[Federal Register Volume 91, Number 48 (Thursday, March 12, 2026)]
[Rules and Regulations]
[Pages 12059-12064]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2026-04829]



[[Page 12059]]

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2025-0618; Project Identifier AD-2024-00637-T; 
Amendment 39-23280; AD 2026-05-07]
RIN 2120-AA64


Airworthiness Directives; The Boeing Company Airplanes

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule.

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SUMMARY: The FAA is adopting a new airworthiness directive (AD) for 
certain The Boeing Company Model 767-200, -300, -300F, and -400ER 
series airplanes. This AD was prompted by discovery of a crack at one 
of the forward lower fastener holes following replacement of a cracked 
underwing longeron (UWL) fitting. This AD requires performing an open 
hole high frequency eddy current (HFEC) inspection for cracks of the 
fastener holes common to the UWL fitting, upper drag splice angle, and 
lower drag splice angle, and applicable on-condition actions. The FAA 
is issuing this AD to address the unsafe condition on these products.

DATES: This AD is effective April 16, 2026.
    The Director of the Federal Register approved the incorporation by 
reference of a certain publication listed in this AD as of April 16, 
2026.

ADDRESSES: AD Docket: You may examine the AD docket at regulations.gov 
under Docket No. FAA-2025-0618; 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.
    Material Incorporated by Reference:
     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.
     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-2025-0618.

FOR FURTHER INFORMATION CONTACT: Stefanie Roesli, Aviation Safety 
Engineer, FAA, 2200 South 216th St., Des Moines, WA 98198; phone: 206-
231-3964; email: [email protected].

SUPPLEMENTARY INFORMATION:

Background

    The FAA issued a notice of proposed rulemaking (NPRM) to amend 14 
CFR part 39 by adding an AD that would apply to certain The Boeing 
Company Model 767-200, -300, -300F, and -400ER series airplanes. The 
NPRM was published in the Federal Register on April 10, 2025 (90 FR 
15318). The NPRM was prompted by discovery of a crack at one of the 
forward lower fastener holes, outside of the inspection area of Boeing 
Alert Service Bulletin 767-57A0126, following replacement of a cracked 
UWL fitting. In the NPRM, the FAA proposed to require performing an 
HFEC inspection for cracks of the fastener holes common to the UWL 
fitting, upper drag splice angle, and lower drag splice angle and 
applicable on-condition actions. The FAA is issuing this AD to ensure 
that any crack in the forward lower fastener holes at the UWL fitting 
is found and repaired before reaching a critical length. Such cracking, 
if not addressed, could result in loss in the primary load path between 
the fuselage and the wing box, adversely affecting the structural 
integrity of the airplane.

Discussion of Final Airworthiness Directive

Comments

    The FAA received comments from Aviation Partners Boeing and ProTech 
Aero Services Limited who supported the NPRM without change.
    The FAA received additional comments from four commenters, 
including Boeing, Delta Air Lines (Delta), FedEx Express (FedEx), and 
United Airlines (United). The following presents the comments received 
on the NPRM and the FAA's response to each comment.

Request To Clarify What Prompted the Proposed AD

    Boeing requested that the FAA revise the first sentence of 
paragraph (e) of the proposed AD to state that this AD was prompted by 
discovery of a crack at one of the UWL fitting forward fastener holes, 
outside of the inspection area of Boeing Alert Service Bulletin 767-
57A0126, following replacement of a cracked UWL fitting. The commenter 
clarified that the crack was discovered on the UWL fitting outside of 
the inspection area, not outside of the UWL fitting.
    The FAA agrees and has revised paragraph (e) accordingly.

