Airworthiness Directives; Bell Textron Canada Limited Helicopters

[Federal Register Volume 90, Number 118 (Monday, June 23, 2025)]
[Rules and Regulations]
[Pages 26424-26427]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2025-11449]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2025-1111; Project Identifier MCAI-2025-00675-R; 
Amendment 39-23067; AD 2025-13-01]
RIN 2120-AA64


Airworthiness Directives; Bell Textron Canada Limited Helicopters

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 all 
Bell Textron Canada Limited (BTCL) Model 407 and 427 helicopters. This 
AD was prompted by a report that certain expandable blade bolts 
installed on the main rotor blade may not have received the correct 
heat treatment, which could

[[Page 26425]]

result in stress corrosion cracking of the expandable blade bolts. This 
AD requires removing the expandable blade bolts from service and 
replacing them with a part eligible for installation. This AD also 
prohibits the installation of an affected expandable blade bolt on any 
helicopter. The FAA is issuing this AD to address the unsafe condition 
on these products.

DATES: This AD is effective July 8, 2025.
    The FAA must receive comments on this AD by August 7, 2025.

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-2025-1111; 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: Adam Hein, Aviation Safety Engineer, 
FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590; phone: (316) 
946-4116; 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 to an address listed under 
the ADDRESSES section. Include ``Docket No. FAA-2025-1111; Project 
Identifier MCAI-2025-00675-R'' 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 Adam 
Hein, 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

    Transport Canada, which is the aviation authority for Canada, has 
issued Transport Canada AD CF-2025-21, dated April 22, 2025 (referred 
to as ``the MCAI''), to address an unsafe condition on BTCL Model 407 
and 427 helicopters. The MCAI states that part number 406-310-103-103 
expandable blade bolts with certain serial numbers may not have 
received the correct heat treatment, which could result in stress 
corrosion cracking of the expandable blade bolts installed on the main 
rotor blade. The MCAI requires replacing the expandable blade bolts 
with serviceable expandable blade bolts. The MCAI also prohibits 
installing the affected expandable blade bolts on BTCL Model 407 and 
427 helicopters.
    The FAA is issuing this AD to address the unsafe condition on these 
products. The unsafe condition, if not addressed, could result in 
failure of the main rotor blade assembly, detachment of the main rotor 
blade, and consequent loss of control of the helicopter.
    You may examine the MCAI in the AD docket at regulations.gov under 
Docket No. FAA-2025-1111.

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.

Requirements of This AD

    This AD requires removing the expandable blade bolts from service 
and installing an expandable blade bolt that does not have an affected 
serial number. This AD also prohibits installing an affected expandable 
blade bolt on any helicopter.

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 expandable blade bolts are critical components that, if 
improperly heat-treated, could be subject to stress corrosion cracking. 
Stress corrosion cracking of the expandable blade bolts could result in 
the failure of the main rotor blade assembly, detachment of the main 
rotor blade, and consequent loss of control of the helicopter. This 
failure could happen at any time without any previous indications. 
Additionally, the initial actions required by this AD must be 
accomplished within 30 hours time-in-service or 30 days, whichever 
occurs first, 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

[[Page 26426]]

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 946 helicopters of U.S. 
registry. There are 20 expandable blade bolts identified as having this 
unsafe condition, and up to 4 expandable blade bolts could be installed 
per helicopter. The FAA has no way of knowing the number of helicopters 
of U.S. registry that may have an affected expandable blade bolt 
installed. The estimated cost on U.S. operators reflects the costs 
based on the number of expandable blade bolts that need to be replaced.
    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
----------------------------------------------------------------------------------------------------------------
Replace expandable blade bolt (up  2 work-hours x $85   $5,271 per bolt....  Up to $21,764......        $108,820
 to four bolts per helicopter).     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:
    (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 adding the following new airworthiness 
directive:

2025-13-01 Bell Textron Canada Limited: Amendment 39-23067; Docket 
No. FAA-2025-1111; Project Identifier MCAI-2025-00675-R.

(a) Effective Date

    This airworthiness directive (AD) is effective July 8, 2025.

(b) Affected ADs

    None.

(c) Applicability

    This AD applies to Bell Textron Canada Limited Model 407 and 427 
helicopters, certificated in any category.

(d) Subject

    Joint Aircraft System Component (JASC) Code 6210, Main Rotor 
Blades.

(e) Unsafe Condition

    This AD was prompted by a report that certain expandable blade 
bolts installed on the main rotor blade may not have received the 
correct heat treatment, which could lead to stress corrosion 
cracking of the expandable blade bolts. The FAA is issuing this AD 
to prevent stress corrosion cracking of the expandable blade bolts 
installed on the main rotor blade. The unsafe condition, if not 
addressed, could result in failure of the main rotor blade assembly, 
detachment of the main rotor blade, and consequent loss of control 
of the helicopter.

(f) Compliance

    Comply with this AD within the compliance times specified, 
unless already done.

(g) Required Actions

    Within 30 hours time-in-service or 30 days, whichever occurs 
first after the effective date of this AD, remove from service each 
affected part and replace with a part eligible for installation.

(h) Parts Installation Prohibition

    As of the effective date of this AD, do not install an affected 
part as defined in this AD on any helicopter.

(i) Definitions

    For the purpose of this AD, the following definitions apply:
    (1) An ``affected part'' is an expandable blade bolt having part 
number (P/N) 406-310-103-103 and a serial number SLFS9386 through 
SLFS9405 inclusive.
    (2) A ``part eligible for installation'' is an expandable blade 
bolt having P/N 406-310-103-103 that does not have a serial number 
listed in paragraph (i)(1) of this AD.

(j) Alternative Methods of Compliance (AMOCs)

    (1) 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 (k) of 
this AD and email to: [email protected].
    (2) 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.

[[Page 26427]]

(k) Additional Information

    For more information about this AD, contact Adam Hein, Aviation 
Safety Engineer, FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY 
11590; phone: (316) 946-4116; email: [email protected].

(l) Material Incorporated by Reference

    None.

    Issued on June 17, 2025.
Steven W. Thompson,
Acting Deputy Director, Compliance & Airworthiness Division, Aircraft 
Certification Service.
[FR Doc. 2025-11449 Filed 6-18-25; 11:15 am]
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