ED Decision 2003/15/RM
(a) Each engine must have an independent oil system that can supply it with an appropriate quantity of oil at a temperature not above that safe for continuous operation.
(b) The usable oil capacity of each system may not be less than the product of the endurance of the rotorcraft under critical operating conditions and the maximum oil consumption of the engine under the same conditions, plus a suitable margin to ensure adequate circulation and cooling. Instead of a rational analysis of endurance and consumption, a usable oil capacity of 3.8 litres (0.83 Imperial gallon /1 US gallon) for each 151 litres (33.3 Imperial gallons/40 US gallons) of usable fuel may be used.
(c) The oil cooling provisions for each engine must be able to maintain the oil inlet temperature to that engine at or below the maximum established value. This must be shown by flight tests.
ED Decision 2003/15/RM
Each oil tank must be designed and installed so that –
(a) It can withstand, without failure, each vibration, inertia, fluid, and structural load expected in operation;
(b) (Reserved)
(c) Where used with a reciprocating engine, it has an expansion space of not less than the greater of 10% of the tank capacity or 1.9 litre (0.42 Imperial gallon/0.5 US gallon), and where used with a turbine engine, it has an expansion space of not less than 10% of the tank capacity.
(d) It is impossible to fill the tank expansion space inadvertently with the rotorcraft in the normal ground attitude;
(e) Adequate venting is provided; and
(f) There are means in the filler opening to prevent oil overflow from entering the oil tank compartment.
ED Decision 2003/15/RM
Each oil tank must be designed and installed so that it can withstand, without leakage, an internal pressure of 34 kPa (5 psi), except that each pressurised oil tank used with a turbine engine must be designed and installed so that it can withstand, without leakage, an internal pressure of 34 kPa (5 psi), plus the maximum operating pressure of the tank.
CS 27.1017 Oil lines and fittings
ED Decision 2003/15/RM
(a) Each oil line must be supported to prevent excessive vibration.
(b) Each oil 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 oil line must have an inside diameter of not less than the inside diameter of the engine inlet or outlet. No line may have splices between connections.
CS 27.1019 Oil strainer or filter
ED Decision 2003/15/RM
(a) Each turbine engine installation must incorporate an oil strainer or filter through which all of the engine oil flows and which meets the following requirements:
(1) Each oil strainer or filter that has a bypass must be constructed and installed so that oil will flow at the normal rate through the rest of the system with the strainer or filter completely blocked.
(2) The oil strainer or filter must have the capacity (with respect to operating limitations established for the engine) to ensure that engine oil system functioning is not impaired when the oil is contaminated to a degree (with respect to particle size and density) that is greater than that established for the engine under CS-E.
(3) The oil strainer or filter, unless it is installed at an oil tank outlet, must incorporate a means to indicate contamination before it reaches the capacity established in accordance with sub-paragraph (a)(2).
(4) The bypass of a strainer or filter must be constructed and installed so that the release of collected contaminants is minimised by appropriate location of the bypass to ensure that collected contaminants are not in the bypass flow path.
(5) An oil strainer or filter that has no bypass, except one that is installed at an oil tank outlet, must have a means to connect it to the warning system required in CS 27.1305(r).
(b) Each oil strainer or filter in a powerplant installation using reciprocating engines must be constructed and installed so that oil will flow at the normal rate through the rest of the system with the strainer or filter element completely blocked.
ED Decision 2003/15/RM
A drain (or drains) must be provided to allow safe drainage of the oil system. Each drain must:
(a) Be accessible; and
(b) Have manual or automatic means for positive locking in the closed position.
CS 27.1027 Transmissions and gearboxes: general
ED Decision 2003/15/RM
(a) The lubrication system for components of the rotor drive system that require continuous lubrication must be sufficiently independent of the lubrication systems of the engine(s) to ensure lubrication during autorotation.
(b) Pressure lubrication systems for transmissions and gear-boxes must comply with the engine oil system requirements of CS 27.1013 (except sub-paragraph (c)), CS 27.1015, 27.1017, 27.1021, and 27.1337(d).
(c) Each pressure lubrication system must have an oil strainer or filter through which all of the lubricant flows and must –
(1) Be designed to remove from the lubricant any contaminant which may damage transmission and drive system components or impede the flow of lubricant to a hazardous degree;
(2) Be equipped with a means to indicate collection of contaminants on the filter or strainer at or before opening of the bypass required by sub-paragraph (c)(3); and
(3) Be equipped with a bypass constructed and installed so that:
(i) The lubricant will flow at the normal rate through the rest of the system with the strainer or filter completely blocked; and
(ii) The release of collected contaminants is minimised by appropriate location of the bypass to ensure that collected contaminants are not in the bypass flow path.
(d) For each lubricant tank or sump outlet supplying lubrication to rotor drive systems and rotor drive system components, a screen must be provided to prevent entrance into the lubrication system of any object that might obstruct the flow of lubricant from the outlet to the filter required by sub-paragraph (c). The requirements of sub-paragraph (c) do not apply to screens installed at lubricant tank or sump outlets.
(e) Splash-type lubrication systems for rotor drive system gearboxes must comply with CS 27.1021 and 27.1337(d).