Request To Clarify the Inspection Compliance Time Based on UWL 
Replacement

    Boeing requested that the FAA add the following exception to 
paragraph (h) of the proposed AD: Where the Compliance Time column of 
the tables in the ``Compliance'' paragraph of Boeing Alert Requirements 
Bulletin 767-57A0148 RB, dated October 10, 2024, refers to ``after the 
replacement of the underwing longeron fitting,'' the compliance time 
includes fitting replacement in accordance with Boeing Alert Service 
Bulletin 767-57A0126, Revision 1, dated November 9, 2011; Revision 2, 
dated March 12, 2012; Revision 3, dated November 8, 2012; Revision 4, 
dated April 17, 2014; and Revision 5, dated April 7, 2016 (Revisions 1 
through 5 of Boeing Alert Service Bulletin 767-57A0126). The commenter 
stated this exception clarifies the compliance time for operators who 
have replaced fittings using Revisions 1 through 5 of Boeing Alert 
Service Bulletin 767-57A0126. The commenter also stated that the 
compliance time for the initial open hole HFEC inspection is based on 
an individual fitting's flight cycles or flight hours, not the 
airplane's accumulated flight cycles or flight hours, and that 
replacement of the fitting per Revisions 1 through 5 of Boeing Alert 
Service Bulletin 767-57A0126 resets the compliance time even though it 
is not explicitly stated.
    The FAA agrees that the compliance time for the initial open hole 
HFEC inspection in tables 3 and 4 of the Boeing Alert Requirements 
Bulletin 767-57A0148 RB, dated October 10, 2024, can be calculated from 
the replacement of the UWL fitting using either Boeing Alert 
Requirements Bulletin 767-57A0148 RB, dated October 10, 2024, or 
Revisions 1 through 5 of Boeing Alert Service Bulletin 767-57A0126. 
Accordingly, the FAA has added a new exception to paragraph (h)(2) of 
this AD to clarify that compliance time.

Request To Correct Paragraph Reference

    Boeing requested that the FAA revise paragraph (h)(2) of the 
proposed AD to refer to paragraph (i) instead of paragraph (g) of the 
proposed AD. The commenter stated paragraph (i) of the

[[Page 12060]]

proposed AD should be referenced for repairs that require alternative 
methods of compliance (AMOC) approval.
    The FAA agrees and has revised paragraph (h)(3) of this AD 
(corresponding to paragraph (h)(2) of the proposed AD) accordingly.

Request To Remove or Revise Requirement for Minimum Thickness of Cap 
Seals

    Boeing requested that the FAA remove paragraph (h)(3) and figure 1 
from the proposed AD. Boeing stated Boeing Alert Requirements Bulletin 
767-57A0148 RB, dated October 10, 2024, refers to section 28-11-00 of 
the 767 Aircraft Maintenance Manual (AMM) (i.e., 767 AMM 28-11-00) for 
the cap sealing procedure, and the AMM contains the same cap seal 
minimum thickness specified in figure 1 to paragraph (h)(3) of the 
proposed AD. Boeing asserted that deleting the proposed requirement 
would prevent duplication of data and potential questions from 
operators.
    Alternatively, Boeing requested the FAA revise paragraph (h)(3) of 
the proposed AD to clarify that the requirement applies to in-tank 
fastener cap sealing only and add a note to refer to 767 AMM 28-11-00 
as an acceptable cap sealing procedure for in-tank fasteners. Boeing 
stated this clarification would prevent potential questions from 
operators and eliminate conflicting cap sealing requirements for out-
of-tank fasteners.
    The FAA agrees that the cap sealing requirement of paragraph (h)(4) 
of this AD (corresponding to paragraph (h)(3) of the proposed AD) does 
not apply to fasteners outside the fuel tank. Accordingly, the FAA has 
revised paragraph (h)(4) of this AD to clarify the requirement applies 
only to fasteners, fastener heads, and fastener threads and collars 
inside the fuel tank.
    The FAA disagrees with Boeing's request to remove the exception or 
add a note to refer to 767 AMM 28-11-00 as an acceptable procedure for 
the cap sealing required for in-tank fasteners. Boeing Alert 
Requirements Bulletin 767-57A0148 RB, dated October 10, 2024, already 
refers to 767 AMM 28-11-00 as an acceptable procedure, so including 
such a note in this AD is unnecessary. Further, referencing material as 
an accepted procedure does not make the actions in the material 
mandatory. Therefore, the FAA has determined that the exception in 
paragraph (h)(4) is necessary to ensure the cap sealing procedures are 
enforceable.

