[Federal Register Volume 89, Number 54 (Tuesday, March 19, 2024)]
[Rules and Regulations]
[Pages 19501-19505]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2024-05497]


=======================================================================
-----------------------------------------------------------------------

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2022-0598; Project Identifier AD-2021-01322-T; 
Amendment 39-22688; AD 2024-04-09]
RIN 2120-AA64


Airworthiness Directives; The Boeing Company Airplanes

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule.

-----------------------------------------------------------------------

SUMMARY: The FAA is adopting a new airworthiness directive (AD) for 
certain The Boeing Company Model 777-200, 777-200LR, 777-300, 777-
300ER, and 777F series airplanes. This AD was prompted by reports of 
wing anti-ice (WAI) valve failure that can result in undetected 
structural damage to leading edge (LE) slat assemblies, and separately 
a failure of the autothrottle (A/T) to disconnect after the pilot 
manually advanced the throttle levers, which caused a low-speed 
condition during a go-around. This AD was also prompted by a 
determination that insufficient low-speed protection exists in the 777 
fleet and a determination that the flightcrew may not recognize and 
properly respond to a multi-channel unreliable airspeed event. This AD 
requires installing certain new software and doing a software 
configuration check. The FAA is issuing this AD to address the unsafe 
condition on these products.

DATES: This AD is effective April 23, 2024.
    The Director of the Federal Register approved the incorporation by 
reference of a certain publication listed in this AD as of April 23, 
2024.

ADDRESSES: 
    AD Docket: You may examine the AD docket at regulations.gov under 
Docket No. FAA-2022-0598; 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 service information identified in this final rule, 
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 service information 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-2022-0598.

FOR FURTHER INFORMATION CONTACT: Doug Tsuji, Aviation Safety Engineer, 
FAA, 2200 South 216th St., Des Moines, WA 98198; phone: 206-231-3548; 
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 777-200, 777-200LR, 777-300, 777-300ER, and 777F series 
airplanes. The NPRM published in the Federal Register on June 22, 2022 
(87 FR 37249). The NPRM was prompted by reports of WAI valve failure 
that can result in undetected structural damage to LE slat assemblies, 
and separately a failure of the A/T to disconnect after the pilot 
manually advanced the throttle levers, which caused a low-speed 
condition

[[Page 19502]]

during a go-around. The NPRM was also prompted by a determination that 
insufficient low-speed protection exists in the 777 fleet and a 
determination that the flightcrew may not recognize and properly 
respond to a multi-channel unreliable airspeed event. In the NPRM, the 
FAA proposed to require installing certain new software and doing a 
software configuration check. The FAA is issuing this AD to prevent 
undetected failure of the WAI system and consequent high temperature 
bleed air flowing into the LE slat assemblies, which could result in 
reduced structural integrity of the slat and prevent continued safe 
flight and landing of the airplane. The FAA is also issuing this AD to 
prevent failure of the A/T to disconnect after manually advancing the 
throttle levers, or insufficient low energy protection, which could 
result in controlled flight into terrain, or a multi-channel unreliable 
airspeed event could result in loss of control of the airplane.

Discussion of Final Airworthiness Directive

Comments

    The FAA received comments from the Air Line Pilots Association, 
International (ALPA) and an individual who supported the NPRM without 
change. Air Peace Limited (Air Peace) supported the NPRM, and had 
additional comments detailed below.
    The FAA received additional comments from four commenters, 
including Boeing, American Airlines, United Airlines (United), and Alis 
Cargo. The following presents the comments received on the NPRM and the 
FAA's response to each comment.

Request To Remove Certain Information From What Prompted the Proposed 
AD

    Boeing requested that the proposed AD be revised to remove all 
wording stating that the proposed AD ``was also prompted by a 
determination that insufficient low speed protection exists in the 777 
fleet and a determination that the flight crew may not recognize and 
properly respond to a multi-channel unreliable airspeed event.'' Boeing 
stated that the change that the AIMS Version 17C resolves is unrelated 
to unreliable airspeed indication, and that the Fault Tolerant air data 
inertial reference system (ADIRS) provides reliable airspeed data.
    The FAA agrees to clarify. The changes associated with AIMS-2 
Version 17C are not directly related to the issue of unreliable 
airspeed indication, and are intended to address the WAI issue and the 
A/T issue. However, the FAA disagrees with removing reference to the 
insufficient low-speed protection and unreliable airspeed because some 
of the changes associated with AIMS-2 Version 17C were to fix an unsafe 
condition (A/T issue) introduced by the previous AIMS-2 update (Version 
17B). The FAA acknowledges previous versions of AIMS software addressed 
unreliable airspeed (Version 17.1) and insufficient low airspeed 
protection (Version 17B) and that Version 17C has had these updates 
previously incorporated. However, neither of these earlier software 
updates were mandated by AD action. Therefore, this AD is addressing 
unreliable airspeed and insufficient low airspeed protection through 
requiring the software update that addresses all of the changes related 
to the identified unsafe condition. The FAA has not changed this AD 
regarding this issue.

