[Federal Register Volume 89, Number 22 (Thursday, February 1, 2024)]
[Rules and Regulations]
[Pages 6416-6419]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2024-01970]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2023-0429; Project Identifier AD-2022-00775-T; 
Amendment 39-22658; AD 2024-01-07]
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 all 
The Boeing Company Model 777 airplanes. This AD was prompted by an 
evaluation by the design approval holder (DAH) that found the force 
limiter assemblies for the lateral control mechanism are not breaking 
out within the maximum design force requirements. This AD requires 
replacing affected force limiter assemblies and prohibits the 
installation of affected parts. The FAA is issuing this AD to address 
the unsafe condition on these products.

DATES: This AD is effective March 7, 2024.
    The Director of the Federal Register approved the incorporation by 
reference of a certain publication listed in this AD as of March 7, 
2024.

ADDRESSES: 
    AD Docket: You may examine the AD docket at regulations.gov under 
Docket No. FAA-2023-0429; 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-2023-0429.

FOR FURTHER INFORMATION CONTACT: Anthony Caldejon, Aviation Safety 
Engineer, FAA, 2200 South 216th St., Des Moines, WA 98198; telephone 
206-231-3534; 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 airplanes. The NPRM published in the Federal Register on 
March 27, 2023 (88 FR 18099). The NPRM was prompted by an evaluation by 
the DAH that found the force limiter assemblies for the lateral control 
mechanism are not breaking out within the maximum design force 
requirements. In the NPRM, the FAA proposed to require identifying and 
replacing affected force limiter assemblies, and to prohibit the 
installation of affected parts.
    The FAA is issuing this AD to address the force limiter assemblies 
not breaking out within the maximum design force requirements. The 
unsafe condition, combined with a lateral control system jam or 
restriction, could result in the loss of lateral control from the wheel 
and potentially affect continued safe flight and landing.

Discussion of Final Airworthiness Directive

Comments

    The FAA received comments from the Air Line Pilots Association, 
International, who supported the NPRM without change.
    The FAA received additional comments from Aerologic, All Nippon 
Airways, American Airlines, Boeing, China Airlines, FedEx, Omni Air 
International (Omni Air), Swiss International Air Lines (Swiss Air), 
Turkish Airlines, and United Airlines. The following presents those 
comments and the FAA's response to each comment.

Request To Revise Requirements for Certain Line Numbers

    Aerologic, All Nippon Airways, American Airlines, Boeing, Omni Air, 
United Airlines, and Swiss Air requested changes to the proposed AD to 
provide relief for airplane line numbers prior to 1531. Aerologic, 
Boeing, and American Airlines also requested changes to provide relief 
for airplane lines number after 1707. Boeing stated that the suspect 
affected force limiter assemblies were delivered only

[[Page 6417]]

