Airworthiness Directives; The Boeing Company Airplanes

<RULE> DEPARTMENT OF TRANSPORTATION <SUBAGY>Federal Aviation Administration</SUBAGY> <CFR>14 CFR Part 39</CFR> <DEPDOC>[Docket No. FAA-2025-0739; Project Identifier AD-2025-00196-T; Amendment 39-23177; AD 2025-21-05]</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> Final rule. <SUM> <HD SOURCE="HED">SUMMARY:</HD> The FAA is adopting a new airworthiness directive (AD) for all The Boeing Company Model 717-200 airplanes. This AD was prompted by a report of a nose landing gear-up landing caused by the failure of the upper lock link assembly. This AD requires repetitive inspections for cracking of the upper lock link assembly and applicable on-condition actions. The FAA is issuing this AD to address the unsafe condition on these products. </SUM> <EFFDATE> <HD SOURCE="HED">DATES:</HD> This AD is effective January 2, 2026. The Director of the Federal Register approved the incorporation by reference of a certain publication listed in this AD as of January 2, 2026. </EFFDATE> <HD SOURCE="HED">ADDRESSES:</HD> <E T="03">AD Docket:</E> You may examine the AD docket at <E T="03">regulations.gov</E> under Docket No. FAA-2025-0739; 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 final rule, any comments received, and other information. The address for Docket Operations is 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">Material Incorporated by Reference:</E> • For the Boeing material identified in this AD, contact Boeing Commercial Airplanes, Attention: Contractual & Data Services (C&DS), 2600 Westminster Blvd., MC 110-SK57, Seal Beach, CA 90740-5600; telephone 562-797-1717; website <E T="03">myboeingfleet.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. It is also available at <E T="03">regulations.gov</E> under Docket No. FAA-2025-0739. <FURINF> <HD SOURCE="HED">FOR FURTHER INFORMATION CONTACT:</HD> Wayne Ha, Aviation Safety Engineer, FAA, 2200 South 216th St., Des Moines, WA 98198; phone: 562-627-5238; email: <E T="03">wayne.ha@faa.gov.</E> </FURINF> <SUPLINF> <HD SOURCE="HED">SUPPLEMENTARY INFORMATION:</HD> <HD SOURCE="HD1">Background</HD> The FAA issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 by adding an AD that would apply to all The Boeing Company Model 717-200 airplanes. The NPRM was published in the <E T="04">Federal Register</E> on April 29, 2025 (90 FR 17746). The NPRM was prompted by a report of a nose landing gear-up landing caused by the failure of the upper lock link assembly. In the NPRM, the FAA proposed to require repetitive inspections for cracking of the upper lock link assembly and applicable on-condition actions. The FAA is issuing this AD to address a failure of the upper lock link assembly caused by non-conforming surface roughness, due to tool marks on the surface. The unsafe condition, if not addressed, could result in a failure of the nose landing gear (NLG) to fully extend during landing or cause the nose gear to remain retracted while the main gear deploys. Additionally, it could restrict ground maneuverability, increasing the risk of a runway excursion. <HD SOURCE="HD1">Discussion of Final Airworthiness Directive</HD> <HD SOURCE="HD1">Comments</HD> The FAA received comments from the Air Line Pilots Association, International (ALPA) and Boeing who supported the NPRM without change. The FAA received additional comments from Delta Air Lines (Delta) and an anonymous commenter. The following presents those comments and the FAA's response. <HD SOURCE="HD1">Request To Exclude Newly Manufactured Parts</HD> Delta requested that the FAA add an exception to paragraph (h) of the proposed AD to exclude from the overhaul requirement upper lock link assemblies manufactured after a specific date. Delta stated that Boeing Alert Requirements Bulletin 717-32A0043 RB, dated February 12, 2025, specifies overhauling all upper lock link assemblies, including newly manufactured parts. Delta claimed that overhaul of new parts places a significant burden on operators, particularly those relying on third-party vendors for overhaul services. Delta also expressed concern that this action implies newly manufactured parts are still being manufactured and delivered with the known defect. However, if the part defect has been addressed in production, Delta stated new parts produced after a specific date determined by the manufacturer should be exempted from the overhaul requirement. The FAA acknowledges the request. After consultation with the parts manufacturer, the FAA has determined that upper lock link assemblies manufactured after December 31, 2001, are serviceable upper lock link assemblies and therefore should be exempt from the overhaul requirement. Accordingly, the FAA has added paragraphs (h)(2) and (3) of this AD to exclude