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Federal Register / Vol. 86, No. 211 / Thursday, November 4, 2021 / Rules and Regulations
welded tube center section of inboard and outboard assemblies. Later borescope inspections of the same airplane inside the welded tube section revealed pitting and discoloration of interior walls. On a later scheduled inspection of another airplane, similar corrosion was noted.
While the specific root cause of the corrosion is still under investigation, the flap control pushrods on the affected airplanes are susceptible to corrosion because the material of the pushrod is a low-alloy steel that had incomplete coverage of primer and CIC in the inner diameter. This incomplete coverage is potentially due to welding process spillover material creating voids that the primer could not reach and is exacerbated by general incomplete application. Drainage holes in the flap pushrod allow the external environment direct access to the inner diameter of the tube, exposing the improperly treated surface to the elements. As a result, corrosion may begin to develop immediately after the airplane enters service.
As a large majority of the fleet have been in service for longer than 12
months, during which time corrosion has progressed, the FAA finds the need for immediate action to preclude failure of the flap control pushrod. The compliance time of this AD prioritizes the affected fleet by risk and simultaneously requires all airplanes to be serviced as soon as possible.
Failure of a flap control pushrod, if not prevented, could result in uncontrolled and un-annunciated flap asymmetry, which could result in loss of control of the airplane. The FAA is issuing this AD to address the unsafe condition on these products.
FAAs Determination The FAA is issuing this AD because the agency has determined the unsafe condition described previously is likely to exist or develop in other products of the same type design.

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Related Service Information Under 1
CFR Part 51
The FAA reviewed Honda Aircraft Company Service Bulletin No. SB420
27008, dated August 31, 2021. This service information specifies procedures for removing and cleaning the inner diameter of the flap control pushrods and repetitively applying CIC to this area. This service information is reasonably available because the interested parties have access to it through their normal course of business or by the means identified in ADDRESSES.

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AD Requirements This AD requires accomplishing the actions specified in the service information already described.
Interim Action The FAA considers this AD to be an interim action. Honda is currently considering implementing design changes to preclude the need for repetitively applying CIC and more permanently address the unsafe condition identified in this AD. Once these design changes are developed, approved, and available, the FAA may consider additional rulemaking.
Justification for Immediate Adoption and Determination of the Effective Date Section 553b3B of the Administrative Procedure Act APA 5
U.S.C. 551 et seq. authorizes agencies to dispense with notice and comment procedures for rules when the agency, for good cause, finds that those procedures are impracticable, unnecessary, or contrary to the public interest. Under this section, an agency, upon finding good cause, may issue a final rule without providing notice and seeking comment prior to issuance.
Further, section 553d of the APA
authorizes agencies to make rules effective in less than thirty days, upon a finding of good cause.
An unsafe condition exists that requires the immediate adoption of this AD without providing an opportunity for public comments prior to adoption.
The FAA has found that the risk to the flying public justifies foregoing notice and comment prior to adoption of this rule because the corrosion reduces the fatigue life and potentially initiates cracks in the pushrod. Crack propagation in a steel part could lead to immediate failure, resulting in unannunciated, uncontrolled, and unrecoverable flap asymmetry. Because there is no primer or CIC on the affected part to prevent the corrosion from developing and worsening, the corrosion may appear immediately in service. As a large majority of the fleet has been in service for 12 to 24 months, during which time the corrosion has progressed, it is necessary to mitigate this unsafe condition by requiring the corroded pushrods to be serviced immediately. Also essential to correct the unsafe condition in the interim while a long term solution is developed is a requirement to reapply the CIC
every 90 days to prevent the corrosion from developing further. Accordingly, notice and opportunity for prior public comment are impracticable and contrary
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to the public interest pursuant to 5
U.S.C. 553b3B.
In addition, the FAA finds that good cause exists pursuant to 5 U.S.C. 553d for making this amendment effective in less than 30 days, for the same reasons the FAA found good cause to forego notice and comment.
Comments Invited The FAA invites you to send any written data, views, or arguments about this final rule. Send your comments to an address listed under ADDRESSES.
Include Docket No. FAA20210884
and Project Identifier AD202100998
A 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 https
www.regulations.gov, including any personal information you provide. The agency will also post a report summarizing each substantive verbal contact received about this final rule.
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 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 Samuel Kovitch, Aviation Safety Engineer, Atlanta ACO
Branch, FAA, 1701 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.
Regulatory Flexibility Act The requirements of the Regulatory Flexibility Act RFA do not apply when
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