[4910-13-P]
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2024-1699; Project Identifier AD-2023-01084-T]
RIN 2120-AA64
Airworthiness Directives; The Boeing Company Airplanes
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Notice of proposed rulemaking (NPRM).
SUMMARY: The FAA proposes to adopt a new airworthiness directive (AD) for certain
The Boeing Company Model 767-200, -300, and -400ER series airplanes. This proposed
AD was prompted by a report of multiple engine indicating and crew alerting system
messages during the potable water servicing for a Model 777 freighter airplane after the
water leaked onto the electronics equipment cooling air filter. Since the Model 767
passenger airplanes are similar in design, we are issuing an AD against the Model 767
passenger airplanes. This proposed AD would require installation of hoseducts around the
left-side section 43 potable water supply hoses and connections, a potable water system
leakage test, and applicable corrective actions. The FAA is proposing this AD to address
the unsafe condition on these products.
DATES: The FAA must receive comments on this proposed AD by [INSERT DATE 45
DAYS AFTER DATE OF PUBLICATION IN THE FEDERAL REGISTER].
ADDRESSES: You may send comments, using the procedures found in 14 CFR 11.43
and 11.45, by any of the following methods:
• Federal eRulemaking Portal: Go to regulations.gov. Follow the instructions for
submitting comments.
• Fax: 202-493-2251.

• Mail: U.S. Department of Transportation, Docket Operations, M-30, West
Building Ground Floor, Room W12-140, 1200 New Jersey Avenue SE, Washington, DC
20590.
• Hand Delivery: Deliver to Mail address above between 9 a.m. and 5 p.m.,
Monday through Friday, except Federal holidays.
AD Docket: You may examine the AD docket at regulations.gov under Docket No. FAA2024-1699; 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 NPRM, any
comments received, and other information. The street address for Docket Operations is
listed above.
Material Incorporated by Reference:
• For service information, 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-2024-1699.
FOR FURTHER INFORMATION CONTACT: Brandon Lucero, Aviation Safety
Engineer, FAA, 2200 South 216th St., Des Moines, WA 98198; phone: 206-231-3569;
email: Brandon.Lucero@faa.gov.
SUPPLEMENTARY INFORMATION:
Comments Invited
The FAA invites you to send any written relevant data, views, or arguments about
this proposal. Send your comments to an address listed under ADDRESSES. Include
“Docket No. FAA-2024-1699; Project Identifier AD-2023-01084-T” at the beginning of

your comments. The most helpful comments reference a specific portion of the proposal,
explain the reason for any recommended change, and include supporting data. The FAA
will consider all comments received by the closing date and may amend this proposal
because of those comments.
Except for Confidential Business Information (CBI) as described in the following
paragraph, and other information as described in 14 CFR 11.35, the FAA will post all
comments received, without change, to regulations.gov, including any personal
information you provide. The agency will also post a report summarizing each
substantive verbal contact received about this NPRM.
Confidential Business Information
CBI is commercial or financial information that is both customarily and actually
treated as private by its owner. Under the Freedom of Information Act (FOIA) (5 U.S.C.
552), CBI is exempt from public disclosure. If your comments responsive to this NPRM
contain commercial or financial information that is customarily treated as private, that
you actually treat as private, and that is relevant or responsive to this NPRM, it is
important that you clearly designate the submitted comments as CBI. Please mark each
page of your submission containing CBI as “PROPIN.” The FAA will treat such marked
submissions as confidential under the FOIA, and they will not be placed in the public
docket of this NPRM. Submissions containing CBI should be sent to Brandon Lucero,
Aviation Safety Engineer, FAA, 2200 South 216th St., Des Moines, WA 98198; phone:
206-231-3569; email: Brandon.Lucero@faa.gov. Any commentary that the FAA receives
that is not specifically designated as CBI will be placed in the public docket for this
rulemaking.
Background
The FAA has received a report of multiple engine indicating and crew alerting
system messages during the potable water servicing for a Model 777 freighter airplane.

The cause was found to be the separation of a fitting and steel water supply tube at a
location above an electronics equipment cooling air filter, behind the forward cargo
compartment left sidewall. The water from the soaked filter was then blown by the
equipment cooling system onto multiple line replaceable units in the main electronics
center. Model 767 passenger airplanes are similar in design to Model 777 freighter
airplane. Model 767 passenger airplanes pull air with a fan from the area behind the
forward cargo compartment left sidewall through an inlet screen and duct to cool main
electronics center components. Model 767 passenger airplanes use potable water supply
hoses with inner tubes made of flexible silicone-lined polymer and outer tubes made of
steel braid at locations typically below the equipment cooling supply air inlet. Also, some
Model 767 passenger airplane configurations have potable water system fitting
connections and water supply hose routing near the equipment cooling supply air inlet
and/or water supply hose routing at locations above it. The water leakage from the
potable water system near the equipment cooling supply air inlet, if not addressed, could
damage main electronics center components and result in loss of continued safe flight and
landing.
FAA’s Determination
The FAA is issuing this NPRM after determining that the unsafe condition
described previously is likely to exist or develop on other products of the same type
design.
Related Service Information under 1 CFR Part 51
The FAA reviewed Boeing Alert Requirements Bulletin 767-38A0076 RB, dated
December 1, 2023. This service information specifies procedures for the following
actions at the lower lobe section 43 potable water system plumbing on left side:
• Installing hoseducts and support clamps.

