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 the ADDRESSES section. Include “Docket No. FAA-2025-0485; Project Identifier AD-2024-00670-A” 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 again revise the 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 SNPRM.

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 SNPRM 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 SNPRM, 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 SNPRM. Submissions containing CBI should be sent to Kelly Fichter, Aviation Safety Engineer, FAA, 701 Columbia Avenue, College Park, GA 30337. 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 issued AD 2021-22-12, Amendment 39-21785 (86 FR 60753, November 4, 2021) (AD 2021-22-12), for certain Honda Model HA-420 airplanes. AD 2021-22-12 requires removing and cleaning the inner diameter of the flap control pushrod assembly and repetitively applying corrosion inhibiting compound (CIC) to this area. The FAA issued AD 2021-22-12 to prevent failure of the flap control pushrod assembly, which, if not addressed, could result in uncontrolled and un-annunciated flap asymmetry with consequent loss of control of the airplane.

The FAA issued an NPRM to amend 14 CFR part 39 by adding an AD to supersede AD 2021-22-12 that would have applied to certain serial-numbered Honda Model HA-420 airplanes. The NPRM was published in the Federal Register on April 11, 2025 (90 FR 15426). The NPRM was prompted by a report that the flap pushrod assemblies are susceptible to corrosion, and the subsequent development of updated flap control pushrod assemblies that are more corrosion resistant and do not require repetitive CIC applications. In the NPRM, the FAA proposed to continue to require removing and cleaning the inner diameter of the flap control pushrod assembly and repetitively applying CIC to this area. ( printed page 60030) The NPRM also proposed to expand the applicability to include additional airplanes and require replacing the flap control pushrod assemblies with new corrosion-resistant flap control pushrod assemblies.

Actions Since the NPRM Was Issued

Since the FAA issued the NPRM, it was discovered that the updated outboard corrosion resistant pushrods could interfere with the mid flap drive arms when fully deployed. As a result of this finding, the manufacturer published updated service material that includes a modified design of the flap control pushrod assembly to prevent interference with adjacent parts. The FAA is proposing this AD to address the unsafe condition on these products.

Comments

The FAA received one comment on the NPRM from an individual. The commenter supported the NPRM without change.

FAA's Determination

The FAA is proposing this AD after determining the unsafe condition described previously is likely to exist or develop in other products of the same type design. Certain changes described above expand the scope of the NPRM. As a result, it is necessary to reopen the comment period to provide additional opportunity for the public to comment on this SNPRM.

Material Incorporated by Reference Under 1 CFR Part 51

The FAA reviewed Honda Aircraft Company Alert Service Bulletin No. SB-420-27-009, Revision B, dated August 5, 2025. This material specifies procedures for replacing the flap control pushrod assemblies with improved design flap control pushrod assemblies.

This proposed AD would also require Honda Aircraft Company Alert Service Bulletin No. SB-420-27-008, dated August 31, 2021, which the Director of the Federal Register approved for incorporation by reference as of November 19, 2021 (86 FR 60753, November 4, 2021).

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 SNPRM

This proposed AD would retain all of the requirements of AD 2021-22-12. This proposed AD would also expand the applicability to include additional airplanes and require replacing the flap control pushrod assemblies with new corrosion-resistant flap control pushrod assemblies as terminating action for the repetitive CIC applications required by AD 2021-22-12.

Costs of Compliance

The FAA estimates that this AD, if adopted as proposed, would affect 107 airplanes of U.S. registry.

The FAA estimates the following costs to comply with this proposed AD:

The FAA has included all known costs in its cost estimate. According to the manufacturer, however, some or all of the costs of this proposed 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

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.

The Proposed Amendment

Accordingly, under the authority delegated to me by the Administrator, the FAA proposes to amend 14 CFR part 39 as follows:

1. The authority citation for part 39 continues to read as follows:

Authority: 49 U.S.C. 106(g), 40113, 44701.

a. Removing Airworthiness Directive 2021-22-12, Amendment 39-21785 ( 86 FR 60753, November 4, 2021); and

b. Adding the following new airworthiness directive:

Honda Aircraft Company LLC: Docket No. FAA-2025-0485; Project Identifier AD-2024-00670-A. ( printed page 60031)

(a) Comments Due Date

The FAA must receive comments on this airworthiness directive (AD) by February 6, 2026.