Request To Require Other Service Information for Cap Sealing 
Requirement

    FedEx requested that the FAA remove figure 1 and revise paragraph 
(h)(3) of the proposed AD to require application of the cap seals to 
wing tank fasteners internally, in accordance with section 51-20-05 of 
the 767 Structural Repair Manual (SRM) (i.e., 767 SRM 51-20-05). FedEx 
stated the exception in paragraph (h)(3) of the proposed AD would 
result in multiple requirements for cap sealing of fasteners internal 
to the fuel tank, depending on the task being worked. FedEx also stated 
that the exception is overly general and should be specific only to cap 
seals internal to the fuel tank. FedEx noted fasteners that penetrate 
the 767 fuel tank are subject to Critical Design Configuration Control 
Limitations (CDCCLs) to ensure the lightning, fault current, and hot 
short protection requirements of Airworthiness Limitation (AWL) 28-AWL-
08 are met. FedEx also noted that AWL 28-AWL-08 specifies no additional 
FAA Oversight Office approval is required if the repair or alternation 
is accomplished using 767 SRM procedures.
    As stated previously, the FAA agrees that the cap sealing 
requirement does not apply to fasteners outside the fuel tank and has 
revised paragraph (h)(4) of this AD accordingly. However, the FAA 
disagrees with the commenter's request to require that the cap sealing 
for in-tank fasteners be done in accordance with 767 SRM 51-20-05 
because the SRM refers to 767 AMM 28-11-00 for sealing of fuel tank 
repairs. Referring to 767 AMM 28-11-00 does not make the actions in 
that material mandatory, and the FAA has determined that the 
requirements in paragraph (h)(4) of this AD must be accomplished. 
Further, the FAA disagrees that the exception will result in multiple 
requirements for cap sealing of fasteners internal to the fuel tank 
because the 767 AMM 28-11-00 contains the same procedures as the 
requirements of figure 1 to paragraph (h)(4) of this AD. The FAA has 
not changed the AD in this regard.

Request To Correct Action and Figure Reference

    United requested that the FAA add an exception to paragraph (h) of 
the proposed AD to correct the instructions and figure reference for 
Condition 3 (Action 2) in table 1, ``Left Side Underwing Longeron 
Fitting Forward Lower Fastener Holes Inspection'' (for Group 1, 
Configuration 1 and 3) in the Accomplishment Instructions of Boeing 
Alert Requirements Bulletin 767-57A0148 RB, dated October 10, 2024. The 
commenter stated that Condition 3 (Action 2) incorrectly specifies 
performing the HFEC at any hole(s) per figure 3, instead of figure 35. 
The commenter noted the correct instructions are specified in another 
condition for the right side underwing longeron fitting inspection. The 
commenter also stated that Boeing concurred with this change.
    The FAA agrees to correct the figure reference and instructions for 
Condition 3 (Action 2) as requested by the commenter. The FAA notes 
that the requested change to the instructions is consistent with the 
``Action'' column for Condition 3 (Action 2) of table 1, ``Left Side 
Underwing Longeron Fitting Forward Lower Fastener Holes Inspection,'' 
in the ``Compliance'' paragraph of Boeing Alert Requirements Bulletin 
767-57A0148 RB, dated October 10, 2024. Accordingly, the FAA has added 
a new exception in paragraph (h)(5) of this AD.

Request To Correct Task Name

    Delta requested that the FAA add an exception to paragraph (h) of 
the proposed AD to correct the task name to ``FITTING, UNDERWING 
LONGERON, RH'' in step 5 of figures 6, 8, and 10 of Boeing Alert 
Requirements Bulletin 767-57A0148 RB, dated October 10, 2024. Delta 
stated that those figures are for the right-hand UWL longeron, not the 
left-hand.
    The FAA agrees to correct the task name in figures 6, 8, and 10 of 
Boeing Alert Requirements Bulletin 767-57A0148 RB, dated October 10, 
2024, as requested by Delta. Accordingly, the FAA has added a new 
exception to paragraph (h)(6) of this AD.

