Legal Interpretations
Bicks 1991
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April 25, 1991 Mr. Nathan A. Bicks Law Offices of Burch, Porter & Johnson 130 North court Avenue Memphis, Tennessee 38103
Dear Mr. Bicks:
This is the follow-up response to our letter of March 25 concerning your February 28 Freedom of Information Act (FOIA) request for all allowable information pertaining to section. 21.303(b)(2) of the Federal Aviation Regulations (FAR), 14 C.F.R. § 21.303(b)(2). Pursuant to a March 3.8 telephone conversation between you and Robert Robino of my staff, we are deeming your FOIA request withdrawn and replaced by a request for a clarification of the subject regulation. Our understanding of your question is, "whether an owner or operator may contract with another party (such as a manufacturer) to produce the part which will be used to maintain or alter his aircraft." The following is our answer based on the assumption that the owner's or operator's aircraft .is a Federal Aviation Administration (FAA) type certificated aircraft.
The answer is yes, an owner or operator may contract with another party (such as a manufacturer) to produce the part on his behalf. However, there are additional requirements that should be clearly understood by the owner or operator prior to pursuing this procedure of producing replacement parts. These would include the following: (1) The owner or operator retains full responsibility for ensuring that the new part meets all the requirements of the original FAA-approved type design (e.g., all materials are the same, all special manufacturing processes are completed, all -dimensional and structural characteristics are identical, etc.), and that the part is safe for installation on the applicable FAA type certificated aircraft. This would typically involve the owner or operator obtaining from the original part manufacturer, and providing to the contracted party, all the appropriate FAA-approved design data required to manufacture the part. The contracted party is merely acting as a manufacturing agent of the owner or operator.
(2) The part must be manufactured on a "one-for-one" replacement basis only. That is, the owner or operator may produce, or have a contracted party produce, only one replacement part for the maintenance or alteration of the aircraft. No additional parts, for sale or use by other owners and operators of similar aircraft, may be produced unless the owner or operator, or contracted party; obtains an FAA Parts Manufacturer Approval pursuant to the requirements of FAR, Part 21, Subpart K, 14 C.F.R. Part 21, Subpart K.
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(3) The manufacture of replacement parts by an owner or operator (or a contracted party, as allowed under the provisions of FAR, section 21.303(b)(2)), does not in itself authorize the installation of the replacement parts onto the designated FAA type certificated aircraft. Installation, conformity inspections of FAA approved type design, appropriate documentation requirements, etc., must be completed by certificated airmen such as those described in FAR Part 65, pursuant to the maintenance and alteration requirements of FAR Part 43.
I hope this information has been helpful to you, and clarifies the requirements of the FAR you have cited. If you should require any additional information, please submit a separate request for that information at your convenience.
Sincerely,
Original Signed By Dana D. Lakeman Acting Manager, Aircraft Manufacturing Division
Retrieved from ecfr.gov on July 18, 2026.