Text in force at CS23-6: from CS23-5, effective 15 Aug 2017.
(a) Powerplant installation support systems are all systems whose direct purpose is to support the powerplant or the energy storage device in its intended function as part of the powerplant installation.
(b) Powerplant installation support systems that have a direct effect on the engine availability are considered in the engine reliability.
(c) Powerplant installation support systems are designed for the operating conditions applicable to the location of installation.
(d) Systems must be capable of operating under the conditions likely to occur.
(e) System function and characteristics that have an effect on the powerplant installation system performance are established.
(f) Ingestion of likely foreign objects that would be hazardous to the engine is prevented.
(g) The pilot must be aware of the air intake configuration and able to influence it.
(h) Any likely single failures of powerplant installation support systems that result in a critical loss of thrust are mitigated.
ED Decision 2017/013/R · Source