Request To Clarify Procedures for Fastener Installation

    Boeing requested that the FAA add an exception to paragraph (h) of 
the proposed AD that requires fasteners installed per Boeing Alert 
Requirements Bulletin 767-57A0148 RB, dated October 10, 2024, figures 
15 through 22, 27, and 28, step 11 (quantity 8) and figures 23 through 
26, step 11 (quantity 7) be cap sealed per step 15. Boeing stated 
Boeing Alert Requirements Bulletin 767-57A0148 RB, dated October 10, 
2024, omitted the cap sealing requirements (step 15) for certain 
fasteners installed per step 11 of the referenced figures. 
Alternatively, Boeing requested that the FAA revise the proposed AD to 
mandate Revision 1 of the material, which it plans to issue as soon as 
possible to add the omitted cap sealing requirements.

[[Page 12061]]

    The FAA agrees that fasteners installed in accordance with step 11 
of the applicable figure in Boeing Alert Requirements Bulletin 767-
57A0148 RB, dated October 10, 2024, should be cap sealed in accordance 
with step 15. Further, fasteners installed in accordance with step 8 of 
the same figures should also be cap sealed in accordance with step 15. 
Sealing all of these fasteners is necessary to prevent possible 
ignition sources within the fuel tank. Accordingly, the FAA has added a 
new exception in paragraph (h)(7) of this AD. Under the provisions of 
paragraph (i) of this AD, Boeing may request an AMOC to allow use of 
Revision 1 to Boeing Alert Requirements Bulletin 767-57A0148 RB after 
it has been issued.
    In its comment, Boeing noted step 11 of figures 23 through 26 
involves 7 fasteners. However, the FAA notes that step 11 of those 
figures in Boeing Alert Requirements Bulletin 767-57A0148 RB, dated 
October 10, 2024, specifies a quantity of 8 fastener and that sheet 2 
of those figures only depicts 7 fastener locations. To address this 
inconsistency, the FAA has added a new exception to paragraph (h)(8) of 
this AD to require the installation of 7 fasteners.

Request To Correct Shim Part Number

    United requested that the FAA add an exception to paragraph (h) of 
the proposed AD to correct the part number (P/N) for Shim B in step 9 
of figures 23 through 26. The commenter stated that those figures 
specify removing P/N BACS40R021C037F and installing P/N 
BACS40R021C032F, but the correct instruction is to install the removed 
shim P/N BACS40R021C037F. The commenter also stated that Boeing 
concurred with this change.
    The FAA agrees to correct the part number in step 9 (installation) 
of figures 23 through 26 of Boeing Alert Requirements Bulletin 767-
57A0148 RB, dated October 10, 2024. Accordingly, the FAA has added a 
new exception in paragraph (h)(9) of this AD.

Request To Correct Step Reference

    United requested that the FAA add an exception to paragraph (h) of 
the proposed AD to correct step 2 of figure 34 (sheet 2 of 3) of Boeing 
Alert Requirements Bulletin 767-57A0148 RB, dated October 10, 2024. The 
commenter noted that although step 2 is mentioned on sheet 2 of figure 
34, there is no circle note 2 on sheet 1 of figure 34. The commenter 
stated that the fastener installation task in step 2 should be included 
in step 1, like the fastener installation for the left side UWL fitting 
in figure 33. The commenter also stated that Boeing concurred with this 
change.
    The FAA agrees that the fastener installation task should be 
included under step 1, not step 2. Accordingly, the FAA has added a new 
exception in paragraph (h)(10) of this AD.