on airplane line numbers 1531 through 1707, and the risk of rotability 
on other line numbers is low.
    Boeing requested that a records inspection be added for airplane 
line numbers prior to 1531 to determine prior replacement of a force 
limiter assembly, and to require installation of a force limiter 
assembly P/N 253W1263-3 only if any force limiter assembly P/N 
253W1263-1 had been replaced. Boeing stated that if no prior 
replacement of a force limiter assembly has been recorded on an 
airplane before line number 1531, the risk of having an affected part 
installed is low. Boeing reported that no force limiter assembly P/N 
253W1263-1 has been purchased since 2012 and contended that the use of 
force limiter assembly P/N 253W1263-1 for rotable parts is extremely 
low. Boeing also noted that force limiter assemblies P/N 253W1263-3 are 
already installed on airplane line numbers 1708 and subsequent and 
cannot be replaced by force limiter assemblies P/N 253W1263-1 in 
accordance with the drawing interchangeability.
    Omni Air proposed alternative requirements for airplane line 
numbers prior to 1531: repetitive operational checks of the wheel jam 
breakout mechanism in accordance with MPD task 27-190-00, and 
replacement with a force limiter assembly P/N 253W1263-3 for a failed 
operational check or as terminating action. Omni Air also proposed a 
one-time operational check of the wheel jam breakout mechanism in 
accordance with the MPD task if there are no concerns about the force 
limiter assembly being replaced since the last check. Omni stated that 
Boeing found that force limiter assemblies P/N 253W1263-1 delivered on 
airplane line numbers prior to 1531 were functioning properly.
    Aerologic interpreted the effectivity of the Requirements Bulletin 
to be based on production testing of the force limiter assembly break-
out forces changing the amount of applied corrosion inhibiting compound 
(CIC) causing the unsafe condition. Therefore, Aerologic stated that 
Boeing should be able to identify affected force limiter assemblies P/N 
253W1263-1 either by serial number or batch number and differentiate 
acceptable and unsafe parts. Therefore, Aerologic requested that the 
FAA issue a separate AD action to test the break-out forces of force 
limiter assemblies P/N 253W1263-1 on airplanes not identified in the 
Boeing Alert Requirements Bulletin 777-27A0124 RB, dated October 27, 
2021. Aerologic proposed requiring a check of the serial number of the 
force limiter assembly on all Model 777 airplanes to determine which 
affected units should be replaced. Also, Aerologic proposed on-wing 
testing of the breakout force as an alternative to the proposed 
replacement of all force limiter assemblies P/N 253W1263-1 on all Model 
777 airplanes because the actions would not be possible within the 
proposed compliance time of the NPRM.
    All Nippon Airways questioned whether the intent of the proposed AD 
is to eliminate all force limiter assemblies P/N 253W1263-1, since 
Boeing has determined that replacement is not necessary if that part 
passed the functional test on delivery. All Nippon Airways suggested 
that operators will be significantly affected under the unrealistic 
proposed compliance time of 12 months and requested that the AD 
requirements be revised so that only the target units identified in 
Boeing Alert Requirements Bulletin 777-27A0124 RB, dated October 27, 
2021, are required to be replaced.
    American Airlines proposed creating two groups of airplanes: Group 
1, for Model 777 airplanes with line numbers 1531 through 1707 (the 
effectivity of Boeing Alert Requirements Bulletin 777-27A0124 RB, dated 
October 27, 2021), and Group 2, for Model 777 airplanes not identified 
in the Requirements Bulletin. American Airlines stated that it has had 
zero replacements of P/N 253W1263-1 in 24 years of service of its 
fleet, which are all prior to line number 1531. American Airlines also 
stated that the illustrated parts catalog (IPC) shows that P/N 
253W1263-1 is interchangeable one-way forward only with P/N 253W1263-3. 
American Airlines further recommended creating subgroups for Group 2. 
For subgroup 2a, airplanes for which it can conclusively be shown that 
the force limiter assembly P/N 253W1263-1 has never been replaced, no 
further action would be required. And for subgroup 2b, airplanes for 
which it cannot be conclusively shown that the force limiter assembly 
P/N 253W1263-1 was never replaced, the AD would require replacement 
with force limiter assembly P/N 253W1263-3.
    Swiss Air requested that the proposed AD allow a records review on 
airplanes prior to line number 1531 to determine whether an assembly 
with force limiter assembly P/N 253W1263-1 was installed. Swiss Air 
further requested that the proposed AD allow testing of force limiter 
assemblies with P/N 253W1263-1 with unknown history to measure the 
break-out force and allow return to service if the force is within the 
drawing requirements. United Airlines also requested that testing 
verifying serviceability on airplanes with line numbers prior to 1531 
be considered acceptable.
    The FAA partially agrees with the requests. The FAA agrees to 
exclude airplane line numbers prior to 1531 and after 1707 from the 
replacement requirement if any installed force limiter assembly P/N 
253W1263-1 had not been previously replaced. Limiting the replacement 
requirement in this way was the original intent of the AD. The FAA 
disagrees, however, with Aerologic's request to revise paragraph (c) of 
this AD to limit the AD requirements to airplanes having line numbers 
in the effectivity of Boeing Alert Requirements Bulletin 777-27A0124 
RB, dated October 27, 2021. The NPRM, under ``Differences Between This 
Proposed AD and the Service Information,'' stated that the 
applicability of the AD differed from the effectivity of Boeing Alert 
Requirements Bulletin 777-27A0124 RB, dated October 27, 2021, because 
the affected parts are rotable parts, and the FAA has determined that 
these parts could later be installed on airplanes that were initially 
delivered with acceptable parts, thereby subjecting those airplanes to 
the unsafe condition. Although the IPC states that force limiter 
assembly P/N 253W1263-3 cannot be replaced with P/N 253W1263-1, it is 
possible for an operator to do so. Therefore, paragraph (i) of this AD, 
``Parts Installation Prohibition,'' applies to all Model 777 airplanes.
    The FAA disagrees to include testing as a method of verifying a 
functional force limiter assembly because the FAA has revised paragraph 
(g) of this AD so that it applies only to (1) airplanes identified in 
Boeing Alert Requirements Bulletin 777-27A0124 RB, dated October 27, 
2021, and (2) airplanes not identified in Boeing Alert Requirements 
Bulletin 777-27A0124 RB, dated October 27, 2021, on which the force 
limiter assembly was replaced with P/N 253W1263-1. This should 
alleviate the demand for replacement force limiter assemblies P/N 
253W1263-3. The FAA further disagrees to create a separate AD for 
airplane line numbers prior to 1531 because of the urgency of the 
unsafe condition and the delay that would be caused by additional 
rulemaking. The FAA has also determined that, in light of the changes 
to this AD, a separate AD is not necessary.

