Airworthiness Directives; The Boeing Company Airplanes, 12682-12685 [2025-04440]

Agencies

• Federal Aviation Administration
• DEPARTMENT OF TRANSPORTATION

[Federal Register Volume 90, Number 52 (Wednesday, March 19, 2025)]
[Rules and Regulations]
[Pages 12682-12685]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2025-04440]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2023-2151; Project Identifier AD-2023-00984-T; 
Amendment 39-22990; AD 2025-06-02]
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 all 
The Boeing Company Model 777-200, -200LR, -300, -300ER, and 777F series 
airplanes. This AD was prompted by a report of a 5-inch crack on the 
upper wing skin at a certain wing station of the right wing. This AD 
requires repetitive inspections for cracking of the upper wing skin 
common to certain fasteners 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 23, 2025.
    The Director of the Federal Register approved the incorporation by 
reference of a certain publication listed in this AD as of April 23, 
2025.

ADDRESSES: 
    AD Docket: You may examine the AD docket at regulations.gov under 
Docket No. FAA-2023-2151; 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-2023-2151.

FOR FURTHER INFORMATION CONTACT: Luis Cortez-Muniz, Aviation Safety 
Engineer, FAA, 2200 South 216th St., Des Moines, WA 98198; phone: 206-
231-3958; 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 all The Boeing Company 
Model 777-200, -200LR, -300, -300ER, and 777F series airplanes. The 
NPRM published in the Federal Register on November 17, 2023 (88 FR 
80216). The NPRM was prompted by a report of a 5-inch crack on the 
upper wing skin at wing station (WSTA) 460 of the right wing. In the 
NPRM, the FAA proposed to require repetitive inspections for cracking 
of the upper wing skin common to certain fasteners and applicable on-
condition actions, including repair.
    The FAA issued a supplemental notice of proposed rulemaking (SNPRM) 
to amend 14 CFR part 39 by adding an AD that would apply to all The 
Boeing Company Model 777-200, -200LR, -300, -300ER, and 777F series 
airplanes. The SNPRM published in the Federal Register on September 20, 
2024 (89 FR 77049). The SNPRM was prompted by reports from Boeing of 
two events of cracking at the fastener 6 and 7 locations where the 
cracks initiated in the spanwise (inboard/outboard) direction. These 
cracks were detected only because of a repair accomplished on an 
adjacent fastener. The areas around the repaired fasteners were 
subsequently inspected with an open hole high frequency eddy current 
(HFEC) inspection, rather than with the ultrasonic (UT) inspection that 
was proposed in the NPRM. The SNPRM therefore proposed to require open 
hole HFEC inspections instead of UT inspections. The FAA is issuing 
this AD to address the possibility of an undetected upper wing skin 
crack.

[[Page 12683]]

Discussion of Final Airworthiness Directive

Comments

    The FAA received comments from five commenters, including Boeing 
and three individuals who supported the SNPRM without change, and 
American Airlines who supported the inspections specified in the SNPRM 
and also provided additional comments.
    The FAA received additional comments from five commenters, 
including All Nippon Airways, Air France, FedEx, American Airlines, and 
United Airlines (United). The following presents the comments received 
on the SNPRM and the FAA's response to each comment.

Request for Compliance Time Extension

    American Airlines and United requested a compliance time extension 
for previously inspected airplanes. American Airlines requested that 
airplanes on which Boeing Alert Requirements Bulletin 777-57A0125 RB, 
dated July 25, 2023, is accomplished by completing the UT inspections 
without the fastener 6 and 7 open hole HFEC inspections and had no 
crack findings be allowed to fly up to 4,700 flight cycles or 10,300 
flight hours from the time of the inspection before they have to be 
brought back to accomplish the inspections with the newly proposed open 
hole HFEC inspections. The commenters did not provide justification for 
the request.
    United requested an additional grace period to conduct the fastener 
6 and 7 open hole HFEC inspection on airplanes where the UT inspection 
was already conducted prior to the issuance of the final rule. United 
stated that this additional time is requested to allow for proper 
planning and execution of the open hole HFEC inspection; these 
inspections require a significant amount of time and effort to 
accomplish and will impact United's maintenance check scheduling. 
Additionally, United noted the materials required for the on-condition 
corrective action are currently out of stock and are subject to 
extended lead times from Boeing.
    The FAA disagrees with the request for an extended compliance time 
for airplanes on which UT inspections have been done as specified in 
the NPRM prior to the publication of the final rule. As the UT 
inspection would not adequately detect cracks common to the 6 and 7 
fasteners, a grace period extension or allowing credit for accomplish 
the UT inspection may not adequately maintain an acceptable level of 
safety due to factors such as airplane age, utilization, inspection 
history, etc. In addition, the FAA notes that the on-condition 
corrective action is to contact Boeing for repair instructions and do 
the repair. The parts needed to do the repair will vary depending on 
the inspection findings. If parts for a specific repair are not 
available, operators may request a compliance time extension through 
alternative methods of compliance (AMOC) in accordance with paragraph 
(i) of this AD provided sufficient supporting data is submitted to show 
an acceptable level of safety is maintained.

