§ 21.1 Applicability and definitions.

(a) This part prescribes— (1) Procedural requirements for issuing and changing— (i) Design approvals; (ii) Production approvals; (iii) Airworthiness certificates; and (iv) Airworthiness approvals; (2) Rules governing applicants for, and holders of, any approval or certificate specified in paragraph (a)(1) of this section; and (3) Procedural requirements for the approval of articles. (b) For the purposes of this part— (1) Airworthiness approval means a document, issued by the FAA for an aircraft, aircraft engine, propeller, or article, which certifies that the aircraft, aircraft engine, propeller, or article conforms to its approved design and is in a condition for safe operation, unless otherwise specified; (2) Article means a material, part, component, process, or appliance; (3) Commercial part means an article that is listed on an FAA-approved Commercial Parts List included in a design approval holder's Instructions for Continued Airworthiness required by § 21.50; (4) Design approval means a type certificate (including amended and supplemental type certificates) or the approved design under a PMA, TSO authorization, letter of TSO design approval, or other approved design; (5) Interface component means an article that serves as a functional interface between an aircraft and an aircraft engine, an aircraft engine and a propeller, or an aircraft and a propeller. An interface component is designated by the holder of the type certificate or the supplemental type certificate who controls the approved design data for that article; (6) Product means an aircraft, aircraft engine, or propeller; (7) Production approval means a document issued by the FAA to a person that allows the production of a product or article in accordance with its approved design and approved quality system, and can take the form of a production certificate, a PMA, or a TSO authorization; (8) State of Design means the country or jurisdiction having regulatory authority over the organization responsible for the design and continued airworthiness of a civil aeronautical product or article; (9) State of Manufacture means the country or jurisdiction having regulatory authority over the organization responsible for the production and airworthiness of a civil aeronautical product or article. (10) Supplier means a person at any tier in the supply chain who provides a product, article, or service that is used or consumed in the design or manufacture of, or installed on, a product or article.