(b) Affected ADs

This AD replaces AD 2021-22-12, Amendment 39-21785 (86 FR 60753, November 4, 2021) (AD 2021-22-12).

(c) Applicability

This AD applies to the following Honda Aircraft Company LLC Model HA-420 airplanes, certificated in any category:

(1) Group 1 airplanes: serial numbers 42000153 through 42000158 and 42000160 through 42000206; and

(2) Group 2 airplanes: serial numbers 42000211, 42000212, and 42000215 through 42000287.

(d) Subject

Joint Aircraft System Component (JASC) Code 2752, Trailing Edge Flap Actuator.

(e) Unsafe Condition

This AD was prompted by a report that the flap pushrod assemblies are susceptible to corrosion. The FAA is issuing this AD to prevent failure of the flap control pushrod assembly. The unsafe condition, if not addressed, could result in uncontrolled and un-annunciated flap asymmetry with consequent loss of control of the airplane.

(f) Compliance

Comply with this AD within the compliance times specified, unless already done.

(g) Retained Actions From AD 2021-22-12 for Group 1 Airplanes

(1) Within 90 days after November 19, 2021 (the effective date of AD 2021-22-12), or 18 months after issuance of the first standard certificate of airworthiness, whichever occurs later: Remove, clean, apply corrosion inhibiting compound (CIC) to, and reinstall the left and right inboard and outboard flap control pushrod assemblies by following steps (3) through (6) of the Accomplishment Instructions in Honda Aircraft Company Alert Service Bulletin No. SB-420-27-008, dated August 31, 2021.

(2) Within 90 days or 300 hours time-in-service (TIS), whichever occurs first after accomplishing the actions required by paragraph (g)(1) of this AD, and thereafter at intervals not to exceed 90 days or 300 hours TIS, whichever occurs first: Reapply CIC by following step (5)(a) through (c) of the Accomplishment Instructions in Honda Aircraft Company Alert Service Bulletin No. SB-420-27-008, dated August 31, 2021.

(h) New Required Actions for Group 1 and Group 2 Airplanes

(1) Within 2 years after the effective date of this AD, replace the flap control pushrod assemblies with redesigned (zero hours TIS) flap control pushrod assemblies in accordance with steps (3) through (5) of the Accomplishment Instructions in Honda Aircraft Company Alert Service Bulletin No. SB-420-27-009 Revision B, dated August 5, 2025.

(2) For Group 1 airplanes, accomplishing the replacement required by paragraph (h)(1) of this AD terminates the requirements of paragraphs (g)(1) and (2) of this AD.

(i) Installation Prohibition

As of the effective date of this AD, do not install on any airplane, an inboard or outboard flap control pushrod assembly part number that is identified in the Effectivity section of Honda Aircraft Company Alert Service Bulletin No. SB-420-27-009 Revision B, dated August 5, 2025.

(j) No Reporting Requirement

Although Honda Aircraft Company Alert Service Bulletin No. SB-420-27-008, dated August 31, 2021, and Alert Service Bulletin No. SB-420-27-009, Revision B, dated August 5, 2025, specify to submit certain information to the manufacturer, this AD does not include those requirements.

(k) 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 (l) 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 Required for Compliance (RC), the provisions of paragraphs (k)(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

(l) Additional Information

For more information about this AD, contact Kelly Fichter, Aviation Safety Engineer, FAA, 1701 Columbia Avenue, College Park, GA 30337; phone: (404) 474-5544; email: ecb-cos@faa.gov.

(m) 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.

(3) The following material was approved for IBR on [DATE 35 DAYS AFTER PUBLICATION OF THE FINAL RULE].

(i) Honda Aircraft Company Alert Service Bulletin No. SB-420-27-009, Revision B, dated August 5, 2025.

(ii) [Reserved]

(4) The following material was approved for IBR on November 19, 2021 (86 FR 60753, November 4, 2021).

(i) Honda Aircraft Company Alert Service Bulletin No. SB-420-27-008, dated August 31, 2021.

(ii) [Reserved]

(5) 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.

(6) 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.

(7) 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.