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Federal Aviation Administration (FAA), DOT.
Notice of proposed rulemaking (NPRM).
The FAA proposes to supersede Airworthiness Directive (AD) 2019-20-07, which applies to all The Boeing Company Model 787-8, 787-9, and 787-10 airplanes. AD 2019-20-07 requires repetitive operational checks of the leading edge (LE) outboard (OB) slats and applicable on-condition actions. AD 2019-20-07 also requires revising the airplane flight manual (AFM) to prohibit flap retraction under icing conditions and revising the existing maintenance or inspection program, as applicable, to incorporate a new operation check. Since the FAA issued AD 2019-20-07, the manufacturer developed further actions to address the unsafe condition. This proposed AD would retain all requirements of AD 2019-20-07 and would require replacing the LE outboard geared rotary actuator (GRA) with a LE outboard lockout actuator (LEOLA) at leading edge OB slat locations and revising the existing maintenance or inspection program, as applicable, to incorporate a new certification maintenance requirement (CMR). This proposed AD would also remove airplanes from the applicability. The FAA is proposing this AD to address the unsafe condition on these products.
The FAA must receive comments on this proposed AD by May 4, 2026.
You may send comments, using the procedures found in 14 CFR 11.43 and 11.45, by any of the following methods:
AD Docket: You may examine the AD docket at regulations.gov under Docket No. FAA-2026-2712; 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:
Emanuel Chaves Torres, Aviation Safety Engineer, FAA, 2200 South 216th St., Des Moines, WA 98198; phone: 562-627-5350; email: emanuel.chaves.torres@faa.gov.
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-2026-2712; Project Identifier AD-2025-00931-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.
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 Emanuel Chaves Torres, Aviation Safety Engineer, FAA, 2200 South 216th St., Des Moines, WA 98198; phone: 562-627-5350; email: emanuel.chaves.torres@faa.gov. Any commentary that the FAA receives that is not specifically designated as CBI will be placed in the public docket for this rulemaking.
The FAA issued AD 2019-20-07, Amendment 39-19760 (84 FR 54765, October 11, 2019) (AD 2019-20-07), for all The Boeing Company Model 787-8, 787-9, and 787-10 airplanes. AD 2019-20-07 was prompted by a determination that the LE OB slat system could be out of position without flight deck annunciation. AD 2019-20-07 requires repetitive operational checks of the LE OB slats and applicable on-condition actions. AD 2019-20-07 also requires revising the AFM to prohibit flap retraction under icing conditions and revising the existing maintenance or inspection program, as applicable, to incorporate a new operation check. The agency issued AD 2019-20-07 to address a potential condition in which the LE OB slat system could be out of position without flight deck annunciation. This condition, if not addressed, could result in insufficient lift, resulting in inability to maintain continued safe flight and landing.
The preamble to AD 2019-20-07 specifies that the FAA considers that AD “interim action” and that the FAA may consider further rulemaking. Since the FAA issued AD 2019-20-07, the manufacturer has developed final actions to address the unsafe condition. The FAA has determined that these final actions must be required to address the unsafe condition and that accomplishing the final actions will terminate the requirements of AD 2019-20-07. The manufacturer has also incorporated these final actions on airplanes in production, which reduces the number of airplanes that would be affected by the unsafe condition.
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.
The FAA reviewed Boeing Alert Requirements Bulletin B787-81205-SB270055-00 RB, Issue 002, dated November 25, 2024. This material specifies procedures for replacing the LE outboard GRA with a LEOLA at leading edge slat 2 and slat 11 outboard locations and revising the operator's maintenance program to incorporate CMR document item 27-CMR-14, “Functionally check the Leading Edge Power Drive Unit Half System Torque Brake.”
This proposed AD would also require Boeing Alert Requirements Bulletin B787-81205-SB270051-00 RB, Issue 001, dated July 5, 2019, which the Director of the Federal Register approved for incorporation by reference as of October 11, 2019 (84 FR 54765, October 11, 2019).
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.
This proposed AD would retain all requirements of AD 2019-20-07. This proposed AD would remove airplanes from the applicability by specifying affected line numbers and require new actions that would terminate the requirements of AD 2019-20-07. This proposed AD would also 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-2026-2712.
