2026-18522: Airworthiness Directives; Bell Textron Canada Limited Helicopters

Federal Register, Volume 91 Issue 174 (Thursday, September 10, 2026) [Federal Register Volume 91, Number 174 (Thursday, September 10, 2026)] [Proposed Rules] [Pages 57519-57521] From the Federal Register Online via the Government Publishing Office [www.gpo.gov] [FR Doc No: 2026-18522] ----------------------------------------------------------------------- DEPARTMENT OF TRANSPORTATION Federal Aviation Administration 14 CFR Part 39 [Docket No. FAA-2026-8796; Project Identifier AD-2026-00018-R] RIN 2120-AA64 Airworthiness Directives; Bell Textron Canada Limited Helicopters

Agency

Federal Aviation Administration (FAA), DOT.

Action

Notice of proposed rulemaking (NPRM). -----------------------------------------------------------------------

Summary

The FAA proposes to adopt a new airworthiness directive (AD) for all Bell Textron Canada Limited (Bell) Model 206L, 206L-1, 206L-3, and 206L-4 helicopters with FAA Supplemental Type Certificate (STC) SR02684LA installed. This proposed AD was prompted by an event where a Bell Model 206L helicopter with FAA STC SR02684LA installed experienced moderate to severe vertical vibration, which resulted in damage to the tail boom of the helicopter. This proposed AD would require revising the Limitations section of the existing rotorcraft flight manual (RFM) for the helicopter to include a never-exceed-speed (VNE) limitation and would require incorporating a rotorcraft flight manual supplement (RFMS) into the existing RFM. The FAA is proposing this AD to address the unsafe condition on these products.

Dates

The FAA must receive comments on this proposed AD by October 26, 2026.

Addresses

You may send comments, using the procedures found in 14 CFR 11.43 and 11.45, by any of the following methods: Federal eRulemaking Portal: Go to regulations.gov. Follow the instructions for submitting comments. Fax: (202) 493-2251. Mail: U.S. Department of Transportation, Docket Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue SE, Washington, DC 20590. Hand Delivery: Deliver to Mail address above between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. AD Docket: You may examine the AD docket at regulations.gov under Docket No. FAA-2026-8796; 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. Material Incorporated by Reference: For Van Horn Aviation, L.L.C. material identified in this proposed AD, contact Van Horn Aviation, LLC, 1510 West Drake Drive, Tempe, AZ 85283; phone: (480) 483-4202; email: [email protected]. You may view this material at the FAA, Airworthiness Products Section, Operational Safety Branch, 10101 Hillwood Parkway, Fort Worth, TX 76177. For information on the availability of this material at the FAA, call (817) 222-5110.

For Further Information Contact

James Guo, Aviation Safety Engineer, FAA, 3960 Paramount Boulevard, Lakewood, CA 90712; phone: (562) 627- 5357; email: [email protected].

Supplementary Information

Comments Invited The FAA invites you to send any written relevant data, views, or arguments about this proposal. Send your comments using a method listed under ADDRESSES. Include ``Docket No. FAA-2026-8796; Project Identifier AD-2026-00018-R'' at the beginning of your [[Page 57520]] 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 regulations.gov, including any personal information you provide. The agency will also post a report summarizing each substantive verbal contact received about this NPRM. Confidential Business Information 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 James Guo, 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. Background The FAA received a report of an event involving a Model 206L helicopter with Van Horn Aviation main rotor blades, part number 20633000-101. These blades were approved for installation through FAA STC SR02684LA. During this event, the helicopter experienced an unexpected moderate-to-severe vertical vibration during flight. Due to the unexpected vibration, the pilot initially lowered the collective to begin a descent. Subsequently, when the pilot raised the collective and initiated a left turn, the vibration diminished. The pilot was able to complete a landing without further incident; however, post-flight inspection revealed that the helicopter had sustained tail boom damage. Due to this event, the manufacturer issued material that includes accomplishing existing maintenance actions that may help reduce the likelihood of this unsafe condition. The root cause for the vibration is still being investigated. Due to risk analysis based on historical events and ongoing investigation, the FAA has determined that this proposed interim AD is necessary to mitigate risk. This condition, if not addressed, could result in structural damage to the aircraft and loss of control of the helicopter. FAA's Determination 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. Material Incorporated by Reference Under 1 CFR Part 51 The FAA reviewed Van Horn Aviation, L.L.C. Rotorcraft Flight Manual Supplement, Document No. 206L-MR-FMS-101, Revision 0, dated March 25, 2026 (VHA RFMS). This material specifies procedures to accomplish in the event of an unexpected moderate-to-severe vibration during flight. 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 ADDRESSES section. Proposed AD Requirements in This NPRM This proposed AD would require revising the existing RFM for the helicopter to include revising the Limitations section to include a text stating a VNE limitation based on gross weight. This proposed AD would also require revising the existing RFM for the helicopter by incorporating the VHA RFMS. The owner/operator (pilot) holding at least a private pilot certificate may revise the existing RFM for the helicopter and must enter compliance into the helicopter maintenance records in accordance with 14 CFR 43.9(a) and 91.417(a)(2)(v). The pilot may perform this action because it only involves revising the RFM, which could be performed equally well by a pilot or a mechanic. This is an exception to the FAA's standard maintenance regulations. Differences Between This Proposed AD and the Referenced Material Where the material in Section 1, ``Limitations,'' of the VHA RFMS specifies ``No Limitations,'' this proposed AD would require revising the RFM to also include a VNE limitation based on gross weight. Due to risk analysis based on historical events and ongoing investigation, the FAA has determined that this VNE limitation is necessary to mitigate risk. Interim Action The FAA considers that this proposed AD would be an interim action. If further action is later identified, the FAA might consider further rulemaking. Costs of Compliance The FAA estimates that this AD, if adopted as proposed, would affect 200 helicopters of U.S. registry. The FAA estimates the following costs to comply with this proposed AD: Estimated Costs ---------------------------------------------------------------------------------------------------------------- Cost per Cost on U.S. Action Labor cost Parts cost product operators ---------------------------------------------------------------------------------------------------------------- Revise the RFM........................ 1 work-hour x $85 per $0 $85 $17,000 hour = $85. ---------------------------------------------------------------------------------------------------------------- Authority for This Rulemaking 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 [[Page 57521]] that authority because it addresses an unsafe condition that is likely to exist or develop on products identified in this rulemaking action. Regulatory Findings 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. List of Subjects in 14 CFR Part 39 Air transportation, Aircraft, Aviation safety, Incorporation by reference, Safety. The Proposed Amendment Accordingly, under the authority delegated to me by the Administrator, the FAA proposes to amend 14 CFR part 39 as follows: PART 39--AIRWORTHINESS DIRECTIVES 0