Request for Clarification of Inspection Compliance Time

    Air France requested that the FAA clarify the fastener inspection 
compliance time for airplanes that have already accomplished inspection 
instructions in accordance with Boeing Alert Requirements Bulletin 777-
57A0125 RB, dated July 25, 2023, prior to the emergence of the issue 
regarding open hole HFEC inspection of fasteners 6 and 7. Air France 
requested compliance time clarification since Air France had already 
inspected some group 4 airplanes with no finding after the UT 
inspection to comply with Boeing Alert Requirements Bulletin 777-
57A0125 RB, dated July 25, 2023. Air France stated that no open hole 
HFEC inspection was performed on fasteners 6 and 7 on these airplanes 
and they are scheduled to be reinspected within 4,700 flight cycles or 
10,300 flight hours, whichever occurs first, after the first 
inspection. For these affected airplanes, Air France would like the FAA 
to specify if the open hole HFEC inspection on fasteners 6 and 7 is to 
be performed within 12 months or 4,300 flight hours, whichever occurs 
first, from the effective date of the proposed AD or at the next repeat 
inspection per Boeing Alert Requirements Bulletin 777-57A0125 RB, dated 
July 25, 2023, instructions.
    The FAA agrees to clarify the inspection compliance time. For 
airplanes on which the inspections specified in Boeing Alert 
Requirements Bulletin 777-57A0125 RB, dated July 25, 2023, were 
accomplished, without the open hole HFEC inspection for fasteners 6 and 
7, accomplishing the open hole HFEC inspection for the subject 
fasteners is required within the inspection compliance times required 
by this AD, as required by paragraphs (g) and (h) of this AD, which 
includes a grace period of within 12 months or 4,300 flight hours, 
whichever occurs first, after the effective date of this AD. For any 
airplanes inspected in accordance with Boeing Alert Requirements 
Bulletin 777-57A0125 RB, dated July 25, 2023, without the open hole 
HFEC inspection of the subject fasteners prior to the issuance of this 
AD, the FAA may consider compliance time extensions through AMOCs in 
accordance with paragraph (i) of this AD, provided sufficient 
supporting data is submitted to show an acceptable level of safety is 
maintained.

Request Credit for Previous Actions

    American Airlines and United requested credit for previous actions 
for fasteners 6 and 7. American Airlines requested that previous 
accomplishment of open hole HFEC inspections at fastener 6 and 7 during 
repairs of cracks in the subject inspection area are considered 
compliant with the initial inspections on the subject wing side. United 
requested credit for conducting open hole HFEC inspections on fasteners 
6 and 7 on group 4 airplanes before the AD issue date. The commenters 
did not provide justification for this request.
    The FAA agrees that previous accomplishment of open hole HFEC 
inspections at the subject fasteners are considered compliant if done 
as specified in paragraphs (g) and (h) of this AD. Paragraph (f) of 
this AD states to accomplish the required actions within the compliance 
times specified, ``unless already done.'' Therefore, if operators have 
accomplished the initial inspections required for compliance with this 
AD before the effective date of this AD, they are in compliance with 
those requirements. The FAA has not revised this AD in this regard.

Request for FAA To Allow Open Hole HFEC Inspections in Lieu of UT 
Inspections

    All Nippon Airways requested that the FAA accept the procedure to 
perform open hole HFEC inspections in lieu of UT inspections for 
affected fasteners or release an AD that requires revised service 
information reflecting this content. The commenter states that Boeing 
Information Notice 777-57A0125 IN 01, dated July 19, 2024, instructs 
operators to perform open hole HFEC in lieu of UT inspection. The 
commenter also stated formal Boeing approval via FAA Form 8100-9 will 
be needed because the open hole HFEC inspection in lieu of UT 
inspection has not been considered acceptable by the FAA.
    The FAA disagrees with the request to release an AD that requires 
revised service information to accept the procedure to perform open 
hole HFEC inspections in lieu of UT inspections for affected fasteners 
because the FAA has already identified the open hole HFEC procedure as 
indicated in paragraphs

[[Page 12684]]

(h)(4) through (7) of this AD. Additional approval would not be 
required as the open hole HFEC procedure is already required by the FAA 
in this AD. The FAA has not changed this AD in this regard.

