{"data":{"id":"us/14-cfr-21.120","jurisdiction":"us","citation":"14 CFR 21.120","heading":"Responsibility of supplemental type certificate holders to provide written permission for alterations.","body":"A supplemental type certificate holder who allows a person to use the supplemental type certificate to alter an aircraft, aircraft engine, or propeller must provide that person with written permission acceptable to the FAA.","path":["Title 14—Aeronautics and Space","CHAPTER I—FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION","SUBCHAPTER C—AIRCRAFT","PART 21—CERTIFICATION PROCEDURES FOR PRODUCTS AND ARTICLES","Subpart E—Supplemental Type Certificates"],"source_url":"https://www.ecfr.gov/api/versioner/v1/full/2026-08-25/title-14.xml","current_through":"2026-08-25","vintage":"","retrieved_at":"2026-08-27T02:24:20Z","sha256":"3b6706197c3665a3d8ab8ad659a6fe1cc86278eaaa320e721f99e831f4a5c200","source_id":"us-cfr","stale":true,"prev":"us/14-cfr-21.119","next":"us/14-cfr-21.121"},"notice":"GroundRules: Original legal text. Not legal advice."}