[Code of Federal Regulations] [Title 14, Volume 2] [Revised as of January 1, 2008] From the U.S. Government Printing Office via GPO Access [CITE: 14CFR125.153] [Page 993] TITLE 14--AERONAUTICS AND SPACE CHAPTER I--FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) PART 125_CERTIFICATION AND OPERATIONS: AIRPLANES HAVING A SEATING CAPACITY OF Subpart E_Special Airworthiness Requirements Sec. 125.153 Flammable fluids. (a) No tanks or reservoirs that are a part of a system containing flammable fluids or gases may be located in designated fire zones, except where the fluid contained, the design of the system, the materials used in the tank, the shutoff means, and the connections, lines, and controls provide equivalent safety. (b) At least one-half inch of clear airspace must be provided between any tank or reservior and a firewall or shroud isolating a designated fire zone.