Airworthiness Directives; The Boeing Company Airplanes

DEPARTMENT OF TRANSPORTATION <SUBAGY>Federal Aviation Administration</SUBAGY> <CFR>14 CFR Part 39</CFR> <DEPDOC>[Docket No. FAA-2026-0023; Project Identifier AD-2025-00427-T]</DEPDOC> <RIN>RIN 2120-AA64</RIN> <SUBJECT>Airworthiness Directives; The Boeing Company Airplanes</SUBJECT> <HD SOURCE="HED">AGENCY:</HD> Federal Aviation Administration (FAA), DOT. <HD SOURCE="HED">ACTION:</HD> Notice of proposed rulemaking (NPRM). <SUM> <HD SOURCE="HED">SUMMARY:</HD> The FAA proposes to supersede Airworthiness Directive (AD) 2018-11-14, which applies to certain The Boeing Company Model 767-300 and -300F series airplanes. AD 2018-11-14 requires high frequency eddy current (HFEC) inspections for cracking of the lower outboard wing skin, and repair or modification if necessary. AD 2018-11-14 also requires one of three follow-on actions: Repeating the HFEC inspections, modifying certain internal stringers and oversizing and plugging the existing fastener holes of the lower wing or modifying the external doubler/tripler and doing repetitive post-modification inspections. Since the FAA issued AD 2018-11-14, it was determined that, for certain airplanes, the area of the lower wing skin in the vicinity of the critical inboard end fasteners of installed repair doublers must be inspected. In addition, it was determined that airplanes who have installed Supplemental Type Certificate (STC) ST01920SE and removed the STC winglets are also affected by the unsafe condition. This proposed AD would continue to require the actions in AD 2018-11-14, add airplanes to the applicability who have installed STC ST01920SE and removed the STC winglets, and, for certain airplanes, would require repetitive internal and external HFEC inspections of the lower outboard wing skin common to the external doubler repair at stringer L-9.5 and repair if necessary. The FAA is proposing this AD to address the unsafe condition on these products. </SUM> <DATES> <HD SOURCE="HED">DATES:</HD> The FAA must receive comments on this proposed AD by March 12, 2026. </DATES> <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-2026-0023; 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. <E T="03">Material Incorporated by Reference:</E> • For Aviation Partners Boeing material identified in this proposed AD, contact Aviation Partners Boeing, 2811 South 102nd St., Suite 200, Seattle, WA 98168; telephone 206-830-7699; email <E T="03">certification@aviationpartners.com;</E> website <E T="03">aviationpartnersboeing.com</E> . • You may view this material at the FAA, Airworthiness Products Section, Operational Safety Branch, 2200 South 216th St., Des Moines, WA. For information on the availability of this material at the FAA, call 206-231-3195. <FURINF> <HD SOURCE="HED">FOR FURTHER INFORMATION CONTACT:</HD> Sarah Illg, Aviation Safety Engineer, FAA, 3960 Paramount Boulevard, Lakewood, CA 90712; phone: 206-231-3517; email: <E T="03">Sarah.A.Illg@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 relevant data, views, or arguments about this proposal. Send your comments using a method listed under the <E T="02">ADDRESSES</E> section. Include “Docket No. FAA-2026-0023; Project Identifier AD-2025-00427-T” 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 amend 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 <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 proposed AD. <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 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 Sarah Illg, Aviation Safety Engineer, FAA, 3960 Paramount Boulevard, Lakewood, CA 90712; phone: 206-231-3517; email: <E T="03">Sarah.A.Illg@faa.gov.</E> Any commentary that the FAA receives that 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 2018-11-14, Amendment 39-19302 (83 FR 25885, June 5, 2018) (AD 2018-11-14), for certain The Boeing Company Model 767-300 and -300F series airplanes. AD 2018-11-14 was prompted by reports of fatigue cracking in the lower outboard wing skin at the inboard fastener of stringer L-9.5, and the lower outboard wing skin of stringer L-6.5, on airplanes with winglets installed per STC ST01920SE. AD 2018-11-14 requires HFEC inspections for cracking of the lower outboard wing skin, and repair or modification if necessary. AD 2018-11-14 also requires one of three follow-on actions: Repeating the HFEC inspections, modifying certain internal stringers and oversizing and plugging the existing fastener holes of the lower wing, or modifying the external doubler/tripler and doing repetitive post-modification inspections. The FAA issued AD 2018-11-14 to prevent fatigue cracking in the lower outboard wing skin, which could result in failure and subsequent separation of the wing and winglet and consequent reduced controllability of the airplane. <HD SOURCE="HD1">Actions Since AD 2018-11-14 Was Issued</HD> Since the FAA issued AD 2018-11-14, an operator found cracks in the lower wing skin during a post-repair inspection of an affected airplane. The post-repair inspection was an external surface HFEC inspection and was not mandated by AD 2018-11-14, which refers to Aviation Partners Boeing Service Bulletin AP767-57-010, Revision 11, dated April 3, 2017, as the appropriate source of service information for accomplishing certain inspections. The area of the lower wing skin in the vicinity of the critical inboard end fasteners of previously installed repair doublers, approved by the Boeing Commercial Airplanes Organization Designation Authorization (ODA) and prior to the issuance of the Aviation Partners Boeing Service Bulletin AP767-57-010, Revision 11, dated April 3, 2017, was inadvertently omitted from the internal HFEC inspection, for Group 3 airplanes, specified in Aviation Partners Boeing Service Bulletin AP767-57-010, Revision 11, dated April 3, 2017, and could result in the inadequate opportunity of crack detection at the critical fasteners. The FAA determined that, for certain airplanes, the area of the lower wing skin in the vicinity of the critical inboard end fasteners of installed repair doublers must be inspected in order to address the unsafe condition. Aviation Partners Boeing issued Service Bulletin AP767-57-010, Revision 14, dated November 17, 2025, to add the inspections at the critical inboard end fasteners of installed repair doublers for Group 3 airplanes, and add one additional airplane to the list of affected Group 3 airplanes. In addition, the FAA determined that airplanes that have ever been modified by STC ST01920SE are affected by the unsafe condition but not all airplanes that were modified by STC ST01920SE were identified in the applicability of AD 2018-11-14. AD 2018-11-14 identified airplanes “with Aviation Partners Boeing winglets installed; as identified in Aviation Partners Boeing Service Bulletin AP767-57-010, Revision 11, dated April 3, 2017; and Aviation Partners Boeing Service Bulletin AP767-57-014, Revision 1, dated April 12, 2017. However, operators who have modified their airplanes via STC ST01920SE and have removed the STC winglets are also applicable. Although the “Effectivity” of Aviation Partners Boeing Service Bulletin AP767-57-010, Revision 11, dated April 3, 2017; and Aviation Partners Boeing Service Bulletin AP767-57-014, Revision 1, dated April 12, 2017, only specify “airplanes with blended winglets,” the bulletins also apply to the Group 1, 2, and 3 airplanes who have installed STC ST01920SE and removed the STC winglets. The FAA has revised the applicability of this proposed AD to refer to new Aviation Partners Boeing service bulleti ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ Preview showing 10k of 71k characters. Full document text is stored and available for version comparison. ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━