§29.903 Engines

(a) (Reserved) (b) Category A; engine isolation. For each Category A rotorcraft, the powerplants m ust be arranged and isolated fro m each other to allow operation, in at least one configuration, so that the failure or malfunction of any engine, or the failure of any system th at can affect an y en gine, will not – (1) Prevent t he cont inued safe operat ion of the remaining engines; or (2) Require immediate act ion, ot her t han normal p ilot actio n with p rimary flig ht controls, by any crew member to maintain safe operation. (c) Category A; control of engine rotation. For each Category A rotorcraft, there m ust be a means for stopping the rot ation of any engi ne i ndividually in flight, except that, for turbine engine installations, the means for st opping the engine need be provided only where necessary for safety. In addition – (1) Each com ponent of the engine stopping system that is located on the engine side of the firewall, and t hat might be exposed to fire, must be at least fire resistant; or (2) Duplicate m eans m ust be available for stopping the engine and t he controls must be where all are not likely to be damaged at the same time in case of fire. (d) Turbine engine installation. For turbine engine installations, (1) Design precautions must be taken to minimise the hazards to th e rotorcraft in the event of an engine rotor failure; and, (2) The powerplant system s associated with engi ne cont rol devi ces, sy stems, and instrumentation m ust be desi gned t o give reasonable assurance t hat t hose engi ne operating limitations th at ad versely affect engine rotor structural integrity will not be exceeded in service. (e) Restart capability: (1) A means to restart any engine in flight must be provided. (2) Except for t he in-flight shutdown of all en gines, en gine restart cap ability must be demonstrated t hroughout a fl ight envel ope for the rotorcraft. (3) Following the in-flight shutdown of all en gines, in -flight en gine restart capability must be provided.