[Federal Register Volume 89, Number 22 (Thursday, February 1, 2024)]
[Rules and Regulations]
[Pages 6422-6425]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2024-01967]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2023-0657; Project Identifier AD-2022-01351-T; 
Amendment 39-22652; AD 2024-01-01]
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 (Boeing) Model 787-8, 787-9, and 787-10 
airplanes. This AD was prompted by reports of undetected water leaks 
from the faucet control module (FCM) migrating below the passenger 
floor in multiple lavatory locations during flight, and into the 
electronic equipment bay(s). This AD requires repetitive general visual 
inspections of the area under all lavatory washbasins for evidence of 
intermittent and active leaks at the FCM and applicable on-condition 
actions. 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-2023-0657; 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-2023-0657.

FOR FURTHER INFORMATION CONTACT: Courtney Tuck, Aviation Safety 
Engineer, FAA, 2200 South 216th St., Des Moines, WA 98198; telephone 
206-231-3986; 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 Boeing Model 787-8, 
787-9, and 787-10 airplanes. The NPRM published in the Federal Register 
on April 10, 2023 (88 FR 21120). The NPRM was prompted by reports of 
undetected water leaks from the FCM migrating below the passenger floor 
in multiple lavatory locations during flight, and into the electronic 
equipment bay(s). In the NPRM, the FAA advised that the FCMs are 
located under the sinks in each lavatory and have an O-ring seal at the 
top of the FCM mixing chamber; a small amount of water leaking past the 
O-ring has been identified as the source of the leak.
    In the NPRM, the FAA proposed to require repetitive general visual 
inspections of the area under all lavatory washbasins for evidence of 
intermittent and active leaks at the FCM and applicable on-condition 
actions, including replacing the affected FCM.

[[Page 6423]]

The FAA is issuing this AD to address undetected water leaks, which 
could damage flight critical equipment. The unsafe condition, if not 
addressed, could result in loss of multiple line replaceable units 
(LRUs) and subsequent loss of continued safe flight and landing.

Discussion of Final Airworthiness Directive

Comments

    The FAA received comments from Boeing and the Air Line Pilots 
Association, International, who supported the NPRM without change.
    The FAA received additional comments from United Airlines (UAL), 
American Airlines (American), and All Nippon Airways (ANA). The 
following presents the comments received on the NPRM and the FAA's 
response to each comment.

Request To Allow Alternative Cleaning Material

    UAL noted that the proposed AD would require complying with the 
actions in table 1 of Boeing Alert Requirements Bulletin B787-81205-
SB250290-00 RB, Issue 001, dated November 1, 2022, which then 
references the procedures in Service Bulletin B787-81205-SB250290-00 
Issue 001 or later approved issues for each action. UAL stated that the 
service bulletin contains a cleaning action that refers to a Jamco 
component maintenance manual (CMM) as an accepted procedure. UAL 
further stated that the instructions in the Jamco CMM for removing 
scale specify using a corrosive solution that can produce harmful 
fumes. As a result, UAL asked to use a milder product as an 
alternative.
    Both the requirements bulletin and the service bulletin state that 
where the instructions refer to another document, operators may use 
accepted alternative procedures. Where the instructions state a 
procedure must done in accordance with a Boeing document, then 
operators will need an alternative method of compliance (AMOC) to use a 
different procedure. Because the cleaning procedure mentioned by the 
commenter refers to the Jamco CMM, operators may use accepted 
alternative procedures, including a different accepted cleaning 
product, without obtaining an AMOC. No change to the AD is necessary as 
a result of this comment.

Request To Limit Inspection Area

    In the NPRM, the FAA proposed to require visual inspections at all 
lavatory locations. American and ANA requested that the FAA limit the 
inspection to the area under the lavatory washbasins located in the 
door 1 and door 3 area near the electronic equipment bays. American 
added that leaks in other locations do not have the potential to cause 
damage to the LRUs and thus do not affect safe operation of the 
airplane.
    The FAA disagrees with the commenters' request. The unsafe 
condition exists when two FCMs leak simultaneously, involving the loss 
of flight-critical equipment at different locations. This could occur 
at door 1, 2, 3, or 4. Further, it is possible to have multiple 
persistent and simultaneous latent leaks from different lavatories on 
the same airplane. Therefore, it is necessary to inspect the lavatories 
at all locations, not just those near the electronic equipment bays.

Request To Reference Master Minimum Equipment List (MMEL) Item 38-10-
01A

    American requested that the FAA state that MMEL item 38-10-01A 
(which allows individual components of the potable water system to be 
inoperative provided associated components are deactivated or isolated 
and associated system components are verified to not have leaks) 
remains valid and applicable as a method to deactivate the water supply 
to a discrepant FCM.
    The FAA agrees that this AD does not conflict with an operator's 
ability to dispatch an airplane with an inoperable potable water system 
under MMEL item 38-10-01A. The FAA has not changed this AD in this 
regard.

Request To Limit Actions for Intermittent Leaks

    ANA requested that the FAA revise the proposed AD to not require 
corrective action if intermittent leaks are found from the FCM. ANA 
stated that if evidence of intermittent leaks are found at the FCM, the 
source of the leak isn't necessarily the FCM, and therefore it should 
not be necessary to replace the FCM or deactivate the water supply to 
the FCM.
    The FAA disagrees. Intermittent leaks may have a long latency 
period and be difficult to detect, but they can still cause the unsafe 
condition identified in this AD and therefore must be addressed. 
Operators with a method other than replacement of the FCM, which 
provides an acceptable level of safety, may request approval to use an 
AMOC. The FAA did not change this AD as a result of this request.