airplanes with an upper lock link assembly manufactured after December 31, 2001, from the requirements of this AD. <HD SOURCE="HD1">Request To Expand the Definition of Serviceable Upper Lock Link Assembly</HD> Delta requested that the FAA add an exception to paragraph (h) of the proposed AD to expand the definition of a serviceable upper lock link assembly to include parts that were manufactured after a specific date determined by the manufacturer. As discussed in the previous comment, Delta stated that the part defect may have been addressed in production, and these new parts should be included in the definition of a serviceable upper lock link assembly. Delta stated that note (a) of table 1 defines a serviceable part solely as one that has been overhauled in accordance with a certain overhaul manual. The FAA agrees with the request for the reasons provided in the previous comment. Accordingly, the FAA has added paragraph (h)(4) to include upper lock link assemblies manufactured after December 31, 2001, in the definition of a serviceable upper lock link assembly. <HD SOURCE="HD1">Request To Allow Installation of a Non-Overhauled Part</HD> Delta noted that table 1, condition 1 of Boeing Alert Requirements Bulletin 717-32A0043 RB, dated February 12, 2025, specifies installing a serviceable upper lock link assembly ( <E T="03">i.e.,</E> one that has been overhauled in accordance with a certain overhaul manual) before further flight if any crack is found as a result of the eddy current high frequency (ETHF) inspection. Delta requested the FAA add an exception to paragraph (h) of the proposed AD to provide an option to table 1, condition 1 (in case a crack is found) that instead allows installation of an upper lock link assembly that has not been overhauled in accordance with a certain overhaul manual but has complied with the initial ETHF inspection. Delta suggested that an upper lock link assembly that has been inspected by the ETHF inspection should be considered acceptable for installation because it is being tracked to comply with the repetitive inspection interval every 4,800 flight cycles. Delta asserted that this approach would maintain an equivalent level of safety while offering operators greater flexibility. The FAA infers that Delta is requesting that the FAA revise the AD to allow installation of an upper lock link assembly that has not been overhauled in accordance with the overhaul manual referenced in the requirements bulletin but on which the ETHF inspection has been accomplished with no crack found. The FAA agrees with this request. The FAA has determined that, in this case, the affected upper lock link assembly is being tracked and maintained in accordance with the required repetitive ETHF inspection interval, and that this approach maintains an equivalent level of safety. The FAA has not changed the AD in this regard because installation of a non-overhauled part is already acceptable under table 1, condition 2, option 1 of the requirements bulletin. <HD SOURCE="HD1">Request To Reduce the Repetitive Inspection Interval</HD> An anonymous commenter requested that the FAA revise the proposed AD to require more frequent inspections, especially for aircraft with high cycle counts. The commenter asserted that the proposed inspection requirements do not address the serious safety risk of the nose gear-up landing incident that prompted the proposed AD. The FAA disagrees with reducing the repetitive inspection interval. The safety concern of this AD is not related to the number of airplane cycles. The root cause of the upper lock link assembly failure was non-conforming surface roughness from tool marks. The referenced service information in this AD outlines procedures for repetitive ETHF inspections of both the top and bottom surfaces of the upper lock link assembly to detect any cracks and specifies replacement of any cracked assemblies with serviceable ones. The repetitive inspection interval of 4,800 cycles was calculated by crack growth analysis and was correlated to the striation count data in the National Transportation Safety Board (NTSB) lab report. The required inspection interval allows for two inspection opportunities between crack detectability and instability. The FAA did not change this AD in response to this comment. <HD SOURCE="HD1">Request To Require Immediate Replacement of the Affected Parts</HD> An anonymous commenter requested that the FAA revise the proposed AD to require immediate replacement of all upper lock link assemblies manufactured during the same production period as th ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ Preview showing 10k of 22k characters. Full document text is stored and available for version comparison. ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━