Rule2026-07808
Airworthiness Directives; The Boeing Company Airplanes
Primary source
Metadata and text below are from the Federal Register, a public-domain U.S. government work. Always verify the official published version before relying on it for any legal matter.
Published
April 22, 2026
Effective
May 7, 2026
Issuing agencies
Transportation DepartmentFederal Aviation Administration
Abstract
The FAA is adopting a new airworthiness directive (AD) for The Boeing Company Model 747-400 series airplanes modified by certain supplemental type certificates (STCs). This AD was prompted by a report of a ruptured crew oxygen bottle flexible hose and arcing damage on an adjacent cargo loading system wiring harness. This AD requires a detailed inspection of the crew oxygen bottle flexible hoses and adjacent wire harnesses for chafing and arcing damage and for a minimum clearance between the crew oxygen bottle flexible hoses and adjacent wiring harnesses, and applicable repairs. The FAA is issuing this AD to address the unsafe condition on these products.
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<title>Federal Register, Volume 91 Issue 77 (Wednesday, April 22, 2026)</title>
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[Federal Register Volume 91, Number 77 (Wednesday, April 22, 2026)]
[Rules and Regulations]
[Pages 21373-21375]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2026-07808]
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Rules and Regulations
Federal Register
________________________________________________________________________
This section of the FEDERAL REGISTER contains regulatory documents
having general applicability and legal effect, most of which are keyed
to and codified in the Code of Federal Regulations, which is published
under 50 titles pursuant to 44 U.S.C. 1510.
The Code of Federal Regulations is sold by the Superintendent of Documents.
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Federal Register / Vol. 91 , No. 77 / Wednesday, April 22, 2026 /
Rules and Regulations
[[Page 21373]]
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2026-3486; Project Identifier MCAI-2026-00002-T;
Amendment 39-23314; AD 2026-08-06]
RIN 2120-AA64
Airworthiness Directives; The Boeing Company Airplanes
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Final rule; request for comments.
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SUMMARY: The FAA is adopting a new airworthiness directive (AD) for The
Boeing Company Model 747-400 series airplanes modified by certain
supplemental type certificates (STCs). This AD was prompted by a report
of a ruptured crew oxygen bottle flexible hose and arcing damage on an
adjacent cargo loading system wiring harness. This AD requires a
detailed inspection of the crew oxygen bottle flexible hoses and
adjacent wire harnesses for chafing and arcing damage and for a minimum
clearance between the crew oxygen bottle flexible hoses and adjacent
wiring harnesses, and applicable repairs. The FAA is issuing this AD to
address the unsafe condition on these products.
DATES: This AD is effective May 7, 2026.
The Director of the Federal Register approved the incorporation by
reference of a certain publication listed in this AD as of May 7, 2026.
The FAA must receive comments on this AD by June 8, 2026.
ADDRESSES: You may send comments, using the procedures found in 14 CFR
11.43 and 11.45, by any of the following methods:
<bullet> Federal eRulemaking Portal: Go to <a href="http://regulations.gov">regulations.gov</a>. Follow
the instructions for submitting comments.
<bullet> Fax: 202-493-2251.
<bullet> 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.
<bullet> 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 <a href="http://regulations.gov">regulations.gov</a> under
Docket No. FAA-2026-3486; 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, the mandatory continuing airworthiness
information (MCAI), any comments received, and other information. The
street address for Docket Operations is listed above.
Material Incorporated by Reference:
<bullet> For IAI-Aviation Group material identified in this AD,
contact Israel Aerospace Industries, Ltd., Ben Gurion International
Airport, Israel 7010000; telephone 972-3-9353090; email:
<a href="/cdn-cgi/l/email-protection#0e4f41494c4a454e676f67206d61206762"><span class="__cf_email__" data-cfemail="b7f6f8f0f5f3fcf7ded6de99d4d899dedb">[email protected]</span></a>.
<bullet> 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. It is also available at <a href="http://regulations.gov">regulations.gov</a> under
Docket No. FAA-2026-3486.