Request To Extend Compliance Time

    Aerologic, All Nippon Airways, China Airlines, FedEx, Swiss Air, 
Turkish Airlines, and United Airlines expressed concern that long lead 
times (300 days,

[[Page 6418]]

per Boeing, as specified by FedEx, Turkish Airlines, and China 
Airlines) for the new force limiter assemblies P/N 253W1263-3 would 
make it difficult to replace force limiter assemblies P/N 253W1263-1 
within 12 months.
    The FAA acknowledges that it could be difficult to replace all 
force limiter assemblies P/N 253W1263-1 within the 12-month compliance 
period because of the long lead time of procurement and the large 
quantity of spares having P/N 253W1263-3 necessary to be available to 
satisfy the global fleet. The FAA disagrees, however, to revise the 
compliance time because the replacement requirement is limited to force 
limiter assemblies P/N 253W1263-1 only on airplane line numbers 1531 
through 1707 and on airplanes on which the original force limiter 
assembly had been replaced. However, an operator unable to meet the 
compliance time required by this AD may request approval of an 
alternative method of compliance (AMOC) under the provisions of 
paragraph (j) of this AD, if sufficient data are submitted to 
substantiate that such an extension would provide an acceptable level 
of safety. The FAA has not changed this AD further.

Request To Clarify Effect of Unsafe Condition

    Boeing requested that the proposed AD be revised to clarify the 
unsafe condition and its potential safety impact, which, Boeing 
asserted, could be inferred as a loss of lateral control during normal 
flight conditions. Boeing stated that the unsafe condition occurs only 
with an affected force limiter assembly and a jam/restriction of the 
lateral controls, when the pilot needs to override a lateral control 
restriction. Boeing therefore requested that the Background section of 
the NPRM be revised to state that if a jam/restriction occurs on one 
side of the lateral controls on an airplane with an affected force 
limiter assembly, the pilot may not be able to override the jam 
preventing lateral control from the wheel. Boeing further requested 
that the proposed AD be revised to clarify that the unsafe condition 
could result in the loss of lateral control from the wheel and 
potentially affect continued safe flight and landing only when combined 
with a lateral control system restriction.
    The FAA concurs with the request and has revised relevant sections 
of this AD accordingly.

Request To Define ``Installation'' of Parts

    American Airlines requested that the proposed AD be clarified to 
state that removal of a force limiter assembly P/N 253W1263-1 for other 
maintenance and reinstallation of that same part on the same airplane 
will not be considered as an installation as defined in paragraph (i) 
of the proposed AD, ``Parts Installation Prohibition.''
    The FAA infers that this additional clarification is requested to 
prevent the unnecessary removal and replacement of force limiter 
assemblies P/N 253W1263-1 that have been previously verified as being 
outside the suspect affected range and considered functional. The FAA 
acknowledges the commenter's concern, and provides the following 
clarification of the requirement. Once the FAA has determined that an 
unsafe condition exists, the FAA generally ensures that that condition 
not be allowed to be introduced into the fleet. Although the word 
``install'' is generally considered to be broader than the word 
``replace,'' operators can interpret ``install'' in this AD as meaning 
``replace'' while remaining within the intent of paragraph (i) of this 
AD. By simply reinstalling a part removed during maintenance, the 
operator is not ``installing'' a different part. Therefore, this AD 
allows operators to remove a part and then re-install that same part 
for other maintenance activities not associated with this AD. The FAA 
has not changed this AD as a result of this comment.

