Airworthiness Directives; Restricted Category Model CH-47D Helicopters

DEPARTMENT OF TRANSPORTATION <SUBAGY>Federal Aviation Administration</SUBAGY> <CFR>14 CFR Part 39</CFR> <DEPDOC>[Docket No. FAA-2025-5394; Project Identifier AD-2025-01194-R]</DEPDOC> <RIN>RIN 2120-AA64</RIN> <SUBJECT>Airworthiness Directives; Restricted Category Model CH-47D Helicopters</SUBJECT> <HD SOURCE="HED">AGENCY:</HD> Federal Aviation Administration (FAA), DOT. <HD SOURCE="HED">ACTION:</HD> Notice of proposed rulemaking (NPRM). <SUM> <HD SOURCE="HED">SUMMARY:</HD> The FAA proposes to adopt a new airworthiness directive (AD) for all restricted category Model CH-47D helicopters. This proposed AD was prompted by reports of fatigue cracking of the right-hand (RH) forward transmission support beam fitting. This proposed AD would require repetitively inspecting the RH forward transmission support beam fitting for cracking and, depending on the results, repairing any crack(s). This proposed AD would also require submitting data on any previous repairs and replaced fittings. The FAA is proposing this AD to address the unsafe condition on these products. </SUM> <DATES> <HD SOURCE="HED">DATES:</HD> The FAA must receive comments on this proposed AD by February 5, 2026. </DATES> <HD SOURCE="HED">ADDRESSES:</HD> You may send comments, using the procedures found in 14 CFR 11.43 and 11.45, by any of the following methods: • <E T="03">Federal eRulemaking Portal:</E> Go to <E T="03">regulations.gov.</E> Follow the instructions for submitting comments. • <E T="03">Fax:</E> (202) 493-2251. • <E T="03">Mail:</E> U.S. Department of Transportation, Docket Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue SE, Washington, DC 20590. • <E T="03">Hand Delivery:</E> Deliver to Mail address above between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. <E T="03">AD Docket:</E> You may examine the AD docket at <E T="03">regulations.gov</E> under Docket No. FAA-2025-5394; or in person at Docket Operations between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The AD docket contains this NPRM, any comments received, and other information. The street address for Docket Operations is listed above. <FURINF> <HD SOURCE="HED">FOR FURTHER INFORMATION CONTACT:</HD> Sarah Illg, Aviation Safety Engineer, FAA, 3960 Paramount Boulevard, Lakewood, CA 90712; phone: (206) 231-3517; email: <E T="03">sarah.a.illg@faa.gov</E> . </FURINF> <SUPLINF> <HD SOURCE="HED">SUPPLEMENTARY INFORMATION:</HD> <HD SOURCE="HD1">Comments Invited</HD> The FAA invites you to send any written relevant data, views, or arguments about this proposal. Send your comments using a method listed under <E T="02">ADDRESSES</E> . Include “Docket No. FAA-2025-5394; Project Identifier AD-2025-01194-R” at the beginning of your comments. The most helpful comments reference a specific portion of the proposal, explain the reason for any recommended change, and include supporting data. The FAA will consider all comments received by the closing date and may revise this proposal because of those comments. Except for Confidential Business Information (CBI) as described in the following paragraph, and other information as described in 14 CFR 11.35, the FAA will post all comments received, without change, to <E T="03">regulations.gov</E> , including any personal information you provide. The agency will also post a report summarizing each substantive verbal contact received about this NPRM. <HD SOURCE="HD1">Confidential Business Information</HD> CBI is commercial or financial information that is both customarily and actually treated as private by its owner. Under the Freedom of Information Act (FOIA) (5 U.S.C. 552), CBI is exempt from public disclosure. If your comments responsive to this NPRM contain commercial or financial information that is customarily treated as private, that you actually treat as private, and that is relevant or responsive to this NPRM, it is important that you clearly designate the submitted comments as CBI. Please mark each page of your submission containing CBI as “PROPIN.” The FAA will treat such marked submissions as confidential under the FOIA, and they will not be placed in the public docket of this NPRM. Submissions containing CBI should be sent to Sarah Illg, Aviation Safety Engineer, FAA, 3960 Paramount Boulevard, Lakewood, CA 90712. Any commentary that the FAA receives which is not specifically designated as CBI will be placed in the public docket for this rulemaking. <HD SOURCE="HD1">Background</HD> The FAA received reports of fatigue cracking of the RH forward transmission support beam fitting having part number 145S1838-1 on CH-47D helicopters. CH-47D type certificate holders and operators have reported experiencing at least one cracking event around the fastener on the RH forward transmission support beam fitting at the right butt line (RBL) 18 from station (STA) 76 to STA 120. This condition, if not addressed, could