[Federal Register Volume 90, Number 195 (Friday, October 10, 2025)]
[Rules and Regulations]
[Pages 48219-48221]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2025-19532]



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Rules and Regulations
                                                Federal Register
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This section of the FEDERAL REGISTER contains regulatory documents 
having general applicability and legal effect, most of which are keyed 
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under 50 titles pursuant to 44 U.S.C. 1510.

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Federal Register / Vol. 90, No. 195 / Friday, October 10, 2025 / 
Rules and Regulations

[[Page 48219]]



DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2025-3433; Project Identifier MCAI-2025-01302-Q; 
Amendment 39-23173; AD 2025-21-01]
RIN 2120-AA64


Airworthiness Directives; Cameron Balloons Ltd. Fuel Cylinders

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule; request for comments.

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

SUMMARY: The FAA is superseding Airworthiness Directive (AD) 2025-11-
10, which applied to Cameron Balloons Ltd. (Cameron) fuel cylinders 
fitted with certain pressure relief valve (PRV) adaptors on hot air 
balloons. AD 2025-11-10 required repetitively visually checking the PRV 
adaptor for cracks and removing any fuel cylinder with a cracked PRV 
adaptor from service. Since the FAA issued AD 2025-11-10, a new 
replacement part was introduced into service. This AD retains the 
repetitive check and removal requirements of AD 2025-11-10 and also 
requires replacement of the PRV adaptor as terminating action for the 
repetitive checks. The FAA is issuing this AD to address the unsafe 
condition on these products.

DATES: This AD is effective October 27, 2025.
    The FAA must receive comments on this AD by November 24, 2025.

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. FAA-2025-3433; 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.

FOR FURTHER INFORMATION CONTACT: George Weir, Aviation Safety Engineer, 
FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590; phone: (817) 
222-4045; email: [email protected].

SUPPLEMENTARY INFORMATION:

Comments Invited

    The FAA invites you to send any written data, views, or arguments 
about this final rule. Send your comments using a method listed under 
the ADDRESSES section. Include ``Docket No. FAA-2025-3433; Project 
Identifier MCAI-2025-01302-Q'' 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 George 
Weir, Aviation Safety Engineer, FAA, 1600 Stewart Avenue, Suite 410, 
Westbury, NY 11590. 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 FAA issued AD 2025-11-10, Amendment 39-23056 (90 FR 23269, June 
2, 2025) (AD 2025-11-10), to correct an unsafe condition on hot air 
balloons with Cameron fuel cylinders fitted with PRV adaptor part 
number (P/N) CB8426. AD 2025-11-10 was prompted by an MCAI originated 
by the Civil Aviation Authority (CAA), which is the airworthiness 
authority for the United Kingdom (UK). The UK CAA issued Emergency AD 
G-2025-0001R1-E, dated April 11, 2025, (CAA UK Emergency AD G-2025-
0001R1-E) to correct an unsafe condition identified as cracks on the 
upper hex portion of PRV adaptors. AD 2025-11-10 required repetitively 
visually checking the fuel cylinder PRV adaptor for cracks, reporting 
any findings of a crack, and removing any fuel cylinder with a cracked 
PRV adaptor from service. A cracked PRV adaptor could lead to 
uncontrolled leakage of liquefied petroleum gas (LPG), which could 
result in an in-flight fire and consequent emergency landing. The FAA 
issued AD 2025-11-10 to address the unsafe condition on these products.

Actions Since AD 2025-11-10 Was Issued

    Since the FAA issued AD 2025-11-10, the UK CAA superseded CAA UK 
Emergency AD G-2025-0001R1-E and issued CAA UK Emergency AD G-2025-
0004-E, dated August 1, 2025 (CAA UK Emergency AD G-2025-0004-E) (also 
referred to as the MCAI). The MCAI states that after an examination of 
10 additional failed components and subsequent metallurgical analysis, 
a

[[Page 48220]]

new replacement PRV adaptor was introduced into service to better 
address the unsafe condition. The MCAI requires repetitively visually 
checking the fuel cylinder PRV adaptor for cracks, removal from service 
of any fuel cylinder with a cracked PRV adaptor, and replacement of the 
PRV adaptor as terminating action for the repetitive checks. This 
condition, if not addressed, could lead to uncontrolled leakage of LPG, 
which could result in an in-flight fire and consequent emergency 
landing.
    You may examine the MCAI in the AD docket at regulations.gov under 
Docket No. FAA-2025-3433.

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 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 retains the repetitive check and removal requirements of AD 
2025-11-10 and also requires replacement of the PRV adaptor as 
terminating action for the repetitive checks. The owner/operator 
(pilot) holding at least a private pilot certificate may perform the 
visual check and must enter compliance with the applicable paragraph(s) 
of the AD into the balloon maintenance records in accordance with 14 
CFR 43.9(a) and 91.417(a)(2)(v). The pilot may perform this action 
because it only involves visually checking each PRV adaptor for cracks. 
This action could be performed equally well by a pilot or a mechanic. 
This is an exception to the FAA's standard maintenance regulations.

Differences Between This AD and the MCAI

    The MCAI applies to hot air balloons and certain airships. This AD 
only applies to hot air balloons because the airships identified in the 
MCAI do not have an FAA type certificate.
    Although the MCAI specifies that if any fuel cylinder is found with 
a cracked PRV adaptor, it must be emptied of fuel prior to being 
removed from service, this AD does not require that action. While that 
action is encouraged for the general safety related to the leakage of 
LPG, it is not required to address the unsafe condition identified in 
this AD.

