Airworthiness Directives; Bell Textron Canada Limited Helicopters

<RULE> DEPARTMENT OF TRANSPORTATION <SUBAGY>Federal Aviation Administration</SUBAGY> <CFR>14 CFR Part 39</CFR> <DEPDOC>[Docket No. FAA-2025-3996; Project Identifier MCAI-2025-01201-R; Amendment 39-23181; AD 2025-22-03]</DEPDOC> <RIN>RIN 2120-AA64</RIN> <SUBJECT>Airworthiness Directives; Bell Textron Canada Limited Helicopters</SUBJECT> <HD SOURCE="HED">AGENCY:</HD> Federal Aviation Administration (FAA), DOT. <HD SOURCE="HED">ACTION:</HD> Final rule; request for comments. <SUM> <HD SOURCE="HED">SUMMARY:</HD> The FAA is superseding Airworthiness Directive (AD) 2025-06-51, which applied to certain Bell Textron Canada Limited (Bell) Model 505 helicopters. AD 2025-06-51 required removing all ballast weights from the aft movable ballast box assembly and prohibited the use of ballast weights within the aft movable ballast box assembly. Since the FAA issued AD 2025-06-51, Bell has developed a modification to the ballast box door assembly and the FAA has determined that the new actions would terminate the requirements of AD 2025-06-51. This AD requires installing the modification to the aft movable ballast box door assembly. The FAA is issuing this AD to address the unsafe condition on these products. </SUM> <EFFDATE> <HD SOURCE="HED">DATES:</HD> This AD is effective November 20, 2025. The Director of the Federal Register approved the incorporation by reference of a certain publication listed in this AD as of November 20, 2025. The FAA must receive comments on this AD by December 22, 2025. </EFFDATE> <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-2025-3996; 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 final rule, the mandatory continuing airworthiness information (MCAI), any comments received, and other information. The street address for Docket Operations is listed above. <E T="03">Material Incorporated by Reference:</E> • For Transport Canada material identified in this AD, contact Transport Canada, Transport Canada National Aircraft Certification, 159 Cleopatra Drive, Nepean, Ontario K1A 0N5, Canada; phone: (888) 663-3639; email: <E T="03">TC.AirworthinessDirectives-Consignesdenavigabilite.TC@tc.gc.ca.</E> You may view this material on the Transport Canada website at <E T="03">tc.canada.ca/en/aviation.</E> • You may view this material at the FAA, Office of the Regional Counsel, Southwest Region, 10101 Hillwood Parkway, Room 6N-321, Fort Worth, TX 76177. For information on the availability of this material at the FAA, call (817) 222-5110. It is also available at <E T="03">regulations.gov</E> under Docket No. FAA-2025-3996. <FURINF> <HD SOURCE="HED">FOR FURTHER INFORMATION CONTACT:</HD> Kurt Ladendorf, Aviation Safety Engineer, FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590; phone: (817) 222-5254; email: <E T="03">kurt.d.ladendorf@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 data, views, or arguments about this final rule. Send your comments using a method listed under the <E T="02">ADDRESSES</E> section. Include “Docket No. FAA-2025-3996; Project Identifier MCAI-2025-01201-R” at the beginning of your comments. The most helpful comments reference a specific portion of the final rule, explain the reason for any recommended change, and include supporting data. The FAA will consider all comments received by the closing date and may amend this final rule 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 final rule. <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 AD 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 AD, 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 AD. Submissions containing CBI should be sent to Kurt Ladendorf, Aviation Safety Engineer, FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590. 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 issued AD 2025-06-51, Amendment 39-23007 (90 FR 15310, April 10, 2025) (AD 2025-06-51), which was originally published as an Emergency AD dated March 21, 2025, for Bell Model 505 helicopters, serial numbers 65011 and subsequent with ballast kit part number (P/N) SLS-706-201-007 installed. AD 2025-06-51 was prompted by an MCAI originated by Transport Canada, which is the aviation authority for Canada. Transport Canada issued Emergency AD CF-2025-17, dated March 19, 2025, (Transport Canada Emergency AD CF-2025-17) to correct an unsafe condition identified as deformation and improper pin engagement in the knuckles of the door hinge on the aft movable ballast box assembly, which could allow the ballast weights to escape the ballast box and strike the tail rotor assembly. AD 2025-06-51 required removing all ballast weights from the aft movable ballast box assembly and prohibited the use of ballast weights within the aft movable ballast box assembly. The FAA issued AD 2025-06-51 to prevent damage and departure of tail rotor blades, loss of tail rotor thrust, and severe vibrations. The unsafe condition, if not addressed, could result in loss of control of the helicopter. <HD SOURCE="HD1">Actions Since AD 2025-06-51 Was Issued</HD> Since the FAA issued AD 2025-06-51, Transport Canada superseded Transport Canada Emergency AD CF-2025-17 and issued Transport Canada AD CF-2025-35, dated July 4, 2025 (Transport Canada AD 2025-35) (also referred to as the MCAI). The MCAI states the manufacturer has developed a modification to the ballast box door assembly which provides a terminating action for the prohibition from using ballast weights within the aft movable ballast box assembly. Also, the MCAI corrects an error in the ballast kit part number in the applicability section. The correct part number for the movable ballast kit is P/N SLS-706-201-001, instead of the aft movable ballast box assembly P/N SLS-706-201-007. The preamble to AD 2025-06-51 explained that the FAA considered the requirements “interim action” and was considering further rulemaking. The FAA has now determined that further rulemaking is indeed necessary, and this AD follows from that determination. You may examine the MCAI in the AD docket at <E T="03">regulations.gov</E> under Docket No. FAA-2025-3996. <HD SOURCE="HD1">Material Incorporated by Reference Under 1 CFR Part 51</HD> The FAA reviewed Transport Canada AD CF 2025-35, which specifies procedures for removing all ballast weights (P/N SLS-706-201-001) from the aft movable ballast box assembly (P/N SLS-706-201-007) and prohibits the use of ballast weights within the aft movable ballast box assembly. Transport Canada AD CF2025-35 also specifies installing a modification to the hinge of the aft movable ballast box door, by including a longer two-inch hinge assembly and adjusting the thickness of the rubber pad of the door assembly, which constitutes a terminating action for the prohibition of using ballast weights within the aft movable ballast box assembly. This material is reasonably available because the interested parties have access to it through their normal course of business or by the means identified in the <E T="02">ADDRESSES</E> section. <HD SOURCE="HD1">FAA's Determination</HD> These products have been approved by the civil aviation authority (CAA) of another country and are approved for operation in the United States. Pursuant to the FAA's bilateral agreement with this State of Design Authority, that authority has notified the FAA of the unsafe condition described in the MCAI referenced above. The FAA is issuing this AD 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">AD Requirements</HD> This AD requires accomplishing the actions specified Transport Canada CF-2025-35, described previously, as incorporated by reference, except for any differences identified as exceptions in the regulatory text of this AD. This includes requiring the actions of AD 2025-06-51 until the terminating action is done. The owner/operator (pilot) hol ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ Preview showing 10k of 22k characters. Full document text is stored and available for version comparison. ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━