Request To Revise Open Access Instruction

    Delta requested that the FAA add an exception to paragraph (h) of 
the proposed AD to revise step 1.a(3) in ``Part 1: Open Access'' of 
Boeing Alert Service Bulletin 767-57A0148, dated October 10, 2024. 
Delta stated that the instruction to make sure the airplane is at 
operational empty weight (OEW) with or without engines installed should 
instead specify to make sure the aircraft gross weight and center of 
gravity, with or without engines installed, are within approved limits 
for jacking the aircraft, and to refer to aircraft maintenance manual 
(AMM) 07-11-03 as an accepted procedure. Delta stated that Boeing Alert 
Service Bulletin 767-57A0148, dated October 10, 2024, does not define 
OEW, and each airline and manufacturer may have their own definition 
for OEW based on what they consider to be operational items.
    The FAA disagrees with Delta's request. The ``Part 1: Open Access'' 
steps are not tagged as required for compliance (RC) and therefore are 
not included as RC steps in Boeing Alert Requirements Bulletin 767-
57A0148 RB, dated October 10, 2024, which is required by this AD. 
Therefore, no change to this AD is necessary in this regard.

Request To Use Alternative Service Information

    Delta requested that the FAA add an exception to paragraph (h) of 
the proposed AD specifying the removal and installation procedures for 
the UWL replacement may be done using either Boeing Alert Requirements 
Bulletin 767-57A0148 RB, dated October 10, 2024, or Boeing Alert 
Service Bulletin 767-57A0126, Revision 5, dated April 7, 2016 (Revision 
5 of Boeing Alert Service Bulletin 767-57A0126). Delta stated Revision 
5 of Boeing Alert Service Bulletin 767-57A0126 is mandated by AD 2012-
15-12, Amendment 39-17141 (77 FR 46932, August 7, 2012) (AD 2012-15-
12). Delta also stated, if replacement of the UWL is required, the 
removal and installation procedures in both bulletins are required for 
compliance. Delta noted figures 5, 6, 9, and 10 of Boeing Alert 
Requirements Bulletin 767-57A0148 RB, dated October 10, 2024, contain 
removal instructions for the UWL fitting, inspections for an open hole 
HFEC inspection of the tension bolt hole, and a surface HFEC of the 
front spar lower chord, while figures 3, 4, 5, 6 in Revision 5 of 
Boeing Alert Service Bulletin 767-57A0126 contain instructions for the 
same actions. Delta also noted figures 15, 16, 23, and 24 of Boeing 
Alert Requirements Bulletin 767-57A0148 RB, dated October 10, 2024, 
contain installation instructions for the UWL fitting, while figures 7, 
8, 9, 10 contain instructions for the same action.
    The FAA disagrees with allowing use of alternative service 
information to accomplish this AD. AD 2012-15-12 does not affect 
accomplishment of this AD. If cracks are found while accomplishing an 
inspection required by this AD, the corrective actions must be 
accomplished according to this AD. The required actions of each AD are 
standalone because they address different unsafe conditions; one is for 
an inspection on the forward lower fastener holes where the underwing 
longeron fitting attaches to two drag splice angles, and the other is 
for an inspection of the underwing longeron fitting itself. The two ADs 
are only similar in the on-condition actions of the two inspections. 
The FAA has not changed this AD in this regard.

Request To Provide Fabrication Instructions

    Delta requested that the FAA add an exception to paragraph (h) of 
the proposed AD to state the fabrication instructions (materials, 
protective coatings, etc.) for fabricating shims. Delta noted step 1, 
More Data note (a) in figures 1 and 2 of Boeing Alert Service Bulletin 
767-57A0148, dated October 10, 2024, specifies if shims are installed 
in the joint, ensure they are kept in place during fastener removal, or 
are removed and retained for re-installation. Alternatively, the 
thickness can be measured to fabricate replacements. Due to this note, 
Delta asserted the fabrication instructions for shims should be clearly 
stated in the proposed AD.
    The FAA disagrees with Delta's request. Figures 1 and 2 of Boeing 
Alert Service Bulletin 767-57A0148, dated October 10, 2024, are not 
tagged as RC and therefore are not included as RC steps in Boeing Alert 
Requirements Bulletin 767-57A0148 RB, dated October 10, 2024, that is 
required by this AD. Therefore, no change to this AD is necessary in 
this regard.