FOR FURTHER INFORMATION CONTACT: Narbeh Mardirosian, Aviation Safety
Engineer, FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590;
phone: 562-627-5354; email: <a href="/cdn-cgi/l/email-protection#96f8f7e4f4f3feb8fbf7e4f2ffe4f9e5fff7f8d6f0f7f7b8f1f9e0"><span class="__cf_email__" data-cfemail="026c637060676a2c6f6370666b706d716b636c426463632c656d74">[email protected]</span></a>.
SUPPLEMENTARY INFORMATION:
Comments Invited
The FAA invites you to send any written relevant data, views, or
arguments about this final rule. Send your comments using a method
listed under the ADDRESSES section. Include ``Docket No. FAA-2026-3486;
Project Identifier MCAI-2026-00002-T'' at the beginning of your
comments. The most helpful comments reference a specific portion of the
final rule, 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 final rule 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
<a href="http://regulations.gov">regulations.gov</a>, including any personal information you provide. The
agency will also post a report summarizing each substantive verbal
contact received about this final rule.
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 AD 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 AD, 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 AD. Submissions containing CBI should be sent to Narbeh
Mardirosian, Aviation Safety Engineer, FAA, 1600 Stewart Avenue, Suite
410, Westbury, NY 11590; phone: 562-627-5354; email:
<a href="/cdn-cgi/l/email-protection#1678776474737e387b7764727f6479657f77785670777738717960"><span class="__cf_email__" data-cfemail="7719160515121f591a1605131e0518041e16193711161659101801">[email protected]</span></a>. Any commentary that the FAA receives which
is not specifically designated as CBI will be placed in the public
docket for this rulemaking.
Background
The Civil Aviation Authority of Israel (CAAI), which is the
aviation authority for Israel, has issued CAAI AD ISR I-35-26-01-01,
dated January 1, 2026 (CAAI AD ISR I-35-26-01-01) (also referred to as
the MCAI), to correct an unsafe condition on The Boeing Company Model
747-400 series airplanes converted to freighters in accordance with
CAAI Supplemental Type Certificate (STC) SA-151 or validated
equivalent, including FAA STC ST01676SE; or CAAI STC SA-152 or
validated equivalent, including FAA STC ST01706SE. Only FAA STC
ST01676SE and FAA STC ST01706SE are approved for U.S. operators.
The MCAI states that, on one converted airplane, the crew oxygen
bottle flexible hose, part number (P/N) 96431-2, was found ruptured,
and arcing damage was identified on an adjacent cargo loading system
(CLS) wire harness, P/N W9914-301-12, near station (STA) 680. CAAI
determined
[[Page 21374]]
that this condition was caused by chafing of the oxygen hose against
the CLS wire harness.
The FAA is issuing this AD to address chafing, arcing damage, and
insufficient clearance between the crew oxygen bottle flexible hoses
and adjacent wire harnesses. The unsafe condition, if not addressed,
could result in fire and loss of crew oxygen supply due to insufficient
clearance between electrical wiring and the crew oxygen bottle flexible
hose. You may examine the MCAI in the AD docket at <a href="http://regulations.gov">regulations.gov</a>
under Docket No. FAA-2026-3486.
Material Incorporated by Reference Under 1 CFR Part 51
The FAA reviewed Israel Aerospace Industry Ltd., Service Bulletin
366-35-157, dated January 2026. This material specifies procedures for
a detailed inspection of the crew oxygen bottle flexible hoses and
adjacent wire harnesses, near STA 680 for signs of chafing and arcing
damage, and for a minimum clearance of 2 inches between the crew oxygen
bottle flexible hose and the adjacent wire harnesses, and repair, as
applicable.
This material is reasonably available because the interested
parties have access to it through their normal course of business or by
the means identified in the ADDRESSES section.
FAA's Determination
These products have been approved by the civil aviation authority
of another country and are approved for operation in the United States.
Pursuant to the FAA's bilateral agreement with this State of Design
Authority, that authority has notified the FAA of the unsafe condition
described in the MCAI and material referenced above. The FAA is issuing
this AD after determining that the unsafe condition described
previously is likely to exist or develop on other products of the same
type design.
