CS 25.999 Fuel systems drains

(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 sub-paragraph (a) of this paragraph must –

(1)Discharge clear of all parts of the aeroplane;

(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.