[Code of Federal Regulations] [Title 14, Volume 1] [Revised as of January 1, 2007] From the U.S. Government Printing Office via GPO Access [CITE: 14CFR39.27] [Page 887] TITLE 14--AERONAUTICS AND SPACE CHAPTER I--FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION PART 39_AIRWORTHINESS DIRECTIVES--Table of Contents Sec. 39.27 What do I do if the airworthiness directive conflicts with the service document on which it is based? In some cases an airworthiness directive incorporates by reference a manufacturer's service document. In these cases, the service document becomes part of the airworthiness directive. In some cases the directions in the service document may be modified by the airworthiness directive. If there is a conflict between the service document and the airworthiness directive, you must follow the requirements of the airworthiness directive.