Request To Move Certain Information

    Boeing requested that two sentences related to a requirement to 
install earlier BP versions of AIMS-2 BP software prior to installing 
AIMS-2 BP Version 17C software be moved from the Background to the 
Related Service Information Under 1 CFR part 51 section of the NPRM.
    The FAA acknowledges the commenter's request. However, the 
information in those sentences does not directly relate to the actions 
specified in the service information specified in the Related Service 
Information Under 1 CFR part 51 section of this final rule. Therefore, 
the FAA has determined that moving the information is not appropriate. 
Additionally, that portion of the Background section does not get 
carried over to the final rule. The FAA has not changed this AD 
regarding this issue.

Request To Revise Sentence Related to Earlier Software Update

    Boeing requested that the FAA revise a sentence in the Background 
section of the NPRM to specify that ``AIMS-2 BP V17B'' rather than 
``One earlier software update'' was prompted by an accident at San 
Francisco International Airport. Boeing stated that this would clarify 
that AIMS Version 17B is for the AIMS-2 platform.
    The FAA disagrees with the commenter's request. Within the context 
of the Background section of the NPRM, the FAA clearly identified 
``AIMS-2 BP Version 17B'' and that it was developed as a result of the 
accident investigation. Additionally, that portion of the Background 
section does not get carried over to the final rule. The FAA has not 
changed this AD regarding this issue.

Request To Correct Typographical Errors and Add Service Information 
Reference

    Boeing requested that the FAA correct several typographical errors 
in the Costs of Compliance section of the NPRM. Boeing noted that 
``AIMS 2'' should be ``AIMS-2;'' ``SB 777-21-0322'' should be ``SB 777-
31-0332;'' and that the action to install AIMS-2 BP Version 17C should 
specify bulletin ``777-31A0342.''
    The FAA agrees to correct these typographical errors and add the 
reference to the service information. The FAA has revised the Costs of 
Compliance section of this final rule accordingly.

Request To Revise Explanation of AIMS-2 BP Version 17C Software

    Boeing requested that the FAA revise the third paragraph of the 
Background portion of the NPRM to clarify why Boeing developed AIMS-2 
BP Version 17C software. Boeing provided suggested wording.
    The FAA agrees that Boeing's suggested wording would provide a more 
detailed description of why AIMS-2 BP Version 17C software was 
developed. However, that wording is not necessary to explain the 
requirements of and reasons for this AD. Additionally, that section of 
the Background portion does not get carried over to the final rule. 
Therefore, no change to this AD is necessary regarding this issue.

Request To Extend Compliance Time

    Air Peace Limited and United requested that, for operators that 
will require an upgrade of AIMS-1 to AIMS-2, the compliance time be 
extended to 48 months. Air Peace noted that the upgrade has a high cost 
and that there is a lead time for acquiring parts.
    The FAA disagrees with the commenters' request. In developing an 
appropriate compliance time for this action, the FAA considered the 
recommendations of the manufacturer, the urgency associated with the 
subject unsafe condition, and the availability of required parts. In 
consideration of these items, the FAA has determined that a 36 month 
compliance time will ensure an acceptable level of safety. However, 
under the provisions of paragraph (i) of this AD, the FAA will consider 
requests for approval of an extension of the compliance time if 
sufficient data are submitted to substantiate that the new compliance 
time would provide an acceptable level of safety. The FAA has not 
changed this AD in this regard.

[[Page 19503]]

Request To Allow Later-Approved Software

    American Airlines requested that paragraph (g) of the proposed AD 
be revised to specify that later-approved versions of the Block Point 
(BP) software are allowed for compliance. The commenter noted that this 
would minimize the need for alternative methods of compliance (AMOCs).
    The FAA agrees to clarify. Boeing Alert Requirements Bulletin 777-
31A0342 RB, dated July 19, 2021, which is incorporated by reference, 
already allows the installation of the specified software ``or later 
approved software part numbers'' and specifies in the General 
Information paragraph what constitutes ``later approved'' software. 
Therefore, no change to this AD is necessary.

