CS 29.547 Main and tail rotor structure
ED Decision 2003/16/RM
(a) A rotor is an assembly of rotating components, which includes the rotor hub, blades, blade dampers, the pitch control mechanisms, and all other parts that rotate with the assembly.
(b) Each rotor assembly must be designed as prescribed in this paragraph and must function safely for the critical flight load and operating conditions. A design assessment must be performed, including a detailed failure analysis to identify all failures that will prevent continued safe flight or safe landing, and must identify the means to minimise the likelihood of their occurrence.
(c) The rotor structure must be designed to withstand the following loads prescribed in CS 29.337 to 29.341, and CS 29.351:
(1) Critical flight loads.
(2) Limit loads occurring under normal conditions of autorotation.
(d) The rotor structure must be designed to withstand loads simulating:
(1) For the rotor blades, hubs and flapping hinges, the impact force of each blade against its stop during ground operation; and
(2) Any other critical condition expected in normal operation.
(e) The rotor structure must be designed to withstand the limit torque at any rotational speed, including zero. In addition:
(1) The limit torque need not be greater than the torque defined by a torque limiting device (where provided), and may not be less than the greater of:
(i) The maximum torque likely to be transmitted to the rotor structure, in either direction, by the rotor drive or by sudden application of the rotor brake; and
(ii) For the main rotor, the limit engine torque specified in CS 29.361.
(2) The limit torque must be equally and rationally distributed to the rotor blades.
AMC 29.547 Main rotor and tail rotor structure
ED Decision 2012/022/R
Where Vibration Health Monitoring is used as a compensating provision to meet CS 29.547(b), the design and performance of the vibration health monitoring system should be approved by requesting compliance with CS 29.1465(a).
[Amdt 29/3]
CS 29.549 Fuselage and rotor pylon structures
ED Decision 2003/16/RM
(a) Each fuselage and rotor pylon structure must be designed to withstand:
(1) The critical loads prescribed in CS 29.337 to 29.341, and CS 29.351;
(2) The applicable ground loads prescribed in CS 29.235, 29.471 to 29.485, CS 29.493, 29.497, 29.505, and 29.521; and
(3) The loads prescribed in CS 29.547(d)(1) and (e)(1)(i).
(b) Auxiliary rotor thrust, the torque reaction of each rotor drive system, and the balancing air and inertia loads occurring under accelerated flight conditions, must be considered.
(c) Each engine mount and adjacent fuselage structure must be designed to withstand the loads occurring under accelerated flight and landing conditions, including engine torque.
(d) Reserved.
(e) If approval for the use of 2½-minute OEI power is requested, each engine mount and adjacent structure must be designed to withstand the loads resulting from a limit torque equal to 1.25 times the mean torque for 2½-minute power OEI combined with 1g flight loads.
CS 29.551 Auxiliary lifting surfaces
ED Decision 2003/16/RM
Each auxiliary lifting surface must be designed to withstand:
(a) The critical flight loads in CS 29.337 to 29.341, and CS 29.351;
(b) The applicable ground loads in CS 29.235, 29.471 to 29.485, CS 29.493, 29.505, and 29.521; and
(c) Any other critical condition expected in normal operation.