Legal Interpretations
Bicks 1991
Summary
The Question
May an aircraft owner or operator contract with another party, such as a manufacturer, to produce a part for maintaining or altering the aircraft under 14 CFR 21.303(b)(2)?
Background
An attorney at the law firm Burch, Porter & Johnson filed a FOIA request about 14 CFR 21.303(b)(2), which was replaced by a request to clarify the regulation. The FAA assumed the aircraft was FAA type certificated.
The FAA’s Interpretation
Yes, with conditions. The owner or operator keeps full responsibility that the part meets the FAA-approved type design and is safe to install; the contractor is merely its manufacturing agent. Production is one-for-one only; parts for other owners require Parts Manufacturer Approval under 14 CFR part 21, subpart K. Producing the part does not authorize installation, which certificated airmen (such as under 14 CFR part 65) must complete under 14 CFR part 43.
- Requester
- Bicks
- Issued
- April 25, 1991
- Subjects
- Maintenance & Repair Stations · Aircraft & Parts Certification
Regulations Cited
Page 1
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to a March 3.8 telephone conversation between you and Robert Robino of my staff, we are deeming your FOIA request withdrawn and replaced by a request for a clarification of the subject regulation.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:
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.
Page 2
(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
Regulations Referenced
Snapshot retrieved August 6, 2026.