Request To Remove Certain Airplanes From the Applicability

    Alis Cargo noted that its fleet has a current configuration of 
AIMS-1 BP Version 16, so is part of Group 5 as specified in Boeing 
Alert Requirements Bulletin 777-31A0342 RB, dated July 19, 2021. Alis 
Cargo added that no concurrent requirements are specified for Group 5 
airplanes in Boeing Alert Requirements Bulletin 777-31A0342 RB, dated 
July 19, 2021, making it unclear that a large and costly hardware 
upgrade from AIMS-1 to AIMS-2 is required. The commenter noted that the 
manufacturer said AIMS-1 hardware is limited and obsolete, so no 
dedicated software release is available for AIMS-1. The commenter 
stated that no known safety issues are related to AIMS-1 hardware, so 
operators should not be forced to upgrade the hardware to fix a 
software issue.
    The FAA infers that the commenter is requesting to remove airplanes 
equipped with AIMS-1 hardware from the applicability of this AD. The 
FAA acknowledges the high cost of converting from AIMS-1 to AIMS-2 
hardware and has updated the footnote in the Costs of Compliance 
section to estimate the parts cost for this action. The FAA has 
determined this action is necessary to address the unsafe condition. 
The unsafe condition is not AIMS-1 or AIMS-2 dependent, but rather is 
connected to the related BP software. Changes to the existing AIMS-1 
software (i.e., a more complex software code requiring more memory and 
computing capability) would exceed the capabilities of AIMS-1 hardware. 
Since the software running on AIMS-1 hardware is unsafe and cannot be 
upgraded on the AIMS-1 platform, affected airplanes must be converted 
to AIMS-2 hardware so that new software that addresses the unsafe 
conditions can be installed. The FAA has not changed this AD in this 
regard.

Request To Allow Using Certain Service Information

    United requested that the proposed AD be revised to include certain 
AIMS retrofit service bulletins, which include steps for replacing 
AIMS-1 with AIMS-2. United noted that Boeing provided several 
bulletins, which United used to accomplish the retrofit on a portion of 
its fleet that was equipped with AIMS-1. United concluded that 
specifying the service information would reduce the number of AMOC 
submittals.
    The FAA acknowledges the commenter's concerns. However, listing 
additional service information is not practical in this case because 
the bulletins that United mentioned may not be the only bulletins used 
to upgrade to AIMS-2, and some may be specific to a certain operator or 
certain airplane configuration. However, the FAA concurs that, if an 
airplane was upgraded to AIMS-2 prior to the effective date of this AD, 
obtaining an AMOC for the upgrade is no longer necessary. In addition, 
the FAA has determined that clarification of the definition of Group 5 
airplanes is necessary, since an airplane that was upgraded to AIMS-2 
after the service information was released might no longer fit into the 
group definitions in the service information. For an airplane on which 
AIMS-1 was upgraded to AIMS-2 prior to the effective date of this AD, 
obtaining an AMOC is not required. However, installing the AIMS-2 BP 
Version 17C software part numbers and doing a software configuration 
check are still required, along with any applicable concurrent actions. 
The FAA has added paragraph (h)(6) of this AD to clarify the group 
definition and requirements for airplanes that were upgraded to AIMS-2.

Request To Revise Costs of Compliance

    United requested that the Costs of Compliance section of the 
proposed AD be revised to account for higher hardware costs and more 
work-hours. United stated that Boeing Alert Requirements Bulletin 777-
31A0342 RB, dated July 19, 2021, implements ATN [Aeronautical 
Telecommunications Network] Controller Pilot Data Link Communications 
(CPDLC) for AIMS-2 airplanes. United added that AIMS-1 configured 
airplanes do not use the VDLMD2 radios required for CPDLC software that 
is part of the required BP17C software, so those airplanes also require 
a retrofit of VHF radios and OPC software, as well as replacement of 
the Tuning panel. The commenter also noted that the hardware cost for 
the AIMS retrofit is higher than that estimated in the proposed AD and 
provided suggested revised costs for installing AIMS-2 and BP17B/C.
    The FAA acknowledges the commenter's concerns and that upgrading 
from AIMS-1 to AIMS-2 may require additional modifications not 
accounted for in this AD. However, this AD does not require using 
specific service information to upgrade from AIMS-1 to AIMS-2, but 
instead requires obtaining an AMOC, as specified in paragraph (h)(2) of 
this AD. The FAA has no way of knowing the specific configuration of 
each airplane equipped with AIMS-1 and cannot account for all possible 
incidental costs that may be required in upgrading a particular 
airplane to AIMS-2. The cost information specified in this AD describes 
only the direct costs of the specific actions required by this AD. 
Based on the best data available, the manufacturer provided the 
estimated number of work hours and parts costs necessary to do the 
required actions. This number represents the time necessary to perform 
only the actions actually required by this AD. The FAA recognizes that, 
in doing the actions required by an AD, operators might incur 
incidental costs in addition to the direct costs. The cost analysis in 
AD rulemaking actions, however, typically does not include incidental 
costs such as the time necessitated by other administrative actions or 
incorporating other associated technologies. Those incidental costs 
might vary significantly among operators. Therefore, the FAA has not 
changed this AD regarding this issue.