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 777-27A0124 RB, 
dated October 27, 2021. This service information specifies procedures 
for replacing the lower and upper force limiter assemblies P/N 
253W1263-1 with force limiter assemblies P/N 253W1263-3. 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
----------------------------------------------------------------------------------------------------------------
                                                                          Cost per
             Action                  Labor cost         Parts cost        product        Cost on U.S. operators
----------------------------------------------------------------------------------------------------------------
Replacement....................  7 work-hours x $85          $8,960           $9,555   Up to $3,372,915.
                                  per hour = $595.
----------------------------------------------------------------------------------------------------------------

    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

[[Page 6419]]

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:

2024-01-07 The Boeing Company: Amendment 39-22658; Docket No. FAA-
2023-0429; Project Identifier AD-2022-00775-T.

(a) Effective Date

    This airworthiness directive (AD) is effective March 7, 2024.

(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 27, Flight 
controls.

(e) Unsafe Condition

    This AD was prompted by an evaluation by the design approval 
holder that the force limiter assemblies for the lateral control 
mechanism are not breaking out within the maximum design force 
requirements. The FAA is issuing this AD to address the force 
limiter assemblies not breaking out within the maximum design force 
requirements. The unsafe condition, combined with a lateral control 
system jam or restriction, could result in the loss of lateral 
control from the wheel and potentially affect continued safe flight 
and landing.

(f) Compliance

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

(g) Required Actions

    For airplanes identified in paragraphs (g)(1) and (2) of this 
AD: Except as specified by paragraph (h) of this AD, at the 
applicable times specified in the ``Compliance'' paragraph of Boeing 
Alert Requirements Bulletin 777-27A0124 RB, dated October 27, 2021, 
do all applicable actions identified in, and in accordance with, the 
Accomplishment Instructions of Boeing Alert Requirements Bulletin 
777-27A0124 RB, dated October 27, 2021.
    (1) Airplanes identified in Boeing Alert Requirements Bulletin 
777-27A0124 RB, dated October 27, 2021.
    (2) Airplanes not identified in Boeing Alert Requirements 
Bulletin 777-27A0124 RB, dated October 27, 2021, that have an 
original airworthiness certificate or original export certificate of 
airworthiness issued on or before the effective date of this AD, and 
on which a force limiter assembly P/N 253W1263-1 or P/N 253W1263-3 
installed in production has been replaced with P/N 253W1263-1.
    Note 1 to paragraph (g): Guidance for accomplishing the actions 
required by this AD can be found in Boeing Alert Service Bulletin 
777-27A0124 RB, dated October 27, 2021, which is referred to in 
Boeing Alert Requirements Bulletin 77-27A0124 RB, dated October 27, 
2021.

(h) Exceptions to Service Information Specifications

    Where the Compliance Time columns of the tables in the 
``Compliance'' paragraph of Boeing Alert Requirements Bulletin 777-
27A0124 RB, dated October 27, 2021, use the phrase ``the original 
issue date of Requirements Bulletin 777-27A0124 RB,'' this AD 
requires using ``the effective date of this AD.''

(i) Parts Installation Prohibition

    As of the effective date of this AD, no person may install a 
force limiter assembly, P/N 253W1263-1, on any airplane.

(j) 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 (k) 
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.

(k) Related Information

    For more information about this AD, contact Anthony Caldejon, 
Aviation Safety Engineer, FAA, 2200 South 216th St., Des Moines, WA 
98198; telephone 206-231-3534; email [email protected].

(l) 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 777-27A0124 RB, dated 
October 27, 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/[email protected]">www.archives.gov/federal-register/cfr/[email protected].

    Issued on January 6, 2024.
Caitlin Locke,
Director, Compliance & Airworthiness Division, Aircraft Certification 
Service.
[FR Doc. 2024-01970 Filed 1-31-24; 8:45 am]
BILLING CODE 4910-13-P