[4910-13-P]
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2024-1698; Project Identifier AD-2024-00005-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 767-300F series airplanes. This proposed AD was prompted
by a determination that certain cargo compartment insulation blankets do not adequately
fit some locations and allow smoke to migrate past the cargo compartment sidewall liners
and upward into the main cabin. This proposed AD would require replacing cargo
compartment insulation blankets. 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. FAA2024-1698; 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 identified in this NPRM, 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-2024-1698.
FOR FURTHER INFORMATION CONTACT: Julie Linn, Aviation Safety Engineer,
FAA, 2200 South 216th St., Des Moines, WA 98198; phone: 206-231-3684; email:
julie.linn@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-2024-1698; Project Identifier AD-2024-00005-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 Julie Linn, Aviation
Safety Engineer, FAA, 2200 South 216th St., Des Moines, WA 98198; phone:
206-231-3684; email: julie.linn@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 issued AD 2021-12-11, Amendment 39-21598 (86 FR 33112, June 24,
2021) (AD 2021-12-11), for certain The Boeing Company Model 767-200, -300, -300F,
and -400ER series airplanes. AD 2021-12-11 was prompted by a report of a fire in the
bilge area of the cargo compartment that burned through the insulation blankets that were
intended to prevent smoke from migrating behind the cargo compartment sidewall liners

and upward into the main cabin. AD 2021-12-11 requires replacing the cargo
compartment insulation blankets with new insulation blankets that incorporate fire stops
by complying with Boeing Special Attention Service Bulletin 767-25-0550, Revision 1,
dated December 4, 2019. The FAA issued AD 2021-12-11 to address fire in the bilge
area of the cargo compartment, which if not contained could lead to a smoke and fire
event in the passenger compartment.
Since the FAA issued AD 2021-12-11, the agency determined that for Model
767-300F series airplanes, certain cargo compartment insulation blankets installed by
complying with Boeing Special Attention Service Bulletin 767-25-0550, dated January
30, 2015, and Boeing Special Attention Service Bulletin 767-25-0550, Revision 1, dated
December 4, 2019, do not adequately fit some locations and allow smoke to migrate past
the cargo compartment. Boeing issued Special Attention Service Bulletin 767-25-0550,
Revision 2, dated December 18, 2023, which reduced the affected airplanes and changed
the design of the cargo compartment blankets. The FAA is issuing this NPRM to require
replacing the cargo compartment insulation blankets with newly designed blankets.
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 Special Attention Service Bulletin 767-25-0550,
Revision 2, dated December 18, 2023. This service information specifies procedures for
replacing insulation blankets in the cargo compartment with insulation blankets with
integrated fire stops.

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 identified as “RC”
(required for compliance) in the Accomplishment Instructions of Boeing Special
Attention Service Bulletin 767-25-0550, Revision 2, dated December 18, 2023, already
described, except for any differences identified as exceptions in the regulatory text of this
proposed AD. For information on the procedures, see this service information at
regulations.gov under Docket No. FAA-2024-1698.
Costs of Compliance
The FAA estimates that this AD, if adopted as proposed, would affect 32
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

Replacement

270 work-hours x $85
per hour = $22,950

$35,900

$58,850

$1,883,200

The FAA has included all known costs in its cost estimate. According to the
manufacturer, however, some or all 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-2024-1698; Project Identifier
AD-2024-00005-T.
(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 767-300F series airplanes,
certificated in any category, identified as Group 7, 11 through 15, and 18 in Boeing
Special Attention Service Bulletin 767-25-0550, Revision 2, dated December 18, 2023.
(d) Subject
Air Transport Association (ATA) of America Code 25, Equipment/Furnishings.
(e) Unsafe Condition
This AD was prompted by a determination that certain cargo compartment
insulation blankets do not adequately fit some locations and allow smoke to migrate past
the cargo compartment. The FAA is issuing this AD to require replacing these cargo
compartment insulation blankets. The unsafe condition, if not addressed, could result in a
fire in the bilge area of the cargo compartment, which if not contained could lead to a
smoke and fire event in the passenger compartment.
(f) Compliance
Comply with this AD within the compliance times specified, unless already done.

(g) Required Actions
Within 36 months after the effective date of this AD, do all applicable actions
identified as “RC” (required for compliance) in, and in accordance with, the
Accomplishment Instructions of Boeing Special Attention Service Bulletin 767-25-0550,
Revision 2, dated December 18, 2023.
(h) 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 (i) 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.
(4) For service information that contains steps that are labeled as Required for
Compliance (RC), the provisions of paragraphs (h)(4)(i) and (ii) of this AD apply.
(i) The steps labeled as RC, including substeps under an RC step and any figures
identified in an RC step, must be done to comply with the AD. If a step or substep is

labeled “RC Exempt,” then the RC requirement is removed from that step or substep. An
AMOC is required for any deviations to RC steps, including substeps and identified
figures.
(ii) Steps not labeled as RC may be deviated from using accepted methods in
accordance with the operator’s maintenance or inspection program without obtaining
approval of an AMOC, provided the RC steps, including substeps and identified figures,
can still be done as specified, and the airplane can be put back in an airworthy condition.
(i) Related Information
For more information about this AD, contact Julie Linn, Aviation Safety
Engineer, FAA, 2200 South 216th St., Des Moines, WA 98198; phone: 206-231-3684;
email: julie.linn@faa.gov.
(j) Material Incorporated by Reference
(1) The Director of the Federal Register approved the incorporation by reference
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 material as applicable to do the actions required by this AD,
unless the AD specifies otherwise.
(i) Boeing Special Attention Service Bulletin 767-25-0550, Revision 2, dated
December 18, 2023.
(ii) [Reserved]
(3) For Boeing material, contact Boeing Commercial Airplanes, Attention:
Contractual & Data Services (C&DS), 2600 Westminster Blvd., MC 110-SK57, Seal
Beach, CA 90740-5600; telephone 562-797-1717; website myboeingfleet.com.
(4) You may view this material at the FAA, Airworthiness Products Section,
Operational Safety Branch, 2200 South 216th St., Des Moines, WA. For information on
the availability of this material at the FAA, call 206-231-3195.

(5) You may view this material at the National Archives and Records
Administration (NARA). For information on the availability of this material at NARA,
visit www.archives.gov/federal-register/cfr/ibr-locations or email
fr.inspection@nara.gov.
Issued on June 20, 2024.

Suzanne Masterson,
Deputy Director, Integrated Certificate Management Division,
Aircraft Certification Service.
[FR Doc. 2024-13943 Filed: 6/25/2024 8:45 am; Publication Date: 6/26/2024]