Aircraft

STANDARD PARTS

WHAT IS A STANDARD PART? Mentioning standard parts usually brings to mind the

thought of merely “nuts or bolts” when, in fact, other types of parts as well as materials used to produce aviation parts may fall under the category of “standard part.” A standard part is a part or material that conforms to an established industry or U.S. Government-published specification. TheFAA’s acceptance of a standard part as an approved part is based on the certification that the part has been designed and produced in accordance with an independent established set of specifications and criteria. “Standard part” is not defined in Title 14 of the Code of Federal Regulations. Section 21.303(b) provides four exceptions to the requirement to hold a Parts Manufacturer Approval to producereplacement and modification aircraft parts. Section 21.303(b)(4) provides the exception for standard parts -- bolts and nuts -- which are parts that conform to established industry or U.S. specifications. The FAA has published a non-regulatory definition of “standard part” as well as interpretative information regarding what criteria parts must meet to come under the standard part category.Advisory Circular 21-29 (pdf), Detecting and Reporting Suspected Unapproved Parts, provides the following definition of “standard part”:
A part manufactured in complete compliance with an established industry or U.S. Government specification which includes design, manufacturing, test and acceptance criteria, and uniform identification requirements; or for a type of part which the Administrator has founddemonstrates conformity based solely on meeting performance criteria, is in complete compliance with an established industry or U.S. Government specification which contains performance criteria, test and acceptance criteria, and uniform identification requirements. The specification must include all information necessary to produce and conform the part and be published so that any party maymanufacture the part. Examples include, but are not limited to, National Aerospace Standard (NAS), Army-Navy Aeronautical Standard (AN), Society of Automotive Engineers (SAE), SAE Sematec, Joint Electron Device Engineering Council, Joint Electron Tube Engineering Council, and American National Standards Institute (ANSI).

This definition incorporates two categories of standard part criteria.Initially, the FAA recognized as “standard” those parts that met published specifications that included information clearly establishing design, materials, manufacture, and uniform identification requirements. The FAA issued a subsequent interpretation of standard part that provided for a class of parts conforming to a standard not based on their physical configuration but on their meeting a specifiedperformance criterion. The FAA stated this second category of standard parts is best exemplified by discrete electrical and electronic parts. See 62 Fed. Reg. 9,923 (1997). The FAA must make a specific finding of applicability to a class of parts before the “performance only” criterion can be used.
REGULATORY OVERSIGHT. The FAA does not certificate manufacturers of standard

parts. However, when atype design calls for the installation of a standard part, the FAA may conduct surveillance of the manufacturer and/or supplier of that part.

The FAA has previously noted that standard part manufacturers are subject to continuing in-depth audits by their customers, and these audits provide an appropriate degree of confidence that the standards are being met. A standard part must conform tothe designated part specification in order to qualify as a standard part. Accordingly, the production of a standard part offered for sale for installation on a type-certificated product where that part does not conform to the standard part specification may be a violation of section 21.303(a). Recognizing that billions of fasteners are used in the American economy each year, Congress enacted the...