AD Requirements
This AD requires accomplishing the actions specified in the
material already described.
Justification for Immediate Adoption and Determination of the Effective
Date
Section 553(b) of the Administrative Procedure Act (APA) (5 U.S.C.
551 et seq.) authorizes agencies to dispense with notice and comment
procedures for rules when the agency, for ``good cause,'' finds that
those procedures are ``impracticable, unnecessary, or contrary to the
public interest.'' Under this section, an agency, upon finding good
cause, may issue a final rule without providing notice and seeking
comment prior to issuance. Further, section 553(d) of the APA
authorizes agencies to make rules effective in less than thirty days,
upon a finding of good cause.
An unsafe condition exists that requires the immediate adoption of
this AD without providing an opportunity for public comments prior to
adoption. The FAA has found that the risk to the flying public
justifies forgoing notice and comment prior to adoption of this rule
because chafing, arcing damage, and insufficient clearance between the
crew oxygen bottle flexible hoses and adjacent wire harnesses could
result in fire, or loss of crew oxygen supply. Additionally, the
compliance time in this AD is before further flight, which is shorter
than the time necessary for the public to comment and for publication
of the final rule. Accordingly, notice and opportunity for prior public
comment are impracticable and contrary to the public interest pursuant
to 5 U.S.C. 553(b).
In addition, the FAA finds that good cause exists pursuant to 5
U.S.C. 553(d) for making this amendment effective in less than 30 days,
for the same reasons the FAA found good cause to forgo notice and
comment.
Regulatory Flexibility Act
The requirements of the Regulatory Flexibility Act (RFA) do not
apply when an agency finds good cause pursuant to 5 U.S.C. 553 to adopt
a rule without prior notice and comment. Because the FAA has determined
that it has good cause to adopt this rule without prior notice and
comment, RFA analysis is not required.
Costs of Compliance
The FAA estimates that this AD affects 5 airplanes of U.S.
registry. The FAA estimates the following costs to comply with this AD:
Estimated Costs for Required Actions
----------------------------------------------------------------------------------------------------------------
Cost per Cost on U.S.
Labor cost Parts cost product operators
----------------------------------------------------------------------------------------------------------------
1 work-hour x $85 per hour = $85............................. $0 $85 $425
----------------------------------------------------------------------------------------------------------------
The FAA has received no definitive data on which to base the cost
estimates for the repairs specified in this AD.
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, and
(2) Will not affect intrastate aviation in Alaska.
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:
[[Page 21375]]
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:
2026-08-06 The Boeing Company: Amendment 39-23314; Docket No. FAA-
2026-3486; Project Identifier MCAI-2026-00002-T.
(a) Effective Date
This airworthiness directive (AD) is effective May 7, 2026.
(b) Affected ADs
None.
(c) Applicability
This AD applies to The Boeing Company Model 747-400 series
airplanes, certificated in any category, that have been converted to
a freighter configuration in accordance with Supplemental Type
Certificate (STC) ST01676SE or converted to special freighter
configuration in accordance with STC ST01706SE.
(d) Subject
Air Transport Association (ATA) of America Code 35, Oxygen.
(e) Unsafe Condition
This AD was prompted by a report of a ruptured crew oxygen
bottle flexible hose and arcing damage on an adjacent cargo loading
system (CLS) wiring harness near station (STA) 680. The FAA is
issuing this AD to address chafing, arcing damage, and insufficient
clearance between the crew oxygen bottle flexible hoses and adjacent
wire harnesses. The unsafe condition, if not addressed, could result
in fire and loss of crew oxygen supply.
(f) Compliance
Comply with this AD within the compliance times specified,
unless already done.
(g) Required Actions
(1) Before further flight after the effective date of this AD,
do a detailed inspection for chafing and arcing damage of the crew
oxygen bottle flexible hoses and the adjacent wire harnesses, and
for minimum clearance between the crew oxygen bottle flexible hose
and the adjacent wire harnesses, in accordance with the
Accomplishment Instructions of Israel Aerospace Industries Ltd.