[[Page 12062]]

Request To Clarify the Insurance Cut Note

    Delta requested that the FAA add an exception to paragraph (h) of 
the proposed AD to clarify step 1, More Data note (b) in figures 3 and 
4 of Boeing Alert Requirements Bulletin 767-57A0148 RB, dated October 
10, 2024, as a precaution. Delta stated that note should be a caution 
note because it specifies not to perform an insurance cut after the 
hole is confirmed crack-free by the HFEC inspection, but step 1 and 
More Data notes (a) and (b) do not specify to perform an insurance cut.
    The FAA disagrees with Delta's request. More Data note (a) 
specifies doing the HFEC inspection in accordance with the Boeing 767 
Non-Destructive Testing (NDT) Manual, which includes notes to perform 
insurance cuts after the inspection, to show the crack is fully 
removed. More Data note (b) is a directive to not perform those 
insurance cuts. Therefore, no change to this AD is necessary in this 
regard.

Conclusion

    The FAA reviewed the relevant data, considered any comments 
received, and determined that air safety requires adopting this AD as 
proposed. Accordingly, the FAA is issuing this AD to address the unsafe 
condition on these products. Except for minor editorial changes, and 
any other changes described previously, this AD is adopted as proposed 
in the NPRM. None of the changes will increase the economic burden on 
any operator.

Material Incorporated by Reference Under 1 CFR Part 51

    The FAA reviewed Boeing Alert Requirements Bulletin 767-57A0148 RB, 
dated October 10, 2024. This material specifies procedures for 
performing an open hole HFEC inspection for cracks of the fastener 
holes common to the UWL fitting, upper drag splice angle, and lower 
drag splice angle, and applicable on-condition actions. On-condition 
actions include crack repair (e.g., hole oversize repair), an open hole 
HFEC inspection of the fitting and angles for any crack at hole 
oversize repair locations, an open hole HFEC inspection of the entire 
fastener stack-up common to the tension bolt hole and a surface HFEC 
inspection of the front spar lower chord for any crack, replacement of 
the underwing longeron fitting with new underwing longeron fitting, 
underwing longeron fitting hole repair, tension bolt fastener stack-up 
repair, front spar lower chord repair, and subsequent repetitive open 
hole HFEC inspections for cracks of the fastener holes common to the 
UWL fitting, upper drag splice angle, and lower drag splice angle.
    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.

Costs of Compliance

    The FAA estimates that this AD affects 600 airplanes of U.S. 
registry. The FAA estimates the following costs to comply with this AD:

                                                 Estimated Costs
----------------------------------------------------------------------------------------------------------------
                                                                                     Cost per      Cost on U.S.
                 Action                          Labor cost           Parts cost      product        operators
----------------------------------------------------------------------------------------------------------------
HFEC inspection of fastener holes......  170 work-hours x $85 per             $0         $14,450      $8,670,000
                                          hour = $14,450.
----------------------------------------------------------------------------------------------------------------

    The FAA estimates the following costs to do any necessary on-
condition actions that would be required based on the results of the 
inspection. The agency has no way of determining the number of aircraft 
that might need these repairs:

                                              On-Condition Costs *
----------------------------------------------------------------------------------------------------------------
                Action                           Labor cost            Parts cost         Cost per product
----------------------------------------------------------------------------------------------------------------
Replacement..........................  19 work-hours x $85 per hour       $15,270  $16,885.
                                        = $1,615.
Inspections of the fitting and         Up to 6 work-hours x $85 = Up           $0  Up to $510.
 angles, the entire fastener stack-up   to $510.
 common to the tension bolt hole, and
 the front spar lower chord for any
 crack.
Repetitive HFEC inspection of          170 work-hours x $85 per hour           $0  $14,450.
 fastener holes.                        = $14,450.
----------------------------------------------------------------------------------------------------------------
* The FAA has received no definitive data on which to base the cost estimates for time and work for the repairs
  specified in this AD, as the work necessary is variable.