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 an LPG leak on the fuel cylinder could result in an in-flight 
fire or explosion, damaging the hot air balloon and leading to a forced 
emergency landing, which could injure balloon occupants and persons on 
the ground. Additionally, the compliance time in this AD 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 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 2,000 fuel cylinders 
installed on hot air balloons worldwide. The FAA estimates 100 hot air 
balloons of U.S. Registry may have an affected fuel cylinder installed.
    The FAA estimates the following costs to comply with this AD:

                                                 Estimated Costs
----------------------------------------------------------------------------------------------------------------
                                                                                                Cost on U.S.
              Action                    Labor cost        Parts cost    Cost per product          operators
----------------------------------------------------------------------------------------------------------------
Visually check fuel cylinder PRV   1 work-hour x $85              $0  $85 (per visual       $8,500 (per visual
 adaptor.                           per hour = $85 (per                check).               check).
                                    visual check).
Replace fuel cylinder PRV adaptor  2 work-hours x $85             29  199.................  19,900.
                                    per hour = $170.
----------------------------------------------------------------------------------------------------------------

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:

[[Page 48221]]

    (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:

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:
0
a. Removing Airworthiness Directive 2025-11-10, Amendment 39-23056 (90 
FR 23269, June 2, 2025); and
0
b. Adding the following new airworthiness directive:

2025-21-01 Cameron Balloons Ltd.: Amendment 39-23173; Docket No. 
FAA-2025-3433; Project Identifier MCAI-2025-01302-Q.

(a) Effective Date

    This airworthiness directive (AD) is effective October 27, 2025.

(b) Affected ADs

    This AD replaces AD 2025-11-10, Amendment 39-23056 (90 FR 23269, 
June 2, 2025) (AD 2025-11-10).

(c) Applicability

    (1) This AD applies to all hot air balloons, certificated in any 
category, with a fuel cylinder installed that is fitted with Cameron 
Balloons Ltd. pressure relief valve (PRV) adaptor part number (P/N) 
CB8426.
    Note 1 to paragraph (c)(1): Cameron Balloons Alert Service 
Bulletin No. 36, Revision 2, dated July 3, 2025, provides 
information related to this AD, including fuel cylinders that may be 
fitted with PRV adaptor P/N CB8426.
    (2) These fuel cylinders are installed on hot air balloon models 
including, but not limited to, those of the design approval holders 
identified in paragraphs (c)(2)(i) through (viii) of this AD.
    (i) Adams Aerostats LLC.
    (ii) Aerostar International Inc.
    (iii) Ballonbau W[ouml]rner GmbH.
    (iv) Cameron Balloons Ltd.
    (v) Eagle Balloons Corp.
    (vi) JR Aerosports, Ltd.
    (vii) Kub[iacute][ccaron]ek Factory s.r.o. (formerly 
Bal[oacute]ny Kub[iacute][ccaron]ek spol. s.r.o.).
    (viii) Lindstrand Balloons Ltd.

(d) Subject

    Joint Aircraft System Component (JASC) Code 2800, Aircraft Fuel 
System.

(e) Unsafe Condition

    This AD was prompted by cracks on the upper hex portion of PRV 
adaptors installed on certain Cameron Balloons Ltd. fuel cylinders. 
The FAA is issuing this AD to address failure of a PRV adaptor. This 
condition, if not addressed, could lead to uncontrolled leakage of 
liquefied petroleum gas, which could result in an in-flight fire and 
consequent emergency landing.

(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 
and thereafter before each flight, visually check the fuel cylinder 
PRV adaptor for any cracks.
    (2) The owner/operator (pilot) holding at least a private pilot 
certificate may perform the visual checks required by paragraph 
(g)(1) of this AD and must enter compliance with the applicable 
paragraph of this AD into the balloon maintenance records in 
accordance with 14 CFR 43.9(a) and 91.417(a)(2)(v). The record must 
be maintained as required by 14 CFR 91.417, 121.380, or 135.439.
    (3) Replace the fuel cylinder PRV adaptor with a fuel cylinder 
PRV adaptor having P/N CB7922 at whichever compliance time in 
paragraph (g)(3)(i) or (ii) occurs first.
    (i) Before further flight if any crack is found during any 
visual check required by paragraph (g)(1) of this AD.
    (ii) At or before the next scheduled periodic PRV inspection.
    (4) The replacement required by paragraph (g)(3) of this AD 
terminates the repetitive visual check requirement of paragraph 
(g)(1) of this AD.

(h) Special Flight Permits

    Special flight permits are prohibited.

(i) 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 local Flight 
Standards District Office, as appropriate. If sending information 
directly to the manager of the International Validation Branch, send 
it to the attention of the person identified in paragraph (j)(1) 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 local flight standards district 
office/certificate holding district office.

(j) Additional Information

    (1) For more information about this AD, contact George Weir, 
Aviation Safety Engineer, FAA, 1600 Stewart Avenue, Suite 410, 
Westbury, NY 11590; phone: (817) 222-4045; email: 
[email protected].
    (2) For material identified in this AD that is not incorporated 
by reference, contact Cameron Balloons Ltd., St John Street, 
Bedminster, Bristol, BS3 4NH, United Kingdom; phone: +44 0 117 
9637216; email: cameronballoons.co.uk">technical@cameronballoons.co.uk; website: 
cameronballoons.co.uk.

(k) Material Incorporated by Reference

    None.

    Issued on October 7, 2025.
Steven W. Thompson,
Acting Deputy Director, Compliance & Airworthiness Division, Aircraft 
Certification Service.
[FR Doc. 2025-19532 Filed 10-9-25; 8:45 am]
BILLING CODE 4910-13-P