Text in force at 25-153: from 25-38, effective 1 Feb 1977.
(a) Drainage of the fuel system must be accomplished by the use of fuel strainer and fuel tank sump drains.
[(b) Each drain required by paragraph (a) of this section must--
(1) Discharge clear of all parts of the airplane:
(2) Have manual or automatic means for positive locking in the closed position; and
(3) Have a drain valve--
(i) That is readily accessible and which can be easily opened and closed; and
(ii) That is either located or protected to prevent fuel spillage in the event of a landing with landing gear retracted.]
41 FR 55467 · Source