Service Bulletin 366-35-157, dated January 2026.
(2) If, during any inspection required by paragraph (g)(1) of
this AD, any chafing or arcing damage is found, or the clearance is
less than 2 inches, before further flight, repair using a method
approved by the Manager, International Validation Branch, FAA; or
the Civil Aviation Authority of Israel (CAAI); or the CAAI's
authorized Designee. If approved by the CAAI Designee, the approval
must include the Designee's authorized signature.
(h) No Reporting Requirement
Although Israel Aerospace Industries Ltd., Service Bulletin 366-
35-157, dated January 2026, specifies to submit certain information
to the manufacturer, this AD does not include that requirement.
(i) Special Flight Permits
A special flight permit may be issued in accordance with 14 CFR
21.197 and 21.199 to operate the airplane to a location where the
corrective actions for insufficient clearance required by this AD
can be performed, provided that there are no signs of wear or
chafing on either the oxygen tubes or electrical wires or harnesses.
(j) Additional AD Provisions
The following provisions also apply to this AD:
(1) Alternative Methods of Compliance (AMOCs): The Manager,
International Validation 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
International Validation Branch, Continued Operational Safety
Branch, send it to the attention of the person identified in
paragraph (k) of this AD and email to: <a href="/cdn-cgi/l/email-protection#26676b69656640474708414950"><span class="__cf_email__" data-cfemail="9edfd3d1dddef8ffffb0f9f1e8">[email protected]</span></a>. Before using
any approved AMOC, notify your appropriate principal inspector, or
lacking a principal inspector, the manager of the responsible Flight
Standards Office.
(2) Contacting the Manufacturer: For any requirement in this AD
to obtain instructions from a manufacturer, the instructions must be
accomplished using a method approved by the Manager, International
Validation Branch, FAA; or the Civil Aviation Authority of Israel
(CAAI); or the CAAI's authorized Designee. If approved by the CAAI
Designee, the approval must include the Designee's authorized
signature.
(k) Additional Information
For more information about this AD, contact Narbeh Mardirosian,
Aviation Safety Engineer, FAA, 1600 Stewart Avenue, Suite 410,
Westbury, NY 11590; phone: 562-627-5354; email:
<a href="/cdn-cgi/l/email-protection#533d322131363b7d3e3221373a213c203a323d133532327d343c25"><span class="__cf_email__" data-cfemail="adc3ccdfcfc8c583c0ccdfc9c4dfc2dec4ccc3edcbcccc83cac2db">[email protected]</span></a>.
(l) Material Incorporated by Reference
(1) The Director of the Federal Register approved the
incorporation by reference (IBR) of the material 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 this AD specifies otherwise.
(i) Israel Aerospace Industries Ltd., Service Bulletin 366-35-
157, dated January 2026.
(ii) [Reserved]
(3) For IAI-Aviation Group material identified in this AD,
contact Israel Aerospace Industries, Ltd., Ben Gurion International
Airport, Israel 7010000; telephone 972-3-9353090; email:
<a href="/cdn-cgi/l/email-protection#10515f5752545b507971793e737f3e797c"><span class="__cf_email__" data-cfemail="f7b6b8b0b5b3bcb79e969ed99498d99e9b">[email protected]</span></a>.
(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 <a href="http://www.archives.gov/federal-register/cfr/ibr-locations">www.archives.gov/federal-register/cfr/ibr-locations</a> or email <a href="/cdn-cgi/l/email-protection#c8aebae6a1a6bbb8adabbca1a7a688a6a9baa9e6afa7be"><span class="__cf_email__" data-cfemail="385e4a1651564b485d5b4c5157567856594a59165f574e">[email protected]</span></a>.
Issued on April 13, 2026.
Steven W. Thompson,
Acting Deputy Director, Compliance & Airworthiness Division, Aircraft
Certification Service.
[FR Doc. 2026-07808 Filed 4-20-26; 4:15 pm]
BILLING CODE 4910-13-P
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