Additional Changes to This Final Rule

    After the NPRM was published, Boeing notified the FAA that certain 
airplanes were modified in production and delivered with a redesigned 
FCM that is not subject to the unsafe condition. The FAA has determined 
the actions required by this AD are not necessary on those airplanes 
and has therefore revised the applicability of this AD to only include 
airplanes that were delivered with the affected FCM.

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 the 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 B787-81205-
SB250290-00 RB, Issue 001, dated November 1, 2022. This service 
information specifies procedures for a repetitive general visual 
inspection of the area under all lavatory washbasins for evidence of 
intermittent and active leaks at the FCM and applicable on-condition 
actions. On-condition actions include replacing the affected FCM with 
new or serviceable FCM at affected lavatory washbasin(s), and doing a 
leak test. If a leak is found, the service information specifies doing 
applicable corrective action, repeating the leak test, and making sure 
no leak is found.
    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.

Differences Between This AD and the Service Information

    The effectivity of Boeing Alert Requirements Bulletin B787-81205-
SB250290-00 RB, Issue 001, dated November 1, 2022, is Model 787-8, -9, 
and -10 airplanes, line numbers 6 through 9996. As the FAA stated in 
the NPRM, the agency would consider revising the applicability of the 
final rule to exclude airplanes with a redesigned FCM that eliminates 
the need for the actions required by this AD. Therefore, the 
applicability of this AD does not include those line-numbered airplanes 
with a redesigned FCM installed in production.

Interim Action

    This AD is an interim action. The FAA is considering additional 
rulemaking regarding the redesigned

[[Page 6424]]

FCM that addresses the unsafe condition identified in this AD.

Costs of Compliance

    The FAA estimates that this AD affects 140 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
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Inspection......................  1 work-hour x $85 per                 $0   $85 per inspection         $11,900
                                   hour = $85 per                             cycle.
                                   inspection cycle.
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    The FAA estimates the following costs to do any necessary 
replacements 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 replacements:

                                               On-Condition Costs
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                                                                                                     Cost per
                  Action                                Labor cost                 Parts cost        product
----------------------------------------------------------------------------------------------------------------
Replacement...............................  1 work-hour x $85 per hour = $85..          $6,021           $6,106
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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:

2024-01-01 The Boeing Company: Amendment 39-22652; Docket No. FAA-
2023-0657; Project Identifier AD-2022-01351-T.

(a) Effective Date

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

(b) Affected ADs

    None.

(c) Applicability

    This AD applies to The Boeing Company Model 787-8, 787-9, and 
787-10 airplanes, certificated in any category, having line numbers 
6 through 687 inclusive, 689 through 954 inclusive, 956 through 970 
inclusive, 972 through 982 inclusive, 984 through 989 inclusive, 991 
through 996 inclusive, 999, 1001 through 1008 inclusive, 1012, 1013, 
1016 through 1019 inclusive, 1021, 1022, 1024 through 1026 
inclusive, 1029 through 1032 inclusive, 1038, 1040, 1041, 1044, 
1045, 1047, 1048, 1054 through 1062 inclusive, 1071, 1072, 1074, 
1075, 1082, 1085, 1087, 1091, 1094, 1095, 1098, 1099, 1103, 1109, 
1112 through 1114 inclusive, 1117, 1118, 1121, 1122, 1125, 1126, 
1128 through 1134 inclusive, 1136 through 1145 inclusive, 1147, 
1148, 1151, 1161, and 1167.

(d) Subject

    Air Transport Association (ATA) of America Code 38, Water/waste.

(e) Unsafe Condition

    This AD was prompted by reports of undetected water leaks from 
the faucet control module migrating below the passenger floor in 
multiple lavatory locations during flight, and into the electronic 
equipment bay(s). The FAA is issuing this AD to address undetected 
water leaks, which could damage flight critical equipment. The 
unsafe condition, if not addressed, could result in loss of multiple 
line replaceable units and subsequent loss of continued safe flight 
and landing.

(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 B787-81205-SB250290-00 RB, Issue 001, 
dated November 1, 2022, do all applicable actions identified in, and 
in accordance with, the Accomplishment Instructions of Boeing Alert 
Requirements Bulletin B787-81205-SB250290-00 RB, Issue 001, dated 
November 1, 2022.
    Note 1 to paragraph (g): Guidance for accomplishing the actions 
required by this AD can be found in Boeing Alert Service Bulletin 
B787-81205-SB250290-00, Issue 001, dated November 1, 2022, which is 
referred to in Boeing Alert Requirements

[[Page 6425]]

Bulletin B787-81205-SB250290-00, Issue 001, dated November 1, 2022.

(h) Exceptions to Service Information Specifications

    Where the Compliance Time column of the table in the 
``Compliance'' paragraph of Boeing Alert Requirements Bulletin B787-
81205-SB250290-00 RB, Issue 001, dated November 1, 2022, uses the 
phrase ``the Issue 001 date of the Requirements Bulletin B787-81205-
SB250290-00 RB,'' this AD requires using ``the effective date of 
this AD.''

(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) 
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

    For more information about this AD, contact Courtney Tuck, 
Aviation Safety Engineer, FAA, 2200 South 216th St., Des Moines, WA 
98198; telephone 206-231-3986; email [email protected].

(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 B787-81205-SB250290-00 
RB, Issue 001, dated November 1, 2022.
    (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 January 3, 2024.
Victor Wicklund,
Deputy Director, Compliance & Airworthiness Division, Aircraft 
Certification Service.
[FR Doc. 2024-01967 Filed 1-31-24; 8:45 am]
BILLING CODE 4910-13-P