RBC Heim Bearings: Reliable PMA Solutions for Maintaining the Boeing 757-200

The company RBC Bearings Incorporated primarily focuses on creating bearings and mechanical linkages for markets that demand highly-engineered and regulated products, with their acquired Heim Bearings portfolio featuring much of the company’s bearings for aviation use. More than being basic approved aircraft hardware solutions, some of these bearings conform to strict Boeing Aircraft Company (BAC) specifications, which approve select high-quality components to be installed on new-build aircraft. This blog will examine how RBC Heim Bearings’ BAC-standard offerings are made to support renowned aircraft like the Boeing 757-200, covering the basics of how a company like them gains approval, in addition to some of the particular bearing products they make.

How Does a Company Gain Approval to Produce Aerospace Replacement Parts?

Parts Manufacturer Approval (PMA) is a combined design and production approval issued by the Federal Aviation Administration (FAA), granting a manufacturer the right to produce and sell certain replacement or modification parts. Essentially, the product must be equal in performance to or better than the item it is meant to replace from an original equipment manufacturer (OEM), validated in this through one of three pathways:

Identicality via Licensing Agreement: The new manufacturer has a formal agreement with the OEM to use their original design data.
Identicality without Licensing: A company proves through detailed blueprints and audits that their part is physically and chemically identical to the OEM part.
Test and Computation: An applicant can prove through engineering analysis, laboratory tests, and reverse engineering that their part meets all airworthiness and performance requirements.

In any case, PMA parts are backed by comprehensive evidence about everything from their material composition to their characteristics under testing, along with the manufacturer’s demonstrable ability to achieve repeatable results. For crucial pieces of hardware like bearings, details like load ratings, hardness and heat treatment, and their exact dimensional tolerances are carefully reviewed, seeing as their failure can have great consequences on flight controls and engines.

BAC Standards and Their Relation to PMA

BAC standards are developed by Boeing to maintain complete authority over the uniformity of materials, manufacturing processes, and installation practices for the parts employed in its programs. To this end, Boeing has specified that items delivered for new-production applications need their primary identifier to be the BAC part number and cannot carry any FAA-PMA markings, as they are seen as an aftermarket regulatory designation.

Alongside meeting design benchmarks and general industry standards, manufacturers like RBC Heim Bearings that seek BAC recognition must also follow some more stringent approvals.

Using D1-4426 Approved Process Sources

While the FAA permits PMA holders to use any properly certified and audited AS9100 special process provider, Boeing maintains a list of approved vendors to perform heat treatment, chemical processing, plating, and other such finishing tasks for BAC items. A manufacturer may hold FAA PMA approval and still be prohibited from claiming BAC compliance if its sub-tier processors are not listed on the D1-4426 database.

Appearing on the Qualified Products List (QPL)

Many BAC bearings are designated as QPL parts, meaning Boeing has evaluated representative samples from a manufacturer and issued them formal qualification documentation based on good findings. As with the previous requirement, a PMA holder may legally sell replacement parts to operators without QPL status, but it is required for a component to be identified and marketed as a BAC standard part.

Aligning with Boeing Process Specifications (PSs)

Boeing publishes detailed PSs regarding how components are to be assembled and installed. For example, BAC 5435 defines approved installation practices for bearings, including fit conditions, alignment considerations, and handling requirements. BAC manufacturers will have to demonstrate that their parts are suited to these Boeing-specific procedures in addition to basic fit, form, and function mandates.

A Look at RBC Heim Bearings’ BAC-Standard Parts for the Boeing 757

The Boeing 757 series revolutionized the industry throughout their time in production, all being built with efficiency and the ability to accommodate repeated service cycles. Among the variants in this family, the Boeing 757-200 is still a well-loved configuration for heavy-cycle cargo operations and the occasional passenger flight. As these aircraft age and continue to see use, a steady supply of components are needed to sustain maintenance, repair, and overhaul activities. Furthermore, replacement bearings utilized in control systems and structural interfaces are particularly important to keep consistent, as mismatching can introduce performance inconsistencies or accelerate wear.

RBC Heim Bearings leverages their engineering expertise to manufacture a few specialized bearings that satisfy the dual rigor of PMA and Boeing’s BAC standards. For keeping the B757-200 fleet airworthy in particular, some notable part numbers they produce include:

Part Number BACB10W7T: This spherical bearing serves well in high-load applications where angular misalignment is expected. Its wide race design increases its load-bearing surface area, while the self-lubricating liner supports controlled motion without manual greasing.
Part Number BACB10P: You will find this airframe ball bearing in primary and secondary flight control linkages that connect the pilot’s inputs to the elevators or ailerons. The “P” in their BAC part number indicates an intermediate duty rating, engineered to handle the cyclic stresses of thousands of flight hours while keeping their precision for responsive handling.
Part Number BACB10V: While also an airframe ball bearing, the “V” in this part number identifies a self-aligning bearing made of Corrosion Resistant Stainless Steel (CRES). Often, they are employed in areas like landing gear door mechanisms or wing leading-edge slat tracks prone to structural flexing or moisture.

Procure What You Need from RBC Heim Bearings on Supersonic Aviation Parts

In all, RBC Heim Bearings is one of the names on the narrow list of manufacturers trusted to create standardized Boeing aircraft parts. Outside of obligation, using BAC products can also provide operators with more flexibility in their budget and procurement options, as they are available from multiple trustworthy entities. This is especially true when sourcing for aging aircraft fleets like B757s, where direct manufacturer support can be limited.

If you are interested in purchasing a particular bearing like part number BACB10W7T or other BAC components from approved manufacturers, we have you covered on Supersonic Aviation Parts. On this ASAP Semiconductor platform, thousands of PMA-approved components and other industry-standard offerings are offered to serve as a one-stop source for aircraft operators and maintenance providers. Each item on our database is listed with accurate details and will be shipped out with complete documentation, supporting transparency and traceability at every step of the purchasing process. To learn more about our commitments to quality and how we can serve you, connect with our expert team via phone or email today.