As airlines grapple with parts availability and costs, some are taking remedial action through owner-operator-produced parts (OOPP)—also known as owner- produced parts (OPP).

In actuality, OOPP could avoid the expense—and possibly long lead times—involved when ordering a specific part from an OEM or PMA source. For U.S. operators, the FAA permits a part already owned by the airline to be reproduced as a single unit, or in quantity, as a replacement part or for modification purposes, as long as it meets all requirements and characteristics of the original FAA-approved part.

The part’s owner, according to FAA regulations, must also function as the part’s producer by controlling the part’s design, along with some level of participation in its manufacturing process to assure quality control. That applies whether fabrication is done in-house or by an outside shop. The regulations also state that installation of OOPP are limited to the aircraft owned or operated by the party responsible for the production of the part. In other words, the part cannot be installed on another operator’s aircraft.

“Parts typically targeted for OOPP are Category 3 high-usage, high-cost, high-lead-time items, which are small and not safety-of-flight sensitive.” However, as Gil notes, the regulations do not prevent OOPP from being more flight-safety significant Category 2, or even Category 1 parts, although he stresses that is not the norm.

Along with reduced lead times and costs, Gil says that the advantages of OOPP are often in the form of improved reliability and greater control over supply chain resource support. “New OOPP are able to be approved and produced much quicker than a PMA part utilizing the operator’s internal approval procedures versus having to submit for PMA through the lengthy FAA approval process,” he says.

According to Patrick Markham, vice president for technical services at HEICO Corp. in Hollywood, Florida, while the majority of OOPP programs are focused on cost, time savings and availability, obsolescence factors and maintenance efficiencies are also incentives to opt for OOPP. “Cabin interior parts are great examples of OOPP, where an OEM quotes an airline ridiculously long lead times and high prices. But I have also seen airlines use OOPP to fix a maintenance problem that an OEM wasn’t interested in fixing,” he says. “Wherever the airline is highly customized or having trouble with a non-responsive OEM, that is where they will be looking for an OOPP or other solutions.”

Where to Use Them

“We worked with the customer to design and manufacture an aluminum shroud for this engine, to replace the OEM-furnished composite product, which was not as durable, serviceable and repairable as the original aluminum shroud, no longer available from Pratt & Whitney,” he says. “The composite shroud was slightly lighter, but more expensive than the aluminum part it had replaced.”

Scott Mowery, president of InTech Aerospace, says he often suggests that his customers select OOPP as an OEM alternative. The Houston-based supplier focuses on airline cabins—primarily curtains, seat covers, plastic arm caps (rests); as well as lavatory, galley and overhead bin trims.

“For some items, a customer can save as much as 75% of the OEM price for the identical part when opting for OOPP,” Mowery explains. “A good example is the cover for the arm caps. It was $65 from the OEM, but our price to the customer for an OOPP was about $20.”

Mowery also cites lead times as an OOPP advantage. For some cabin interior parts, he says, OEM lead times could range from 120 days to six months. “In fact, that is even true for current-production aircraft, because a lot of interior component manufacturers have huge lead times,” he says.

Sheffield Aerospace’s Teddy Gil cites a customer who was doing interior maintenance during an off-peak travel period and found a damaged seat panel. “OEM lead time for a small quantity was 90-plus days, so Sheffield used the established OOPP process to reverse- engineer the part—with deliveries in under four weeks at less than half the cost,” Gil says.

Craig Barton, vice president of technical services for American Airlines, reports the Ft. Worth-based carrier’s OOPP program is “across the board” in airframe, engines and components. “Interiors are a heavy user, but we do a number of one-off items, as well,” he says.

Barton points out that American’s OOPP program is authorized under its Part 121 certificate and is documented in its policy and procedure manuals. The carrier, he explains, “does not typically seek any further regulatory” approval for an OOPP unless it is part of a larger modification or change, which would require another level of authorization. “As part of the review and internal approval process, any risks inherent with each specific part are evaluated to ensure that those risks are understood and controllable,” he remarks. “We will continue to pursue OOPP as part of our supply chain strategy.”

Cape Air, a niche regional airline based in Barnstable, Massachusetts, uses a wide range of OOPP that are no longer available or reasonably supported by the OEMs of the aircraft it flies—currently 88 Cessna 402s, which are out of production, and four Britten-Norman Islanders. As Jeff Schafer, Cape Air’s managing director of technical operations explains, the twin-piston fleet is focused mostly on small communities, serving 35 destinations in the U.S. and the Caribbean.

“A few examples of those parts are door-latch assemblies, push/pull rods and fuselage frames,” says Schafer. He points out that all of the parts fabrication is outsourced. “We provide our expertise with respect to the part’s design, while the contractors do the part’s actual fabrication. The OOPP is exactly equivalent to the part we would get from the OEM, using the same materials and manufacturing processes.”

Schafer confirms that the OOPP must meet or exceed the same standards for the part as required by the OEM. “To make sure of this, we do a stress analysis of the parts, for all phases of flight,” he says. “But that’s also true of parts we get from the OEM.”

Asked about future applications of OOPP in general, Schafer argues that will depend largely on the sector of the industry involved. “Many cargo carriers are operating older, legacy fleets, so OOPP will play a significant role in their maintenance programs,” he says. “However, [it won’t be] as much with airlines that have newer fleets. It will be an evolution.”

Additive Manufacturing, 3D Printing Could Push OOPP

Emerging 3D printing and additive manufacturing could expand use of OOPP.  “As it matures, 3D printing/additive manufacturing will be a natural fit, especially in the quick-response/low-volume world of most OOPP,” says Patrick Markham of HEICO Corp.

However, Intech Aerospace’s Scott Mowery cautions that the technology is still in its infancy. “For example, the materials that interiors are made of have to comply with flammability regulations, and at this time Ultem is the only material I know of which can be used to fabricate an interior part that meets this requirement,” he says. “Still, I expect that as more materials are developed this will expand in the future.”

At Sheffield Aerospace, Teddy Gil sees 3D-printed parts becoming more competitive as the technology evolves. Sheffield, he reports, is already using the technology to build one-off parts not visible to the passengers as well as most first-article samples, to ensure proper form, fit and function prior to final tool and part production release. “This saves on initial tooling costs with improved lead times from initial concept to production.”

But American’s Craig Barton expresses mixed feelings: “Our experience, so far, is that we can just as easily make parts using more standard manufacturing techniques. I do believe that 3D printing and additive manufacturing technologies will begin to play a larger part, but they likely would not enable us to do anything we don’t already do today.”

Categorically Speaking

The FAA has classified aircraft parts into one of three categories, depending on their potential impact on safety. The criteria establishing and identifying the part categories details the level of FAA involvement in the parts-approval process, as well as the level of technical data, quality control system procedures development, and processes necessary to support fabrication of parts within each category.

Category 1 Part: A fabricated part, the failure of which could prevent continued safe flight and landing; resulting consequences could reduce safety margins, degrade performance or cause loss of capability to conduct certain flight operations.

Category 2 Part: A fabricated part, the failure of which would not prevent continued safe flight and landing, but would reduce the capability of the aircraft or the ability of the crew to cope with adverse operating conditions or subsequent failures.

Category 3 Part: A fabricated part, the failure of which would have no effect on the continued safe flight and landing of the aircraft.