investment, not only in procurement costs but also for any upgrades and modifications required as engine families evolve,” he explains. “At StandardAero Services, we will purchase test equipment if a good business case can be made for doing it.”

As part of the decision-making process, says Kent, the company develops a forecast to determine the amount of repair revenue that could be generated on a specific engine type or component. That, in turn, is weighed against the acquisition cost of the test equipment and the length of time it will take to pay the investment back. Once a purchase decision is made, the test equipment is sourced from either the OEM or an OEM-designated supplier.

StandardAero Services, Kent says, has purchased everything from test cells for full-up engine testing, to smaller units for components such as fuel control test systems, or crusher testing for detecting air leaks. 

Kent stresses that the vast majority of testing equipment purchased by StandardAero Services is engine- and OEM-specific.  But he says in most cases, that does not mean having to acquire a totally new testing system whenever the OEM upgrades an engine family.

“As engine types are enhanced or modified, the testing changes,” he explains. “In many cases, all that is required is some hardware and software modifications. Also, when there are changes involving specific components, we work with the OEM—which will provide us with the requirements we have to follow—prior to making the investment in modifying the test equipment.”

Testing equipment might be more available from the OEMs for legacy components, particularly where engines are concerned. “The engine OEMs want to focus on their new platforms, but they realize that there are still a lot of older engines in service that need to be supported,” says Kent. “Here, again, is where they will turn to their MRO partners for support, which would make the testing equipment that much more available, some of which can be applied to multiple older parts.

Empire Aerospace’s Chase adds that OEMs are also more likely to provide test equipment if there are “a lot of” surplus parts on the market, and the trend is away from aircraft and systems where those parts apply. “In those cases, the test equipment will be much more readily available to an MRO,” he says. c

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