[Code of Federal Regulations] [Title 14, Volume 4] [Revised as of January 1, 2008] From the U.S. Government Printing Office via GPO Access [CITE: 14CFR406.157] [Page 511] TITLE 14--AERONAUTICS AND SPACE CHAPTER III--COMMERCIAL SPACE TRANSPORTATION, FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION PART 406_INVESTIGATIONS, ENFORCEMENT, AND ADMINISTRATIVE REVIEW--Table of Subpart B_Rules of Practice in FAA Space Transportation Adjudications Sec. 406.157 Expert or opinion witnesses. An employee of the FAA may not be called as an expert or opinion witness for any party other than the agency, in any proceeding governed by this part. An employee of a respondent may not be called as an expert or opinion witness for the complainant in any proceeding governed by this part to which the respondent is a party.