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.

Related Service Information Under 1 CFR Part 51

    The FAA reviewed Boeing Alert Requirements Bulletin 777-31A0342 RB, 
dated July 19, 2021. This service information specifies procedures for 
installing new AIMS-2 BP Version 17C

[[Page 19504]]

software, and doing a software configuration check. For Groups 1, 2, 
and 3: this service information also specifies concurrent actions 
(installation of AIMS-2 BP Version 17B software; installation of AIMS-2 
and PlaneNet-2 systems; or installation of AIMS-2 and software; 
depending on configuration). This service information is reasonably 
available because the interested parties have access to it through 
their normal course of business or by the means identified in 
ADDRESSES.

Costs of Compliance

    The FAA estimates that this AD affects 353 airplanes of U.S. 
registry. The FAA estimates the following costs to comply with this AD:

                                                                    Estimated Costs *
--------------------------------------------------------------------------------------------------------------------------------------------------------
              Action                      Labor cost                 Parts cost                   Cost per product             Cost on U.S. operators
--------------------------------------------------------------------------------------------------------------------------------------------------------
Install AIMS-2 BP Version 17C and   3 work-hours x $85     Up to $13,140.................  Up to $13,395.................  Up to $4,728,435.
 do software check (777-31A0342      per hour = $255.
 RB).
Install AIMS-2 BP Version 17B       3 work-hours x $85     Up to $13,140.................  Up to $13,395.................  Up to $4,728,435.
 (SB777[dash]31[dash]0294).          per hour = $255.
Install AIMS-2 and PlaneNet-2 (SB   Up to 101 work-hours   Up to $13,140.................  Up to $21,725.................  Up to $7,668,925.
 777[dash]31[dash]0331).             x $85 per hour = Up
                                     to $8,585.
Install AIMS-2 and software (SB     Up to 106 works-hours  Up to $13,140.................  Up to $22,150.................  Up to $7,818,950.
 777-31-0322).                       x $85 per hour = Up
                                     to $9,010.
--------------------------------------------------------------------------------------------------------------------------------------------------------
* This software parts cost is estimated to be the same for the concurrent actions as for the primary actions. The FAA does not have any definitive data
  on which to base the additional parts cost associated with installing AIMS-2, but estimates the cost could be up to $762,500, depending on airplane
  configuration. Additionally, the FAA estimates that 100 airplanes of U.S. registry may require installing AIMS-2.

    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(g), 40113, 44701.


Sec.  39.13  [Amended]

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

2024-04-09 The Boeing Company: Amendment 39-22688; Docket No. FAA-
2022-0598; Project Identifier AD-2021-01322-T.

(a) Effective Date

    This airworthiness directive (AD) is effective April 23, 2024.

(b) Affected ADs

    None.

(c) Applicability

    This AD applies to The Boeing Company Model 777-200, 777-200LR, 
777-300, 777-300ER, and 777F series airplanes, certificated in any 
category, as identified in Boeing Alert Requirements Bulletin 777-
31A0342 RB, dated July 19, 2021.

(d) Subject

    Air Transport Association (ATA) of America Code 31, Instruments.

(e) Unsafe Condition

    This AD was prompted by reports of wing anti-ice (WAI) valve 
failure that can result in undetected structural damage to leading 
edge (LE) slat assemblies, and separately a failure of the 
autothrottle (A/T) to disconnect after the pilot manually advanced 
the throttle levers disconnect after the pilot manually advanced the 
throttle levers, which caused a low-speed condition during a go-
around. This AD was also prompted by a determination that 
insufficient low-speed protection exists in the 777 fleet and a 
determination that the flightcrew may not recognize and properly 
respond to a multi-channel unreliable airspeed event. The FAA is 
issuing this AD to prevent undetected failure of the WAI system and 
consequent high temperature bleed air flowing into the LE slat 
assemblies, which could result in reduced structural integrity of 
the slat and prevent continued safe flight and landing of the 
airplane. The FAA is also issuing this AD to prevent failure of the 
A/T to disconnect after manually advancing the throttle levers, or 
insufficient low energy protection, which could result in controlled 
flight into terrain, or a multi-channel unreliable airspeed event 
could result in loss of control of the airplane.

