2026-19255: Airworthiness Directives; The Boeing Company Airplanes

Federal Register, Volume 91 Issue 181 (Monday, September 21, 2026) [Federal Register Volume 91, Number 181 (Monday, September 21, 2026)] [Proposed Rules] [Pages 59708-59711] From the Federal Register Online via the Government Publishing Office [www.gpo.gov] [FR Doc No: 2026-19255] ----------------------------------------------------------------------- DEPARTMENT OF TRANSPORTATION Federal Aviation Administration 14 CFR Part 39 [Docket No. FAA-2026-8811; Project Identifier AD-2025-01891-T] RIN 2120-AA64 Airworthiness Directives; The Boeing Company Airplanes

Agency

Federal Aviation Administration (FAA), DOT.

Action

Notice of proposed rulemaking (NPRM). -----------------------------------------------------------------------

Summary

The FAA proposes to adopt a new airworthiness directive (AD) for certain The Boeing Company Model 737-8, 737-9, and 737-8200 airplanes. This proposed AD was prompted by a report that bearings in the elevator buss assembly could have been installed incorrectly (including being installed without the application of sealant) during production. This proposed AD would require detailed inspections of the elevator buss assembly bearings and bearing housings for any crack and indication of sealant application, and applicable on-condition actions. The FAA is proposing this AD to address the unsafe condition on these products.

Dates

The FAA must receive comments on this proposed AD by November 5, 2026.

Addresses

You may send comments, using the procedures found in 14 CFR 11.43 and 11.45, by any of the following methods: Federal eRulemaking Portal: Go to regulations.gov. Follow the instructions for submitting comments. Fax: 202-493-2251. Mail: U.S. Department of Transportation, Docket Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue SE, Washington, DC 20590. Hand Delivery: Deliver to Mail address above between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. AD Docket: You may examine the AD docket at regulations.gov under Docket No. FAA-2026-8811; 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. Material Incorporated by Reference: For Boeing material identified in this proposed 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 myboeingfleet.com. 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 regulations.gov under Docket No. FAA-2026-8811.

For Further Information Contact

Raymond Vital, Aviation Safety Engineer, FAA, 2200 South 216th St., Des Moines, WA 98198; phone: 206- 231-3521; email: [email protected].

Supplementary Information

[[Page 59709]] 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-2026-8811; Project Identifier AD-2025-01891-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 this 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 NPRM. 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 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 Raymond Vital, Aviation Safety Engineer, FAA, 2200 South 216th St., Des Moines, WA 98198; phone: 206-231-3521; email: [email protected]. Any commentary that the FAA receives that is not specifically designated as CBI will be placed in the public docket for this rulemaking. Background The FAA has received a report indicating that bearings in the elevator buss assembly could have been installed incorrectly (including being installed without the application of sealant) during production. The elevator buss assembly is part of the elevator controls system and assists in the movement of the control columns. Improper installation of bearings could lead to cracking in the elevator buss assembly bearings and bearing housings, which could lead to premature failure of the elevator buss assembly crank arms. This condition, if not addressed, could impact elevator pitch control and affect continued safe flight and landing of the airplane. FAA's Determination The FAA is issuing this NPRM after determining that the unsafe condition described previously is likely to exist or develop on other products of the same type design. Material Incorporated by Reference Under 1 CFR Part 51 The FAA reviewed Boeing Alert Requirements Bulletin 737-27A1331 RB, dated December 17, 2025. This material specifies procedures for a detailed inspection of the elevator buss assembly bearings and bearing housings for any crack and indication of sealant application, and applicable on-condition actions. On-condition actions include doing a push-out load test of the elevator buss assembly bearings having part numbers (P/N) BACB10HY08CNJP, BACB10HY10CNJP, and BACB10JG12AZJ03G; and, depending on findings, replacing the elevator buss assembly with a new or serviceable elevator buss assembly, replacing any affected bearing with a new bearing, and repairing the elevator buss assembly at an affected location and doing a push-out load test of the elevator buss assembly bearings at all unaffected bearing locations. 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 NPRM This proposed AD would require accomplishing the actions specified in the material already described, except for any differences identified as exceptions in the regulatory text of this proposed AD. For information on the procedures and compliance times, see this material at regulations.gov under Docket No. FAA-2026-8811. Costs of Compliance The FAA estimates that this AD, if adopted as proposed, would affect 95 airplanes of U.S. registry. The FAA estimates the following costs to comply with this proposed AD: Estimated Costs ---------------------------------------------------------------------------------------------------------------- Cost per Cost on U.S. Action Labor cost Parts cost product operators ---------------------------------------------------------------------------------------------------------------- Inspect bearings......................... 23 work-hours x $85 per $0 $1,955 $185,725 hour = $1,955. ---------------------------------------------------------------------------------------------------------------- The FAA estimates the following costs to do any necessary replacements that would be required based on the results of the proposed inspection. The agency has no way of determining the number of aircraft that might need these replacements: On-Condition Costs ---------------------------------------------------------------------------------------------------------------- Cost per Action Labor cost Parts cost product ---------------------------------------------------------------------------------------------------------------- Push-out load test...................... 1 work-hour x $85 per hour = $0......................... $85 $85. Replace bearing, P/N BACB10HY08CNJP..... 3 work-hours x $85 per hour $850 per bearing........... 1,105 = $255 per bearing. Replace bearing, P/N BACB10HY10CNJP..... 3 work-hours x $85 per hour $915 per bearing........... 1,170 = $255 per bearing. Replace bearing, P/N BACB10JG12AZJ03G... 3 work-hours x $85 per hour $1,554 per bearing......... 1,809 = $255 per bearing. Replace elevator buss assembly.......... 3 work-hours x $85 per hour $98,241.................... 98,496 = $255. ---------------------------------------------------------------------------------------------------------------- * The FAA has received no definitive data on which to base the cost estimates for some of the on-condition repairs specified in this AD. [[Page 59710]] 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. List of Subjects in 14 CFR Part 39 Air transportation, Aircraft, Aviation safety, Incorporation by reference, Safety. The Proposed Amendment Accordingly, under the authority delegated to me by the Administrator, the FAA proposes to amend 14 CFR part 39 as follows: PART 39--AIRWORTHINESS DIRECTIVES 0