Engines.

CFR · 2024-01-01 · US · Title 14

(a) (b) (i) The fan blades are contained in case of failure; (ii) Each fan is located so that a failure will not jeopardize safety; or (iii) Each fan blade can withstand an ultimate load of 1.5 times the centrifugal force resulting from operation limited by the following: (A) For fans driven directly by the engine— ( ( (B) For fans driven by the rotor drive system, the maximum rotor drive system rotational speed to be expected in service, including transients. (2) Unless a fatigue evaluation under § 27.571 is conducted, it must be shown that cooling fan blades are not operating at resonant conditions within the operating limits of the rotorcraft. (c) (d) (2) Except for the in-flight shutdown of all engines, engine restart capability must be demonstrated throughout a flight envelope for the rotorcraft. (3) Following the in-flight shutdown of all engines, in-flight engine restart capability must be provided.

official document · source cfr-2024 · id 14:§ 27.903