Request To Limit Inspection to Certain Airplanes

    FedEx requested that paragraph (h)(7) of the proposed AD be revised 
to limit it to Model 777F (Group 6) airplanes with more than 40,000 
total flight hours or 6,500 total flight cycles. FedEx stated that 
based on its inspection results, the inspection intervals in Boeing 
Alert Requirements Bulletin 777-57A0125 RB, dated July 25, 2023, and 
the added requirements in paragraph (h)(7) of the proposed AD are not 
in the public interest.
    FedEx noted that no cracks were found on airplanes with less than 
48,000 total flight hours and for airplanes with more than 40,000 total 
flight hours, there is a low rate of crack findings with small cracks 
being found. FedEx concluded that the mandate to perform open hole HFEC 
inspections would result in a requirement to perform at least three 
sets of invasive, open hole inspections before an airplane reached 
48,000 total flight hours when micro-cracking was first observed. FedEx 
also stated that the removal of interference fit fasteners will 
typically require subsequent installation of an oversize fasteners and 
multiple fastener replacements is expected to adversely affect the 
joint stiffness and fatigue life of the subject wing spar region.
    The FAA acknowledges that removal of interference fit fasteners may 
require oversizing the fastener hole but does not agree with delaying 
the inspections because the FAA considered crack reports across the 
entire 777 fleet of airplanes in determining the compliance times. The 
FAA received reports of crack findings earlier than 40,000 total flight 
hours or 6,500 total flight cycles. Therefore, the FAA has not changed 
this AD in this regard. The FAA will, however, consider AMOCs in 
accordance with the paragraph (i) of this AD for compliance time 
extensions provided substantiation data is submitted to show an 
acceptable level of safety is maintained with the alternate inspection 
intervals.

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, this 
AD is adopted as proposed in the SNPRM. 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 777-57A0125 RB, 
dated July 25, 2023. This material specifies procedures for repetitive 
inspections for cracking of the upper wing skin common to certain 
fasteners and applicable on-condition actions. On-condition actions 
include repair.
    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 323 airplanes of U.S. 
registry. The FAA estimates the following costs to comply with this AD:

                                                 Estimated Costs
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                                                                                                 Cost on U.S.
              Action                    Labor cost        Parts cost      Cost per product        operators
----------------------------------------------------------------------------------------------------------------
Inspections......................  40 work-hours x $85        * $1,480  $4,880 per           $1,576,240 per
                                    per hour = $3,400                    inspection cycle.    inspection cycle.
                                    per inspection
                                    cycle.
----------------------------------------------------------------------------------------------------------------
* An inspection kit is required.

    The FAA has received no definitive data on which to base the cost 
estimates for the on-condition repairs specified in this AD.
    The FAA has included all known costs in its cost estimate. 
According to the manufacturer, however, some or all of the costs of 
this 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

    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.

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(f), 40113, 44701.


Sec.  39.13  [Amended]

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


[[Page 12685]]


2025-06-02 The Boeing Company: Amendment 39-22990; Docket No. FAA-
2023-2151; Project Identifier AD-2023-00984-T.

(a) Effective Date

    This airworthiness directive (AD) is effective April 23, 2025.

(b) Affected ADs

    None.

(c) Applicability

    This AD applies to all The Boeing Company Model 777-200, -200LR, 
-300, -300ER, and 777F series airplanes, certificated in any 
category.

(d) Subject

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

(e) Unsafe Condition

    This AD was prompted by a report of a 5-inch crack on the upper 
wing skin at wing station (WSTA) 460 of the right wing. The FAA is 
issuing this AD to address the possibility of an undetected upper 
wing skin crack. The unsafe condition, if not addressed, could 
result in the inability of the primary structural element to sustain 
limit load and could adversely affect the structural integrity of 
the airplane, resulting in loss of control 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 777-57A0125 RB, dated July 25, 2023, do 
all applicable actions identified in, and in accordance with, the 
Accomplishment Instructions of Boeing Alert Requirements Bulletin 
777-57A0125 RB, dated July 25, 2023.
    Note 1 to paragraph (g): Guidance for accomplishing the actions 
required by this AD can be found in Boeing Alert Service Bulletin 
777-57A0125, dated July 25, 2023, which is referred to in Boeing 
Alert Requirements Bulletin 777-57A0125 RB, dated July 25, 2023.

