2024-23-01: Main rotor drive system, Rotorcraft flight control

1. The authority citation for part 39 continues to read as follows: Authority: 49 U.S.C. 106(g), 40113, 44701. 2. The FAA amends § 39.13 by adding the following new airworthiness directive: 2024-23-01 Robinson Helicopter Company: Amendment 39-22880; Docket No. FAA-2024-1477; Project Identifier AD-2023-01015-R. (a) Effective Date This airworthiness directive (AD) is effective January 7, 2025. (b) Affected ADs None. (c) Applicability 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. (d) Subject Joint Aircraft System Component (JASC) Code: 6300, Main rotor drive system and 6700, Rotorcraft flight control. (e) Unsafe Condition This AD was prompted by several reports of failed clutch actuators and failed rivets attaching the belt tension clutch actuator brackets to the fan scroll housing. The FAA is issuing this AD to detect and address loose and missing brackets and rivets. The unsafe condition, if not addressed, could result in detachment of the bracket, causing failure of the clutch actuator assembly, loss of main and tail rotor drive, and subsequent loss of control of the helicopter. (f) Compliance Comply with this AD within the compliance times specified, unless already done. (g) Required Actions 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. (h) Special Flight Permits A one-time special flight permit may be issued in accordance with 14 CFR 21.197 and 21.199 to fly the aircraft to a location where the actions required by this AD can be accomplished. This flight must be a non-revenue flight and limited to only essential flight crew. (i) Alternative Methods of Compliance (AMOCs) (1) The Manager, West Certification Branch, FAA, has the authority to approve AMOCs for this AD, if requested using the procedures found in 14 CFR 39.19. In accordance with 14 CFR 39.19, send your request to your principal inspector or local Flight Standards District Office, as appropriate. If sending information directly to the manager of the West Certification Branch, send it to the attention of the person identified in paragraph (j) of this AD. Information may be emailed to: AMOC@faa.gov. (2) Before using any approved AMOC, notify your appropriate principal inspector, or lacking a principal inspector, the manager of the local flight standards district office/certificate holding district office. (j) Related Information For more information about this AD, contact Charles Ayala, Aviation Safety Engineer, FAA, 3960 Paramount Boulevard, Lakewood, CA 90712; phone: (562) 627-5226; email: Charles.L.Ayala@faa.gov. (k) Material Incorporated by Reference (1) The Director of the Federal Register approved the incorporation by reference (IBR) of the material listed in this paragraph under 5 U.S.C. 552(a) and 1 CFR part 51. (2) You must use this material as applicable to do the actions required by this AD, unless the AD specifies otherwise. (i) Robinson Helicopter Company R44 Service Letter SL-61B, Revision B, dated March 16, 2023. Note 3 to paragraph (k)(2)(i): The material identified in paragraph (k)(2)(i) of this AD is co-published as one document along with Robinson Helicopter Company R22 Service Letter SL-74B, Revision B, dated March 16, 2023, which is not incorporated by reference in this AD. (ii) [Reserved] (3) For Robinson Helicopter Company material identified in this AD, contact Robinson Helicopter Company, Technical Support Department, 2901 Airport Drive, Torrance, CA 90505; phone: (310) 539-0508; fax: (310) 539-5198; email: ts1@robinsonheli.com; or at robinsonheli.com. (4) You may view this material at the FAA, Office of Regional Counsel, Southwest Region, 10101 Hillwood Pkwy., Fort Worth, TX 76177. For information on the availability of this material at the FAA, call (817) 222-5110. (5) You may view this material at the National Archives and Records Administration (NARA). For information on the availability of this material at NARA, visit www.archives.gov/federal-register/cfr/ibr-locations or email: fr.inspection@nara.gov . Issued on November 4, 2024. Victor Wicklund, Deputy Director, Compliance & Airworthiness Division, Aircraft Certification Service. [FR Doc. 2024-28178 Filed 12-2-24; 8:45 am]BILLING CODE 4910-13-P