Airworthiness Directives; The Boeing Company Airplanes

[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 [www.gpo.gov]
[FR Doc No: 2026-07808]



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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.

-----------------------------------------------------------------------

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 regulations.gov. 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 regulations.gov 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: 
[email protected].
    <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 regulations.gov 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: [email protected].

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 
regulations.gov, 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: 
[email protected]. 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 regulations.gov 
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: [email protected]. 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: 
[email protected].

(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: 
[email protected].
    (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 [email protected].

    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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