[Code of Federal Regulations] [Title 14, Volume 1] [Revised as of January 1, 2003] From the U.S. Government Printing Office via GPO Access [CITE: 14CFR21.91] [Page 128] TITLE 14--AERONAUTICS AND SPACE CHAPTER I--FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION PART 21--CERTIFICATION PROCEDURES FOR PRODUCTS AND PARTS--Table of Contents Subpart D--Changes to Type Certificates Sec. 21.91 Applicability. Source: Docket No. 5085, 29 FR 14567, Oct. 24, 1964, unless otherwise noted. This subpart prescribes procedural requirements for the approval of changes to type certificates.