The FAA estimates that this AD, if adopted as proposed, would affect 174 airplanes of U.S. registry. The FAA estimates the following costs to comply with this proposed AD: ( printed page 12944)
| Action | Labor cost | Parts cost | Cost per product | Cost on U.S. operators |
|---|---|---|---|---|
| Repetitive operational checks (retained actions from AD 2019-20-07) | 8 work-hours × $85 per hour = $680 per operational check | $0 | $680 per operational check | $118,320 per operational check. |
| AFM revision (retained action from AD 2019-20-07) | 1 work-hour × $85 per hour = $85 | 0 | $85 | $14,790. |
| Replacement (new proposed action) | 9 work-hours × $85 per hour = $765 | 31,610 | $32,375 | $5,633,250. |
| * Table does not include estimated costs for revising the existing maintenance or inspection program. | ||||
The FAA has determined that revising the existing maintenance or inspection program takes an average of 90 work-hours per operator, although the agency recognizes that this number may vary from operator to operator. Since operators incorporate maintenance or inspection program changes for their affected fleet(s), the FAA has determined that a per-operator estimate is more accurate than a per-airplane estimate. Therefore, the agency estimates the average total cost per operator to be $7,650 (90 work-hours × $85 per work-hour).
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.
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.
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.
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:
2. The FAA amends § 39.13 by:
a. Removing Airworthiness Directive (AD) 2019-20-07, Amendment 39-19760 ( 84 FR 54765, October 11, 2019), and
b. Adding the following new AD:
The Boeing Company: Docket No. FAA-2026-2712; Project Identifier AD-2025-00931-T.
The FAA must receive comments on this airworthiness directive (AD) by May 4, 2026.
This AD replaces AD 2019-20-07, Amendment 39-19760 (84 FR 54765, October 11, 2019) (AD 2019-20-07).
This AD applies to The Boeing Company Model 787-8, 787-9, and 787-10 airplanes, certificated in any category, as identified in Boeing Alert Requirements Bulletin B787-81205-SB270055-00 RB, Issue 002, dated November 25, 2024.
Air Transport Association (ATA) of America Code 27, Flight Controls.
This AD was prompted by a determination that the leading edge (LE) outboard (OB) slat system could be out of position without flight deck annunciation. The FAA is issuing this AD to address a potential condition in which the LE OB slat system could be out of position without flight deck annunciation. The unsafe condition, if not addressed, could result in insufficient lift, resulting in inability to maintain continued safe flight and landing.
Comply with this AD within the compliance times specified, unless already done.
This paragraph restates the requirements of paragraph (g) of AD 2019-20-07, with no changes. Except as specified by paragraph (h) of this AD: At the applicable times specified in the “Compliance” paragraph of Boeing Alert Requirements Bulletin B787-81205-SB270051-00 RB, Issue 001, dated July 5, 2019, do all applicable actions identified in, and in accordance with, the Accomplishment Instructions of Boeing Alert Requirements Bulletin B787-81205-SB270051-00 RB, Issue 001, dated July 5, 2019.
Note 1 to paragraph (g): Guidance for accomplishing the actions required by this AD can be found in Boeing Alert Service Bulletin B787-81205-SB270051-00, Issue 001, dated July 5, 2019, which is referred to in Boeing Alert Requirements Bulletin B787-81205-SB270051-00 RB, Issue 001, dated July 5, 2019.
This paragraph restates the requirements of paragraph (h) of AD 2019-20-07, with no changes. For purposes of determining compliance with the requirements of this AD: Where Boeing Alert Requirements Bulletin B787-81205-SB270051-00 RB, Issue 001, dated July 5, 2019, uses the phrase “the Issue 001 date of Requirements Bulletin B787-81205-SB270051-00 RB,” this AD requires using “October 11, 2019” (the effective date of AD 2019-20-07). ( printed page 12945)
This paragraph restates the requirements of paragraph (i) of AD 2019-20-07, with no changes. Within 60 days after October 11, 2019 (the effective date of AD 2019-20-07), revise the Limitations Section of the existing AFM to include the information in figure 1 to paragraph (i) of this AD. This may be done by inserting a copy of figure 1 to paragraph (i) of this AD into the Limitations Section of the existing AFM.
This paragraph restates the requirements of paragraph (j) of AD 2019-20-07, with no changes. Within 60 days after October 11, 2019 (the effective date of AD 2019-20-07), revise the existing maintenance or inspection program, as applicable, to incorporate the information specified in figure 2 to paragraph (j) of this AD. This may be done by inserting a copy of figure 2 to paragraph (j) of this AD into the existing maintenance or inspection program.
