Text in force at 29-59: from 29-26, effective 3 Oct 1988.
(a) Each fuselage and rotor pylon structure must be designed to withstand--
(1) The critical loads prescribed in Secs. 29.337 through 29.341, and 29.351;
(2) The applicable ground loads prescribed in Secs. 29.235, 29.471 through 29.485, 29.493, 29.497, 29.505, and 29.521; and
(3) The loads prescribed in Sec. 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) Deleted.]
[(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.]
53 FR 34215 · Source