Background The FAA issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 by adding an AD that would apply to certain Honda Model HA-420 airplanes. The NPRM was published in the Federal Register on July 7, 2025 (90 FR 29804). The NPRM was prompted by a production quality assurance inspection that revealed a gap between the trailing edge wing nut plates and leading edge aileron balance weights with less than the minimum required clearance. This reduction could result in jamming or contact between the balance weights and the nut plates and could negatively affect flight and cause damage to the airplane. The unsafe condition, if not addressed, could result in loss of control of the airplane. In the NPRM, the FAA proposed to require replacing the affected left and right aileron fixed balance weights with reduced geometry fixed balance weights. The FAA is issuing this AD to address the unsafe condition on these products. Discussion of Final Airworthiness Directive Comments The FAA received comments from one commenter. The commenter was Honda. The following presents the comments received on the NPRM and the FAA's response to each comment. Request To Revise the Background Paragraph and Unsafe Condition Honda requested that the FAA remove the mention of potential jamming between the wing trailing edge nut plates and aileron leading edge balance weights from the Background paragraph of the proposed AD and revise the paragraph to read; "This reduction could result in contact between the balance weights and nut plates, if not addressed causing damage to the airplane." Honda also requested that the FAA remove mention of potential jamming and loss of control of the airplane from paragraph (e) of the proposed AD, and revise the unsafe condition to read; "The FAA is issuing this AD to prevent contact between the balance weights and the nut plates. The unsafe condition, if not addressed, could result in damage to the airplane." Honda noted that prior to every flight in service, the pilot verifies that all flight controls are "free and correct," and if ailerons have the potential to bind, the condition would be caught during these flight control checks. Honda also noted that multiple aileron travel checks did not result in reports of interference or jamming on numerous potentially affected airplanes and the risk of jamming is not substantiated by operational data. The FAA disagrees with the request to revise the Background language because there is still a potential of jamming or interference between the balance weights and nut plates at maximum aileron deflection during landing or mid-flight. The FAA notes that the reduced gap condition still existed in 10 affected airplanes, and there is not enough substantiated data to show any mitigation effect to the jamming or interference at maximum aileron deflection. The FAA has not changed this AD based on this request. Request To Revise Paragraph (g) "Required Actions" Honda requested that the FAA revise paragraph (g) of the proposed AD, so that before further flight replacement of the balance weights would only be necessary if interference is found during the clearance check. The commenter stated that the use of "before further flight" is not warranted based on Honda's safety risk assessment since multiple aileron travel checks did not result in reports of interference or jamming on numerous potentially affected airplanes and the risk of jamming is not substantiated by operational data. Honda also stated that its requested approach would align with Honda's safety risk assessment and operational experience, and allow for a targeted response based on actual findings rather than a blanket requirement that Honda said may not be necessary. Honda also argued that paragraph (g)(3) of the proposed AD is not warranted and would only cause delays for completion of this action because Honda has FAA-approved data that allows use of the larger balance weights having part number (P/N) HJ1-15751-137-005, but chose not to include the larger adjustable weight part number in the parts list of the service bulletin in order to track utilization of the longer weights. The instructions to install them are in step (5) Accomplishment Instructions of the Service Bulletin. Further, the FAA notes that the reduced gap condition still existed in 10 out of 38 affected airplanes. Even if these 10 airplanes had the aileron checks done on the issue date of Honda Aircraft Company Service Bulletin No. SB-420-27-011, Revision B, dated December 12, 2024, they still require replacement of the affected left and right aileron fixed balance weights with reduced geometry fixed balance weights before further flight after the effective date of this AD. Prolonging this unsafe condition for another 60 days would introduce additional unnecessary safety risk, and there is not substantiated data to show any mitigation effect to the jamming or interference at maximum aileron deflection. The FAA also notes that it is important to ensure that the ailerons are properly balanced with the appropriate configuration under an FAA-approved procedure, especially when a mixed combination and order between different types of balance weight can introduce further complications and complexity. The FAA has not changed this AD based on this request. Request To Remove "Differences Between This Proposed AD and the Reference Material" Paragraph Honda requested that the FAA remove the "Differences Between This Proposed AD and the Reference Material" paragraph from the proposed AD. The commenter noted that Honda already uses FAA-approved data that allows for use of the larger balance weights having P/N HJ1-15751-137-005, and the information currently in the Differences paragraph of the proposed AD would cause unnecessary delays. The FAA disagrees with the request. The FAA acknowledges that Honda uses FAA-approved data allowing for use of larger balance weights having P/N HJ1-15751-137-005, but the process for installation of the balance weight is not appropriately highlighted and detailed in Honda Aircraft Company Service Bulletin No. SB-420-27-011, Revision B, dated December 12, 2024. The FAA also notes that it is important to ensure that the ailerons are properly balanced with the appropriate configuration under an FAA-approved procedure, especially when a mixed combination and order between different types of balance weights can introduce further complications and complexity. The FAA has not changed this AD based on this request. Conclusion The FAA reviewed the relevant data, considered any comments received, and determined that air safety requires adopting this AD as proposed. Accordingly, the FAA is issuing this AD to address the unsafe condition on these products. Except for minor editorial changes, this AD is adopted as proposed in the NPRM. None of the changes will increase the economic burden on any operator. Material Incorporated by Reference Under 1 CFR Part 51 The FAA reviewed Honda Aircraft Company Service Bulletin No. SB-420-27-011, Revision B, dated December 12, 2024. This material specifies procedures for replacing the affected left and right aileron fixed balance weights with reduced geometry fixed balance weights to ensure the minimum required clearances are maintained with the adjacent wing trailing edge panel fasteners. 