• Installing spray shields, new tie straps on the supply hose, and tee fitting
shrouds, depending on the airplane configuration.
• Replacing the supply hoses and tee fittings for certain airplane configurations.
• Doing a potable water system leakage test and, for any leakage found, repeating
the test until no leakage 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.
Proposed AD Requirements in this NPRM
This proposed AD would require accomplishing the actions specified in the
service information already described, and except for any differences identified as
exceptions in the regulatory text of this proposed AD. For information on the procedures
and compliance times, see this service information at regulations.gov under Docket No.
FAA-2024-1699.
Costs of Compliance
The FAA estimates that this AD, if adopted as proposed, would affect 397
airplanes of U.S. registry. The FAA estimates the following costs to comply with this
proposed AD:
Estimated costs
Action

Labor cost

Parts cost

Cost per
product

Cost on U.S.
operators

Install hose ducts,
connections, and
leakage test

Up to 19 work-hours
X $85 per hour =
$1,615

Up to $1,130

$2,745

$1,089,765

The FAA has included all known costs in its cost estimate. According to the
manufacturer, however, some or all of the costs of this proposed 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
The FAA determined that this proposed AD would not have federalism
implications under Executive Order 13132. This proposed AD would 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 this proposed regulation:
(1) Is not a “significant regulatory action” under Executive Order 12866,
(2) Would not affect intrastate aviation in Alaska, and
(3) Would 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 Proposed Amendment
Accordingly, under the authority delegated to me by the Administrator, the FAA
proposes to amend 14 CFR part 39 as follows:
PART 39 - AIRWORTHINESS DIRECTIVES
1. The authority citation for part 39 continues to read as follows:
Authority: 49 U.S.C. 106(g), 40113, 44701.
§ 39.13 [Amended]
2. The FAA amends § 39.13 by adding the following new airworthiness directive:
The Boeing Company: Docket No. FAA-2024-1699; Project Identifier AD-2023-01084T.
(a) Comments Due Date
The FAA must receive comments on this airworthiness directive (AD) by
[INSERT DATE 45 DAYS AFTER DATE OF PUBLICATION IN THE FEDERAL
REGISTER].
(b) Affected ADs
None.
(c) Applicability
This AD applies to The Boeing Company Model 767-200, -300, and -400ER
series airplanes, as identified in Boeing Alert Requirements Bulletin 767-38A0076 RB,
dated December 1, 2023.
(d) Subject
Air Transport Association (ATA) of America Code 38, Water/waste.
(e) Unsafe Condition
This AD was prompted by a report of multiple engine indicating and crew alerting
system messages during the potable water servicing for a Model 777 freighter airplane
after the water leaked onto the electronics equipment cooling air filter. The FAA is

issuing this AD to address water leakage from the potable water system near the
equipment cooling supply air inlet. The unsafe condition, if not addressed, could damage
main electronics center components and result in 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 time specified
in the “Compliance” paragraph of Boeing Alert Requirements Bulletin 767-38A0076 RB,
dated December 1, 2023, do all applicable actions identified in, and in accordance with,
the Accomplishment Instructions of Boeing Alert Requirements Bulletin 767-38A0076
RB, dated December 1, 2023.
Note 1 to paragraph (g): Guidance for accomplishing the actions required by
this AD can be found in Boeing Alert Service Bulletin 767-38A0076, dated December 1,
2023, which is referred to in Boeing Alert Requirements Bulletin 767-38A0076 RB,
dated December 1, 2023.
(h) Exception to Service Information Specifications
Where the Boeing Recommended Compliance Time columns of the tables in the
“Compliance” paragraph of Boeing Alert Requirements Bulletin 767-38A0076 RB, dated
December 1, 2023, refer to “the Original Issue date of Requirements Bulletin
767-38A0076 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: AMOC@faa.gov.
(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 Brandon Lucero, Aviation Safety
Engineer, FAA, 2200 South 216th St., Des Moines, WA 98198; phone: 206-231-3569;
email: Brandon.Lucero@faa.gov.
(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 767-38A0076 RB, dated December 1,
2023.
(ii) [Reserved]

(3) For service information, 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
fr.inspection@nara.gov.
Issued on June 20, 2024.

Suzanne Masterson,
Deputy Director, Integrated Certificate Management Division,
Aircraft Certification Service.
[FR Doc. 2024-13994 Filed: 6/25/2024 8:45 am; Publication Date: 6/26/2024]