CS 25J1189 Shut-off means

• ED Decision 2005/006/R found in: CS-25 Amdt 27 - Large Aeroplanes (Jan 2023)

CS 25J1189 Shut-off means ED Decision 2005/006/R (See [AMC 25.1189](#_DxCrossRefBm1709821547)) (a) Each APU compartment specified in [CS 25J1181(a)](#_DxCrossRefBm1709821926) must have a means to shut-off or otherwise prevent hazardous quantities of flammable fluids, from flowing into, within, or through any designated fire zone, except that shut-off means are not required for: (1) Lines, fittings and components forming an integral part of an APU; and (2) Oil systems for APU installations in which all external components of the oil system, including the oil tanks, are fireproof. (b) The closing of any fuel shut-off valve for any APU may not make fuel unavailable to the main engines. (c) Operation of any shut-off may not interfere with the later emergency operation of other equipment. (d) Each flammable fluid shut-off means and control must be fireproof or must be located and protected so that any fire in a fire zone will not affect its operation. (e) No hazardous quantity of flammable fluid may drain into any designated fire zone after shut-off. (f) There must be means to guard against inadvertent operation of the shut-off means and to make it possible for the crew to reopen the shut-off means in flight after it has been closed. (g) Each tank to APU shut-off valve must be located so that the operation of the valve will not be affected by the APU mount structural failure. (h) Each shut-off valve must have a means to relieve excessive pressure accumulation unless a means for pressure relief is otherwise provided in the system. [Amdt 25/1]