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. Differences Between This AD and the Referenced Material Honda Aircraft Company Service Bulletin No. SB-420-27-011, Revision B, dated December 12, 2024, specifies contacting Honda if proper aileron balance cannot be attained using adjustable balance weights, but this AD requires using a procedure approved by the Manager, East Certification Branch, FAA. Costs of Compliance The FAA estimates that this AD affects 38 airplanes of U.S. registry. The FAA estimates the following costs to comply with this AD: Estimated Costs Action Labor cost Parts cost Cost per product Cost on U.S. operators Replace the left and right inboard and outboard fixed balance weights 45 work-hours × $85 per hour = $3,825 $3,676 $7,501 $285,038 The instructions for repair could vary significantly from airplane to airplane if proper aileron balance cannot be attained using adjustable balance weights. The FAA has no way of determining the cost of this repair or the number of airplanes that may require repair. The FAA has included all known costs in its cost estimate. According to the manufacturer, however, some of the costs of this AD may be covered under warranty, thereby reducing the cost impact on affected operators. 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 that authority because it addresses an unsafe condition that is likely to exist or develop on products identified in this rulemaking action. Regulatory Findings This AD will not have federalism implications under Executive Order 13132. This AD will 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 that this AD: (1) Is not a "significant regulatory action" under Executive Order 12866, (2) Will not affect intrastate aviation in Alaska, and (3) Will 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 Amendment Accordingly, under the authority delegated to me by the Administrator, the FAA amends 14 CFR part 39 as follows: PART 39-AIRWORTHINESS DIRECTIVES 1. The authority citation for part 39 continues to read as follows: Authority: 49 U.S.C. 106(g), 40113, 44701. § 39.13 [Amended] 2. The FAA amends § 39.13 by adding the following new airworthiness directive: 2026-01-01 Honda Aircraft Company LLC: Amendment 39-23229; Docket No. FAA-2025-1355; Project Identifier AD-2025-00016-A. (a) Effective Date This airworthiness directive (AD) is effective February 17, 2026. (b) Affected ADs None. (c) Applicability This AD applies to Honda Aircraft Company LLC (Honda) Model HA-420 airplanes, serial numbers 42000172, 42000235 through 42000265, and 42000267 through 42000272, certificated in any category, with aileron balance weight part number HJ1-15751-152-003 or HJ1-15751-157-003 installed. (d) Subject Joint Aircraft System Component (JASC) Code 2710, Aileron Control System. (e) Unsafe Condition This AD was prompted by the discovery that the gap between the trailing edge wing nut plates and leading edge aileron balance weights may be less than the minimum required clearance. The FAA is issuing this AD to prevent jamming or contact between the balance weights and the nut plates. The unsafe condition, if not addressed, could result in loss of control of the airplane. (f) Compliance Comply with this AD within the compliance times specified, unless already done. (g) Required Actions Before further flight after the effective date of this AD, replace the left and right aileron fixed balance weights in accordance with steps 3.0(3) through 3.0(8) of the Accomplishment Instructions in Honda Aircraft Company Service Bulletin No. SB-420-27-011, Revision B, dated December 12, 2024, except as provided in paragraphs (g)(1) through (3) of this AD. (1) Instead of discarding parts, you must remove those parts from service. (2) This AD does not require returning parts to the manufacturer. (3) Instead of contacting Honda if proper aileron balance cannot be attained using adjustable balance weights, this AD requires attaining proper aileron balance using a procedure approved by the Manager, East Certification Branch, FAA. (h) Alternative Methods of Compliance (AMOCs) (1) The Manager, East 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 East Certification Branch, send it to the attention of the person identified in paragraph (i) of this AD and email 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. (3) For material that contains steps that are labeled as RC the provisions of paragraphs (h)(3)(i) and (ii) of this AD apply. (i) The steps labeled as RC, including substeps under an RC step and any figures identified in an RC step, must be done to comply with the AD. An AMOC is required for any deviations to RC steps, including substeps and identified figures. (ii) Steps not labeled as RC may be deviated from using accepted methods in accordance with the operator's maintenance or inspection program without obtaining approval of an AMOC, provided the RC steps, including substeps and identified figures, can still be done as specified, and the airplane can be put back in an airworthy condition. (i) Additional Information For more information about this AD, contact Tuan Tran, Aviation Safety Engineer, FAA, 1701 Columbia Avenue, College Park, GA 30337; phone: (404) 474-5522; email: ECB-COS@faa.gov. (j) 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) Honda Aircraft Company Service Bulletin No. SB-420-27-011, Revision B, dated December 12, 2024. (ii) [Reserved] (3) For Honda Aircraft Company material identified in this AD, contact Honda Aircraft Company LLC, 6430 Ballinger Road, Greensboro, NC 27410; phone: (336) 662-0246; website: hondajet.com. (4) You may view this material at the FAA, Airworthiness Products Section, Operational Safety Branch, 901 Locust, Kansas City, MO 64106. 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 January 8, 2026. Steven W. Thompson, Acting Deputy Director, Compliance & Airworthiness Division, Aircraft Certification Service.