result in crack propagation and lead to failure of the RH forward transmission support beam fitting, excessive vibration, and consequent loss of control of the helicopter. <HD SOURCE="HD1">FAA's Determination</HD> The FAA is issuing this NPRM after determining that the unsafe condition described previously is likely to exist or develop on other products of the same type design. <HD SOURCE="HD1">Proposed AD Requirements in This NPRM</HD> This proposed AD would require repetitively inspecting the RH forward transmission support beam fitting for cracking and, depending on the results, repairing any crack(s) or replacing parts. This proposed AD would also require submitting data on any previous repairs and replaced fittings to the FAA. <HD SOURCE="HD1">Costs of Compliance</HD> The FAA estimates that this AD, if adopted as proposed, would affect 42 helicopters of U.S. registry. The FAA estimates the following costs to comply with this proposed AD: <GPOTABLE COLS="5" OPTS="L2,nj,i1" CDEF="s100,r75,8,8,12"> <TTITLE>Estimated Costs</TTITLE> <CHED H="1">Action</CHED> <CHED H="1">Labor cost</CHED> Cost on U.S. operators </CHED> <ROW> <ENT I="01">Inspect RH forward transmission support beam fitting</ENT> <ENT>2 work-hours × $85 per hour = $170</ENT> <ENT>$0</ENT> <ENT>$170</ENT> <ENT>$7,140</ENT> </ROW> <ROW> <ENT I="01">Report previous repairs and replaced fittings</ENT> <ENT>1 work-hour × $85 per hour = $85</ENT> <ENT>0</ENT> <ENT>85</ENT> <ENT>3,570</ENT> </ROW> </GPOTABLE> The FAA has received no definitive data on which to base the cost estimates for the on-condition repairs specified in this proposed AD. <HD SOURCE="HD1">Paperwork Reduction Act</HD> A federal agency may not conduct or sponsor, and a person is not required to respond to, nor shall a person be subject to a penalty for failure to comply with a collection of information subject to the requirements of the Paperwork Reduction Act unless that collection of information displays a currently valid OMB Control Number. The OMB Control Number for this information collection is 2120-0056. Public reporting for this collection of information is estimated to be approximately 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing the collection of information. All responses to this collection of information are mandatory. Send comments regarding this burden estimate or any other aspect of this collection of information, including suggestions for reducing this burden, to: Information Collection Clearance Officer, Federal Aviation Administration, 10101 Hillwood Parkway, Fort Worth, TX 76177-1524. <HD SOURCE="HD1">Authority for This Rulemaking</HD> Title 49 of the United States Code specifies the FAA's authority to issue rules on aviation safety. Subtitle I, section 106, describes the authority of the FAA Administrator. Subtitle VII: Aviation Programs, describes in more detail the scope of the Agency's authority. The FAA is issuing this rulemaking under the authority described in Subtitle VII, Part A, Subpart III, Section 44701: General requirements. Under that section, Congress charges the FAA with promoting safe flight of civil aircraft in air commerce by prescribing regulations for practices, methods, and procedures the Administrator finds necessary for safety in air commerce. This regulation is within the scope of that authority because it addresses an unsafe condition that is likely to exist or develop on products identified in this rulemaking action. <HD SOURCE="HD1">Regulatory Findings</HD> The FAA determined that this proposed AD would not have federalism implications under Executive Order 13132. This proposed AD would not have a substantial direct effect on the States, on the relationship between the national government and the States, or on the distribution of power and responsibilities among the various levels of government. For the reasons discussed above, I certify this proposed regulation: (1) Is not a “significant regulatory action” under Executive Order 12866, (2) Would not affect intrastate aviation in Alaska, and (3) Would not have a significant economic impact, positive or negative, on a substantial number of small entities under the criteria of the Regulatory Flexibility Act. <LSTSUB> <HD SOURCE="HED">List of Subjects in 14 CFR Part 39</HD> Air transportation, Aircraft, Aviation safety, Incorporation by reference, Safety. </LSTSUB> <HD SOURCE="HD1">The Proposed Amendment</HD> Accordingly, under the authority delegated to me by the Administrator, the FAA proposes to amend 14 CFR part 39 as follows: <HD SOURCE="HED">PART 39—AIRWORTHINESS DIRECTIVES</HD> 1. The authority citation for part 39 continues to read as follows: <HD SOURCE="HED">Authority:</HD> 49 U.S.C. 106(g), 40113, 44701. <SECTIO ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ Preview showing 10k of 15k characters. Full document text is stored and available for version comparison. ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━