Legal Interpretations
Ross-MexmilGlobalServices 2008
Summary
The Question
Is a repair station's rebuilding of aircraft food tray tables with fabricated replacement parts maintenance, or is it manufacturing?
Background
Mexmil Global Services, a certificated repair station, repairs tray tables with DER-approved data, fabricating replacement parts and reusing only two internal fittings and four attaching parts. Its principal maintenance inspector questioned whether this is maintenance and consulted the local Manufacturing Inspection District Office.
The FAA’s Interpretation
The FAA declined to decide because the question requires fact-specific determinations, and referred it to Flight Standards. It noted that under AC 43-18, or another method acceptable to the Administrator, an appropriately rated certificate holder with proper design data and a fabrication quality control system may fabricate parts for its own repairs, but selling such parts separately requires a PMA under 14 CFR 21.303(a).
- Requester
- Ross
- Organization
- MexmilGlobalServices
- Issued
- November 14, 2008
- Subject
- Aircraft & Parts Certification
Regulations Cited
Page 1
U.S. Department
of Transportation
Federal Aviation
Administration
NOV 1 4 2008
Mr. Greg Ross
Mexmil Global Services, Inc.
Manager of QC/QA
3100 Technology Drive
Suite 100
Plano, Texas 75074
Office of the Chief Counsel 800 Independence Ave .. S.W.
Washington, D.C. 20591
Re: Request for Interpretation on Fabrication vs. Manufacture Issue
Dear Mr. Ross:
This is in response to a Jetter dated July 8, 2008, from Mr. Barry K. Muhler, the former Manager of QC/QA for Mexmil Global Services, Inc. (MOS), in which he asked for a Federal Aviation Administration (FAA) legal interpretation on whether certain work on aircraft food tray tables is considered by the FAA to be fabrication incorporated into a repair during maintenance or whether it is manufacturing.
Specifically, Mr. Muhler stated that MOS (an FAA-certificated repair station) has approved data for repair of the tray tables at issue, and that this data was obtained through the services of a Designated Engineering Representative (DER) and documented on an FAA Form 8110- 3 (Statement of Compliance with the Federal Aviation Regulations). He also stated that the repair's entail "the disassembly of the tray tables, fabrication of replacement parts under 21.305(d) and AC 43.18 [sic], and reassembly of the tray table." You expressed your belief that those activities by MOS meet the definition of maintenance in the regulations. Mr. Muhler stated that the Principal Maintenance Inspector (PMI) for MOS has expressed concerns whether MGS was in fact performing maintenance since "the only portions of the original table that was [sic] re-used were two fittings that are inside the structure and 4 parts that attach to those fittings." Mr. Muhler also stated that, because of those circumstances, the PMI contacted the FAA's local Manufacturing Inspection District Office (MIDO) and sent a cop~ of your repair information to that office. According to Mr. Muhler, the PMI advised him that the MIDO believes MGS's work on the tray tables is manufacturing. However, when our office contacted your PMI on this matter, he told us that the MIDO has not yet responded to his inquiry. ·
Page 2
As noted above, Mr. Muhler' s letter referenced Advisory Circular 43-18 (Fabrication of Aircraft Parts by Maintenance Personnel), which provides guidance to maintenance providers who need to fabricate parts to be consumed into maintenance or alteration of a civil aviation product. If a person follows the guidance in the AC (or another method that is acceptable to the Administrator), the person could legally fabricate a part that is to be used in a repair or alteration and not run afoul of the regulations that require FAA approval to make a part for sale for installation on a type-certificated product (i.e., 14 C.F.R. § 21.303(a)). Paragraph 4 of the AC provides that, an appropriately rated certificate holder that fabricates a part in the course of performing maintenance or alterations must possess:
Approved design data or data acceptable to the Administrator that is determined by the category classification for the part being fabricated; and (2) A fabrication quality control system (FQCS) to ensure each fabricated part conforms to its design data and is in condition for safe operation. Accordingly, if MGS met those criteria, it could fabricate a part that would be incorporated into a repair it was performing.
Paragraph 5 of the AC provides the cautionary note: "A certificate holder that desires to sell his/her fabricated parts separately (i.e., outside the course of performing maintenance or an alteration) must obtain a PMA [Parts Manufacturing Approval] (ref. 14 CFR section 21.303(a))."
Whether MGS's work on aircraft tray tables is maintenance or manufacturing requires factspecific determ inations to be made and cannot presently be answered definitively by this office. Therefore, we are providing your information and additional information we obtained to the FAA' s Flight Standards Service for its disposition of the matter. This response was prepared by Edmund Averman, an Attorney in the Regulations Division of the Office of the Chief Counsel and coordinated with the Aircraft Maintenance Division of the Office of Flight Standards. If you have additional questions regarding this matter, please contact us at your convenience at (202) 267-3073.
Sincerely,
~Z:o~Assistant Chief Counsel for Regulations, AGC-200
Regulations Referenced
Snapshot retrieved August 6, 2026.