[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: 14CFR125.139] [Page 992] 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. 125.139 Oil system drains. Accessible drains incorporating either a manual or automatic means for positive locking in the closed position must be provided to allow safe drainage of the entire oil system.