This paragraph restates the requirements of paragraph (k) of AD 2019-20-07, with no changes. After the existing maintenance or inspection program has been revised as required by paragraph (j) of this AD, no alternative actions ( e.g., inspections) or intervals may be used unless the actions or intervals are approved as an alternative method of compliance (AMOC) in accordance with the procedures specified in paragraph (p) of this AD.
Except as specified by paragraph (i) of this AD: At the applicable times specified in the “Compliance” paragraph of Boeing Alert Requirements Bulletin B787-81205-SB270055-00 RB, Issue 002, dated November 25, 2024, do all applicable actions identified in, and in accordance with, the Accomplishment Instructions of Boeing Alert Requirements Bulletin B787-81205-SB270055-00 RB, Issue 002, dated November 25, 2024.
Note 2 to paragraph (l): Guidance for accomplishing the actions required by this AD can be found in Boeing Alert Service Bulletin B787-81205-SB270055-00, Issue 002, dated November 25, 2024, which is ( printed page 12951) referred to in Boeing Alert Requirements Bulletin B787-81205-SB270055-00 RB, Issue 002, dated November 25, 2024.
Accomplishing the actions required by paragraph (l) of this AD terminates the requirements of paragraphs (g), (i), and (j) of this AD for that airplane. After all affected airplanes in an operator's fleet have complied with paragraph (l) of this AD, the AFM revision required by paragraph (i) of this AD may be removed and the maintenance or inspection program revision required by paragraph (j) of this AD may be removed.
Where the Compliance Time column of the tables in the “Compliance” paragraph of Boeing Alert Requirements Bulletin B787-81205-SB270055-00 RB, Issue 002, dated November 25, 2024, refers to the Issue 001 date of Requirements Bulletin B787-81205-SB270055-00 RB, this AD requires using the effective date of this AD.
This paragraph provides credit for the actions specified in paragraph (l) of this AD, if those actions were performed before the effective date of this AD using Boeing Alert Requirements Bulletin B787-81205-SB270055-00 RB, Issue 001, dated December 12, 2023.
(1) The Manager, AIR-520, Continued Operational Safety 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 responsible Flight Standards Office, as appropriate. If sending information directly to the manager of the Continued Operational Safety Branch, send it to the attention of the person identified in paragraph (q)(1) of this AD. Information may be emailed to: AMOC@faa.gov. Before using any approved AMOC, notify your appropriate principal inspector, or lacking a principal inspector, the manager of the responsible Flight Standards Office.
(2) An AMOC that provides an acceptable level of safety may be used for any repair, modification, or alteration required by this AD if it is approved by The Boeing Company Organization Designation Authorization (ODA) that has been authorized by the Manager, AIR-520, Continued Operational Safety Branch, FAA, to make those findings. To be approved, the repair method, modification deviation, or alteration deviation must meet the certification basis of the airplane, and the approval must specifically refer to this AD.
(3) AMOCs approved for AD 2019-20-07 are approved as AMOCs for the corresponding provisions of paragraphs (g), (i), and (j) of this AD.
(1) For more information about this AD, contact Emanuel Chaves Torres, Aviation Safety Engineer, FAA, 2200 South 216th St., Des Moines, WA 98198; phone: 562-627-5350; email: emanuel.chaves.torres@faa.gov.
(2) Material identified in this AD that is not incorporated by reference is available at the address specified in paragraph (r)(5) of this AD.
(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 this AD specifies otherwise.
(3) The following material was approved for IBR on [DATE 35 DAYS AFTER PUBLICATION OF THE FINAL RULE].
(i) Boeing Alert Requirements Bulletin B787-81205-SB270055-00 RB, Issue 002, dated November 25, 2024.
(ii) [Reserved]
(4) The following material was approved for IBR on October 11, 2019 (84 FR 54765, October 11, 2019).
(i) Boeing Alert Requirements Bulletin B787-81205-SB270051-00 RB, Issue 001, dated July 5, 2019.
(ii) [Reserved]
(5) For 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 myboeingfleet.com.
(6) 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.
(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.
Issued on March 12, 2026.
Lona C. Saccomando,
Acting Deputy Director, Integrated Certificate Management Division, Aircraft Certification Service.
4 comments have been received at Regulations.gov.
Agencies review all submissions and may choose to redact, or withhold, certain submissions (or portions thereof). Submitted comments may not be available to be read until the agency has approved them.