ED Decision 2003/15/RM
Compliance with CS 27.955 may not be jeopardised by failure of:
(a) Any one pump except pumps that are approved and installed as parts of a type certificated engine; or
(b) Any component required for pump operation except, for engine driven pumps, the engine served by that pump.
CS 27.993 Fuel system lines and fittings
ED Decision 2003/15/RM
(a) Each fuel line must be installed and supported to prevent excessive vibration and to withstand loads due to fuel pressure and accelerated flight conditions.
(b) Each fuel line connected to components of the rotorcraft between which relative motion could exist must have provisions for flexibility.
(c) Flexible hose must be approved.
(d) Each flexible connection in fuel lines that may be under pressure or subjected to axial loading must use flexible hose assemblies.
(e) No flexible hose that might be adversely affected by high temperatures may be used where excessive temperatures will exist during operation or after engine shutdown.
ED Decision 2003/15/RM
(a) There must be a positive, quick-acting valve to shut-off fuel to each engine individually.
(b) The control for this valve must be within easy reach of appropriate crew members.
(c) Where there is more than one source of fuel supply there must be means for independent feeding from each source.
(d) No shut-off valve may be on the engine side of any firewall.
CS 27.997 Fuel strainer or filter
ED Decision 2003/15/RM
There must be a fuel strainer or filter between the fuel tank outlet and the inlet of the first fuel system component which is susceptible to fuel contamination, including but not limited to the fuel metering device or an engine positive displacement pump, whichever is nearer the fuel tank outlet. This fuel strainer or filter must:
(a) Be accessible for draining and cleaning and must incorporate a screen or element which is easily removable;
(b) Have a sediment trap and drain except that it need not have a drain if the strainer or filter is easily removable for drain purposes;
(c) Be mounted so that its weight is not supported by the connecting lines or by the inlet or outlet connections of the strainer or filter itself, unless adequate strength margins under all loading conditions are provided in the lines and connections; and
(d) Provide a means to remove from the fuel any contaminant which would jeopardise the flow of fuel through rotorcraft or engine fuel system components required for proper rotorcraft fuel system or engine fuel system operation.
ED Decision 2003/15/RM
(a) There must be at least one accessible drain at the lowest point in each fuel system to completely drain the system with the rotorcraft in any ground attitude to be expected in service.
(b) Each drain required by sub-paragraph (a) must:
(1) Discharge clear of all parts of the rotorcraft;
(2) Have manual or automatic means to assure positive closure in the off 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.