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

    This AD will not have federalism implications under Executive Order 
13132. This AD will 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 that this AD:
    (1) Is not a ``significant regulatory action'' under Executive 
Order 12866,
    (2) Will not affect intrastate aviation in Alaska, and
    (3) Will not have a significant economic impact, positive or 
negative, on a substantial number of small entities under the criteria 
of the Regulatory Flexibility Act.

[[Page 12063]]

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Incorporation by 
reference, Safety.

The Amendment

    Accordingly, under the authority delegated to me by the 
Administrator, the FAA amends 14 CFR part 39 as follows:

PART 39--AIRWORTHINESS DIRECTIVES

0
1. The authority citation for part 39 continues to read as follows:

    Authority: 49 U.S.C. 106(g), 40113, 44701.


Sec.  39.13   [Amended]

0
2. The FAA amends Sec.  39.13 by adding the following new airworthiness 
directive:

2026-05-07 The Boeing Company: Amendment 39-23280; Docket No. FAA-
2025-0618; Project Identifier AD-2024-00637-T.

(a) Effective Date

    This airworthiness directive (AD) is effective April 16, 2026.

(b) Affected ADs

    None.

(c) Applicability

    This AD applies to The Boeing Company Model 767-200, -300, -
300F, and -400ER series airplanes, certificated in any category, as 
identified in Boeing Alert Requirements Bulletin 767-57A0148 RB, 
dated October 10, 2024.

(d) Subject

    Air Transport Association (ATA) of America Code 57, Wings.

(e) Unsafe Condition

    This AD was prompted by discovery of a crack at one of the 
underwing longeron (UWL) fitting forward fastener holes, outside of 
the inspection area of Boeing Alert Service Bulletin 767-57A0126, 
following replacement of a cracked UWL fitting. The FAA is issuing 
this AD to ensure that any crack in the forward lower fastener holes 
at the UWL fitting is found and repaired before reaching a critical 
length. Such cracking, if not addressed, could result in loss in the 
primary load path between the fuselage and the wing box, adversely 
affecting the structural integrity of the airplane.

(f) Compliance

    Comply with this AD within the compliance times specified, 
unless already done.

(g) Required Actions

    Except as specified by paragraph (h) of this AD: At the 
applicable times specified in the ``Compliance'' paragraph of Boeing 
Alert Requirements Bulletin 767-57A0148 RB, dated October 10, 2024, 
do all applicable actions identified in, and in accordance with, the 
Accomplishment Instructions of Boeing Alert Requirements Bulletin 
767-57A0148 RB, dated October 10, 2024.
    Note 1 to paragraph (g): Guidance for accomplishing the actions 
required by this AD can be found in Boeing Alert Service Bulletin 
767-57A0148, dated October 10, 2024, which is referred to in Boeing 
Alert Requirements Bulletin 767-57A0148 RB, dated October 10, 2024.

(h) Exceptions to Requirements Bulletin Specifications

    (1) Where the Compliance Time column of the tables in the 
``Compliance'' paragraph of Boeing Alert Requirements Bulletin 767-
57A0148 RB, dated October 10, 2024, refers to the original issue 
date of Requirements Bulletin 767-57A0148 RB, this AD requires using 
the effective date of this AD.
    (2) Where the Compliance Time column of tables 3 and 4 in the 
``Compliance'' paragraph of Boeing Alert Requirements Bulletin 767-
57A0148 RB, dated October 10, 2024, specifies a compliance time of 
within 22,000 flight cycles or 80,000 flight hours after the 
replacement of the underwing longeron fitting, whichever occurs 
first, this AD requires that the compliance time be calculated from 
when replacement of the underwing longeron fitting was done using 
Boeing Alert Requirements Bulletin 767-57A0148 RB, dated October 10, 
2024; or Boeing Alert Service Bulletin 767-57A0126, Revision 1, 
dated November 9, 2011; Revision 2, dated March 12, 2012; Revision 
3, dated November 8, 2012; Revision 4, dated April 17, 2014; or 
Revision 5, dated April 7, 2016.
    (3) Where Boeing Alert Requirements Bulletin 767-57A0148 RB, 
dated October 10, 2024, specifies contacting Boeing for repair 
instructions, this AD requires doing the repair using a method 
approved in accordance with the procedures specified in paragraph 
(i) of this AD.
    (4) During application of any cap seal to a fastener, fastener 
head, and fastener threads and collars inside the tank, as required 
by this AD, the cap seal must be applied with a thickness equal to 
or greater than the dimensions specified in figure 1 to paragraph 
(h)(4) of this AD.

