Sources Sought: Non-Destructive Inspection (NDI) for On-Aircraft Bearing Liner Measurement

February 28, 2024

NCMS is assisting the Department of Defense in seeking industry or academic partners who have the capability to provide aircraft non-destructive inspection (NDI) methodologies that accurately determine polytetrafluoroethylene (PTFE) liner thickness on aircraft pitch links. This capability is needed at Fleet Readiness Center East (FRC East) in Cherry Point, NC.


Aircraft Swashplate/Pitch Assembly Overview:

Aircraft swashplate and pitch links help transfer flight control from stationary actuators to a spinning rotor head. Pitch links in each rotor attach the swashplate to a pitch horn on each arm of the rotor head. Pitch links act as a strut, pitching (twisting) the blade as it is pushed or pulled.

Each Pitch Link Assembly has a spherical, rod end bearing that accommodates rotational freedom. The bearing assembly is installed in the upper and lower rod ends. The bearing assembly consists of an outer race, liner, and spherical ball.

Liner is bonded to the inner diameter (ID) of the outer race and interfaces with the outer diameter (OD) of the spherical ball. A 0.012 inch (minimum) thick polytetrafluoroethylene (PTFE) liner is bonded to the outer race and lubricates the inner ball.

Image 1: Example Swashplate Assembly

Problem Description:

Bearing malfunctions result in exponentially rapid wear through the PTFE liner, followed by metal-to-metal contact of the bearing’s ball and race. Early stages of wear result in abnormal (but tolerable) vibrations in flight. If vibrations are detected in time (i.e., prior to metal-to-metal contact), then troubleshooting time on the ground is extensive to determine the cause of vibration as it can come from various areas. Therefore, there is an additional need to be able to quickly rule out the pitch link assembly early in the troubleshooting tree.

Current Inspection Method:

Shim stock is utilized as “go/no go” inspection. If shim stock of 0.009” thickness can be inserted, the liner is assumed to be worn to limit and bearing replacement is necessary.

Image 2: Example Bearing Assembly at Rod End

Issues with this inspection measurement technique are that bearings are most likely to be removed that are good, due to the subjectivity of the test by the maintainer and the lack of ability to accurately measure the thickness of the liner.


Solution Requirements

FRC East is seeking information regarding on aircraft NDI methodologies to accurately determine the PTFE liner thickness.  NDI is essential to ensure bearings that meet the allowed liner thickness remain in service.  Destructive inspection methodologies or technologies will not be considered.

The following capabilities are desired:

  • Inspection methodology that is accurate and simple enough to be conducted frequently to detect rapid wear progression.
  • Inspection to occur with pitch link assembly still installed on aircraft and minimum to no intrusion on surrounding components, hardware, etc.
  • Man-portable and light enough to carry on ladders and scaffolds.
  • Currently suitable (or can be ruggedized) for field environment.


Submission Requirements

Please provide the following information via White Paper:

  1. A brief description of your company/organization, small/large business status, and any additional socioeconomic status designation(s) (i.e., 8a, HUB-zone status, veteran-owned status, etc.).
  2. A technical White Paper (3 pages or less in font no smaller than size 12 Times New Roman, submitted as a PDF file, describing your company’s technology and/or current products that could provide the Navy and Marine Corps with the ability to conduct on aircraft bearing liner measurements while meeting the aforementioned capability desires.
  3. Identify the Technology Readiness Level (TRL) of your company’s product and how this was assessed.
  4. If applicable, provide information/status on the completion of government testing/demonstration of your technology under other contracts, as well as a summary of applications that demonstrate that your product’s capabilities have been successfully employed by the Department of Defense (DOD), government, and/or commercial activities.
  5. Provide a rough order of magnitude cost and delivery lead-time estimate for your product(s).
  6. Provide your point(s) of contact: Name, telephone number, email, and Commercial and Government Entity (CAGE) Code.
  7. For planning purposes, provide an approximate number of personnel who would attend the Industry Day/Technology Scan Event, if your company is invited to participate.



White Papers must be submitted no later than 5:00 p.m. (EST), March 20, 2024, via email to

All respondents must be U.S.-based and U.S.-owned companies.

Disclaimer and other Legal information

Responding to a Sources Sought, RFI or Survey does not guarantee that a CTMA Program Initiative will result. By submitting a response, you are agreeing to allow NCMS to share your information with the United States Government. All submissions containing proprietary information shall be marked accordingly.

Under the CTMA Program, the parties shall limit participation on the project to (1) U.S. citizens, (2) lawful permanent residents as defined by 8 U.S.C. 1101(a)(20), (3) other protected individuals as defined by 8 U.S.C. 1324b(a)(3) and (4) Canadian citizens (pursuant to the principles underlying the Canada-U.S. Free Trade Agreement), if such participation will involve visual inspection of the Technology, Intellectual Property or Technical Information, or oral exchanges of information about the foregoing. We also require the project participants to furnish NCMS, upon request, with proof of the citizenship status of its personnel participating on the project, including (1) U.S. citizens; (2) legal permanent residents; and (3) foreign nationals who are not permanent residents. In instances where it is necessary to involve foreign national employees in the visual inspection of the Technology, Intellectual Property, or Technical Information, or oral exchanges of information about the foregoing, the parties will be required to furnish to NCMS proof of appropriate valid export license, or technical assistance agreement, or exemption from licensing requirements (e.g. Canadian exemption) to the extent required by the International Traffic In Arms Regulations (“ITAR”) or the Export Administration Regulations (“EAR”). A copy of such license or agreement shall be furnished to NCMS before any disclosure of information to such foreign person. In the event a party believes that the subject matter of the project agreement is not covered by ITAR, that party may request a written waiver of the requirements of foreign national provision in the CTMA Agreement, which may be granted if the NCMS contracting officer agrees that ITAR does not cover the subject matter.

These requirements also apply to individuals who have dual citizenship status.