§29.1189 Shutoff means

(a) There m ust be m eans t o shut off or otherwise prevent hazardous quantities of fuel, oil, de-icing fluid, and ot her fl ammable fl uids from flowing i nto, wi thin, or t hrough any designated fire zone, except that this m eans need not be provided: (1) For lines, fittings, and com ponents forming an integral part of an engine; (2) For oil systems for turbine engine installations in which all components of t he oil system, i ncluding oi l t anks, are fireproof or located in areas not subject to engine fire conditions; or (3) For en gine o il system s in Categ ory B rotorcraft using reciprocating engines of less than 8195 cm3 (500 cubic inches) displacement. (b) The cl osing of any fuel shut off val ve for any engi ne m ay not m ake fuel unavailable to the remaining engines. (c) For Category A rotorcraft no hazardous quantity o f flam mable flu id m ay d rain into any designated fire zone aft er shut off has been accomplished, nor m ay the closing of any fuel shutoff valve for an engi ne make fuel unavailable to the remaining engines. (d) The operat ion of any shut off m ay not interfere with the later emergency operation of any other equipm ent, such as the m eans for declutching the engine from the rotor drive. (e) Each shutoff valve and its control must be designed, l ocated, and prot ected t o funct ion properly under any condition likely to result from fire in a designated fire zone. (f) Except for ground-use-only auxiliary power unit in stallations, th ere m ust b e m eans to prevent inadvertent opera tion of each shutoff and to m ake it p ossible to re-o pen it in flig ht after it has been closed.