Airworthiness Directive · Amendment 39-22880 · Main rotor drive system and 6700, rotorcraft flight control
Robinson Helicopter Company
This AD applies to Robinson Helicopter Company Model R44 helicopters serial numbers (S/Ns) up to 2480 inclusive and 30001 through 30022 inclusive, and Model R44 II helicopters S/Ns up to 14089 inclusive, certificated in any category, with riveted belt tension clutch actuator brackets part number A185-1, A185-2, or A185-5 (bracket(s)), installed.
Note 1 to paragraph (c): Helicopters with an R44 Cadet designation are Model R44 helicopters.
Note 2 to paragraph (c): Brackets attached to the fan scroll housing with screws are not applicable to this AD.
The FAA is adopting a new airworthiness directive (AD) for certain Robinson Helicopter Company Model R44 and R44 II helicopters. This AD was prompted by several reports of failed clutch actuators and failed rivets attaching the belt tension clutch actuator brackets (bracket) to the fan scroll housing. This AD requires inspecting each bracket and, depending on the results, accomplishing additional inspections or taking any necessary corrective actions. The FAA is issuing this AD to address the unsafe condition on these products.
Within 300 hours time-in-service or 12 months after the effective date of this AD, whichever occurs first, with the fanwheel removed, inspect each bracket installed on the fan scroll housing for looseness (bracket can be moved by hand) and fretting and accomplish the actions in paragraphs (g)(1) or (2) of this AD, as applicable.
(1) If there is no looseness of any bracket and no fretting, before further flight, visually inspect the fiberglass adjacent to the rivets of the fan scroll housing for delamination.
(i) If there is any delamination in the fiberglass, before further flight, remove the fan scroll housing from service and install an airworthy fan scroll housing using 5/32 -inch rivets (3 rivets on each top bracket and 6 rivets on the bottom bracket). Figure 1 of Robinson Helicopter Company R44 Service Letter SL-61B, Revision B, dated March 16, 2023 (SL-61B) depicts the location of each bracket and rivet.
(ii) If there is no delamination in the fiberglass, before further flight, inspect for the installation of 5/32 -inch rivets in all 12 locations (3 rivets on each top bracket and 6 rivets on the bottom bracket) depicted in Figure 1 of SL-61B. If a 5/32 -inch rivet is not installed in all 12 locations, before further flight, replace each incorrectly sized rivet and each missing rivet with a 5/32 -inch rivet.
(iii) Apply a horizontal torque stripe to each rivet.
(2) If any bracket is loose or has any fretting, before further flight, remove all brackets and inner plates from the fan scroll housing and accomplish the actions in paragraphs (g)(2)(i) through (iv) of this AD.
(i) For each bracket with fretting, before further flight, remove the bracket from service and replace it with an airworthy bracket.
(ii) Visually inspect each bracket and inner plate for cracks and deformation, visually inspect the fiberglass adjacent to the rivets of the fan scroll housing for delamination, and visually inspect each fan scroll housing rivet hole for delamination and other damage, which may be indicated by fretting.
(A) If a bracket or inner plate has any cracks or deformation, before further flight, remove the affected part from service and replace it with an airworthy part.
(B) If there is any delamination in the fiberglass or in any fan scroll housing rivet hole, before further flight, remove the fan scroll housing from service and install an airworthy fan scroll housing using 5/32 -inch rivets (3 rivets on each top bracket and 6 rivets on the bottom bracket). Figure 1 of SL-61B depicts the location of each bracket and rivet.
(C) If there is other damage in any fan scroll housing rivet hole, before further flight, repair the rivet hole in accordance with FAA-approved procedures.
(iii) After accomplishing the actions in paragraphs (g)(2)(i) and (ii) of this AD, when installing or reinstalling the brackets and inner plates on the fan scroll housing, use 5/32 -inch rivets in all 12 locations depicted in Figure 1 of SL-61B (3 rivets on each top bracket and 6 rivets on the bottom bracket).
(iv) Apply a horizontal torque stripe to each rivet.
The aircraft, engines and makers this AD names, by the model designations in its text. A model listed here may still be outside the AD's serial ranges.
Aircraft