(h) Exceptions to Service Information Specifications

    (1) Where Boeing Alert Requirements Bulletin 777-57A0125 RB, 
dated July 25, 2023, uses the phrase ``the original issue date of 
Requirements Bulletin 777-57A0125 RB,'' this AD requires using the 
effective date of this AD.
    (2) Where Boeing Alert Requirements Bulletin 777-57A0125 RB, 
dated July 25, 2023, specifies contacting Boeing for repair 
instructions: This AD requires doing the repair before further 
flight using a method approved in accordance with the procedures 
specified in paragraph (i) of this AD.
    (3) Where note (a) of the tables in the ``Compliance'' paragraph 
and Accomplishment Instructions of Boeing Alert Requirements 
Bulletin 777-57A0125 RB, dated July 25, 2023, specifies that a 
``repair for any crack found on the left wing is terminating action 
to the repeat inspection on the left wing only,'' or that a ``repair 
for any crack found on the right wing is terminating action to the 
repeat inspection on the right wing only,'' for this AD, performing 
a repair for any crack in accordance with the procedures specified 
in paragraph (i) of this AD terminates the repetitive inspections 
required by (g) of this AD at the repaired area only.
    (4) For Model 777-300 (Group 3) airplanes, where Boeing Alert 
Requirements Bulletin 777-57A0125 RB, dated July 25, 2023, specifies 
an ultrasonic (UT) inspection of the upper wing skin common to 
fasteners 11 and 12, this AD requires an open hole high frequency 
eddy current (HFEC) inspection of fasteners 11 and 12 in accordance 
with Figures 5 and 6 (for the left wing) or Figures 18 and 19 (for 
the right wing), as applicable.
    (5) For Model 777-300ER (Group 4) airplanes, where Boeing Alert 
Requirements Bulletin 777-57A0125 RB, dated July 25, 2023, requires 
a UT inspection of the upper wing skin common to fasteners 6 and 7, 
this AD requires this AD requires an open hole HFEC inspection of 
fasteners 6 and 7 in accordance with Figures 30 and 34 (for the left 
wing) or Figures 39 and 43 (for the right wing), as applicable.
    (6) For Model 777-200LR (Group 5) airplanes, where Boeing Alert 
Requirements Bulletin 777-57A0125 RB, dated July 25, 2023, requires 
a UT inspection of the upper wing skin common to fasteners 6 and 7, 
this AD requires an open hole HFEC inspection of fasteners 6 and 7 
in accordance with Figures 30 and 34 (for the left wing) or Figures 
39 and 43 (for the right wing), as applicable.
    (7) For Model 777F (Group 6) airplanes, where Boeing Alert 
Requirements Bulletin 777-57A0125 RB, dated July 25, 2023, requires 
a UT inspection of the upper wing skin common to fasteners 6 and 7, 
this AD requires an open hole HFEC inspection of fasteners 6 and 7 
in accordance with Figures 30 and 34 (for the left wing) or Figures 
39 and 43 (for the right wing), as applicable.

(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 certification office, 
send it to the attention of the person identified in paragraph 
(j)(1) of this AD. Information may be emailed to: [email protected].
    (2) Before using any approved AMOC, notify your appropriate 
principal inspector, or lacking a principal inspector, the manager 
of the responsible Flight Standards Office.
    (3) 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) Related Information

    (1) For more information about this AD, contact Luis Cortez-
Muniz, Aviation Safety Engineer, FAA, 2200 South 216th St., Des 
Moines, WA 98198; phone: 206-231-3958; 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 (IBR) of the service information listed 
in this paragraph under 5 U.S.C. 552(a) and 1 CFR part 51.
    (2) You must use this service information as applicable to do 
the actions required by this AD, unless the AD specifies otherwise.
    (i) Boeing Alert Requirements Bulletin 777-57A0125 RB, dated 
July 25, 2023.
    (ii) [Reserved]
    (3) For Boeing material, 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 13, 2025.
Peter A. White,
Deputy Director, Integrated Certificate Management Division, Aircraft 
Certification Service.
[FR Doc. 2025-04440 Filed 3-18-25; 8:45 am]
BILLING CODE 4910-13-P