(f) Compliance

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

[[Page 19505]]

(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 777-31A0342 RB, dated July 19, 2021, do 
all applicable actions identified in, and in accordance with, the 
Accomplishment Instructions of Boeing Alert Requirements Bulletin 
777-31A0342 RB, dated July 19, 2021.
    Note 1 to paragraph (g): Guidance for accomplishing the actions 
required by this AD can be found in Boeing Alert Service Bulletin 
777-31A0342, dated July 19, 2021, which is referred to in Boeing 
Alert Requirements Bulletin 777-31A0342 RB, dated July 19, 2021.

(h) Exceptions to Service Information Specifications

    (1) Where the Compliance Time columns of the tables in the 
``Compliance'' paragraph of Boeing Alert Requirements Bulletin 777-
31A0342 RB, dated July 19, 2021, use the phrase ``the original issue 
date of Requirements Bulletin 777-31A0342 RB,'' this AD requires 
using the effective date of this AD.
    (2) Where Boeing Alert Requirements Bulletin 777-31A0342 RB, 
dated July 19, 2021, specifies contacting Boeing for instructions 
for upgrading certain software: This AD requires doing the upgrade 
using a method approved in accordance with the procedures specified 
in paragraph (i) of this AD.
    (3) Where the description in the Effectivity section of Boeing 
Alert Requirements Bulletin 777-31A0342 RB, dated July 19, 2021, 
defines Group 1 airplanes as ``Airplanes with Airplane Information 
Management System (AIMS)-2 with service bulletin 777-31-0294 
incorporated,'' this AD requires using ``Airplanes with Airplane 
Information Management System (AIMS)-2 with a requirement to 
incorporate service bulletin 777-31-0294.''
    (4) Where the description in the Effectivity section of Boeing 
Alert Requirements Bulletin 777-31A0342 RB, dated July 19, 2021, 
defines Group 2 airplanes as ``Airplanes with AIMS-2 with service 
bulletin 777-31-0331 incorporated,'' this AD requires using 
``Airplanes with AIMS-2 with a requirement to incorporate service 
bulletin 777-31-0331.''
    (5) Where the description in the Effectivity section of Boeing 
Alert Requirements Bulletin 777-31A0342 RB, dated July 19, 2021, 
defines Group 3 airplanes as ``Airplanes with AIMS-2 with service 
bulletin 777-31-0332 incorporated,'' this AD requires using 
``Airplanes with AIMS-2 with a requirement to incorporate service 
bulletin 777-31-0332.''
    (6) Where the description in the Effectivity section of Boeing 
Alert Requirements Bulletin 777-31A0342 RB, dated July 19, 2021, 
defines Group 5 airplanes as ``Airplanes with Airplane Information 
Management System (AIMS)-,'' this AD requires using ``Airplanes with 
Airplane Information Management System (AIMS)-1 and airplanes 
equipped with AIMS-2 that are not in Group 1, 2, 3, or 4.'' (That 
is, there are two subsets of Group 5 airplanes with different 
required actions.) For airplanes, that, as of the effective date of 
this AD, are equipped with AIMS-2 and are not in Group 1, 2, 3 or 4, 
this AD does not require Action 1 of Table 3 of the Accomplishment 
Instructions of Boeing Alert Requirements Bulletin 777-31A0342 RB, 
dated July 19, 2021.

(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 Doug Tsuji, 
Aviation Safety Engineer, FAA, 2200 South 216th St., Des Moines, WA 
98198; phone: 206-231-3548; email: [email protected].
    (2) Service information identified in this AD that is not 
incorporated by reference is available at the addresses specified in 
paragraphs (k)(3) and (4) of 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 777-31A0342 RB, dated 
July 19, 2021.
    (ii) [Reserved]
    (3) For service information 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 service information 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 February 21, 2024.
Victor Wicklund,
Deputy Director, Compliance & Airworthiness Division, Aircraft 
Certification Service.
[FR Doc. 2024-05497 Filed 3-18-24; 8:45 am]
BILLING CODE 4910-13-P