Figure 1 to Paragraph (h)(4)--Cap Seal Minimum Thickness (All 
Dimensions in Inches)

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    (5) Where Condition 3 (Action 2) of table 1 of the ``Work 
Instructions'' paragraph of Boeing Alert Requirements Bulletin 767-
57A0148 RB, dated October 10, 2024, specifies to repeat the open 
hole high frequency eddy current (HFEC) inspection at any hole(s) 
using ``figure 3'' as the method of compliance, this AD requires, at 
oversize hole repair location(s), doing an open hole HFEC inspection 
of the fitting and the angles for any crack using ``figure 35'' as 
the method of compliance.
    (6) Where the ``Action'' column of step 5 of figures 6, 8, and 
10 of Boeing Alert Requirements Bulletin 767-57A0148 RB, dated 
October 10, 2024, specifies ``FITTING, UNDERWING LONGERON, LH'', 
this AD requires replacing that text with ``FITTING, UNDERWING 
LONGERON, RH''.
    (7) Where step 15 of figures 15 through 28 of Boeing Alert 
Requirements Bulletin 767-57A0148 RB, dated October 10, 2024, 
specifies cap sealing fasteners (i.e., applying cap seal to wing 
tank fasteners internally with BMS 5-45), this AD requires cap 
sealing all fasteners installed in accordance with steps 8 and 11 of 
the applicable figure in Boeing Alert Requirements Bulletin 767-
57A0148 RB, dated October 10, 2024.
    (8) Where step 11 of figures 23 through 26 of Boeing Alert 
Requirements Bulletin 767-57A0148 RB, dated October 10, 2024, 
specifies installing a quantity of 8 fasteners, this AD requires 
installing 7 fasteners.
    (9) Where the ``Identification'' column of step 9 of figures 23 
through 26 of Boeing Alert Requirements Bulletin 767-57A0148 RB, 
dated October 10, 2024, specifies to install BACS40R021C032F, this 
AD requires installing BACS40R021C037F.
    (10) Where the ``Step'' column of figure 34 of Boeing Alert 
Requirements Bulletin 767-57A0148 RB, dated October 10, 2024, refers 
to step 2, this AD requires reidentifying step 2 as an additional 
step 1 task.

(i) Alternative Methods of Compliance (AMOCs)

    (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 (j)(1) of this AD. Information may be emailed to: 
[email protected]. 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.

(j) Additional Information

    (1) For more information about this AD, contact Stefanie Roesli, 
Aviation Safety Engineer, FAA, 2200 South 216th St., Des Moines, WA 
98198; phone: 206-231-3964; email: [email protected].
    (2) Material identified in this AD that is not incorporated by 
reference is available at the address specified in paragraph (k)(3) 
this AD.

(k) Material Incorporated by Reference

    (1) The Director of the Federal Register approved the 
incorporation by reference 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 the AD specifies otherwise.
    (i) Boeing Alert Requirements Bulletin 767-57A0148 RB, dated 
October 10, 2024.
    (ii) [Reserved]
    (3) 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.
    (4) 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.
    (5) 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 [email protected].

    Issued on March 4, 2026.
Lona C. Saccomando,
Acting Deputy Director, Integrated Certificate Management Division, 
Aircraft Certification Service.
[FR Doc. 2026-04829 Filed 3-11-26; 8:45 am]
BILLING CODE 4910-13-P