AD 2026-15-06

[Federal Register Volume 91, Number 145 (Thursday, July 30, 2026)]
[Rules and Regulations]
[Pages 47953-47956]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2026-15365]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2026-3477; Project Identifier MCAI-2025-01195-R; 
Amendment 39-23418; AD 2026-15-06]
RIN 2120-AA64


Airworthiness Directives; Bell Textron Canada Limited Helicopters

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule.

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SUMMARY: The FAA is superseding Airworthiness Directive (AD) 2024-02-
55, which applies to certain Bell Textron Canada Limited (BTCL) Model 
505 helicopters. AD 2024-02-55 required initial and recurring 
inspections of the vertical stabilizer top end cap assembly and 
corrective action if a crack is found. Since the FAA issued AD 2024-02-
55, the manufacturer introduced a new one-

[[Page 47954]]

piece vertical stabilizer machined top end cap assembly, which is 
implemented during production, and designed a new replacement for the 
vertical stabilizer machined top end cap assembly currently in service. 
This AD continues to require the inspection requirements of AD 2024-02-
55 and would limit the applicability to exclude certain serial numbered 
BTCL Model 505 helicopters with an improved design vertical stabilizer 
top end cap installed at production. This AD also requires replacing 
the vertical stabilizer top end cap assembly with an improved design 
top end cap assembly, which constitutes a terminating action for the 
recurring detailed visual inspections. The FAA is issuing this AD to 
address the unsafe condition on these products.

DATES: This AD is effective September 3, 2026.
    The Director of the Federal Register approved the incorporation by 
reference of a certain publication listed in this AD as of September 3, 
2026.

ADDRESSES: 
    AD Docket: You may examine the AD docket at regulations.gov under 
Docket No. FAA-2026-3477; 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 
address for Docket Operations is U.S. Department of Transportation, 
Docket Operations, M-30, West Building Ground Floor, Room W12-140, 1200 
New Jersey Avenue SE, Washington, DC 20590.
    Material Incorporated by Reference:
     For Transport Canada material identified in this AD, 
contact Transport Canada, Transport Canada National Aircraft 
Certification, 159 Cleopatra Drive, Nepean, Ontario, K1A 0N5, Canada; 
telephone 888-663-3639; email: [email protected]; internet tc.canada.ca/en/aviation. 
You may find the Transport Canada material on the Transport Canada 
website at wwwapps.tc.gc.ca/Saf-Sec-Sur/2/cawis-swimn/ad_qs1.aspx.
     You may view this material at the FAA, Airworthiness 
Products Section, Operational Safety Branch, 10101 Hillwood Parkway, 
Fort Worth, TX 76177. For information on the availability of this 
material at the FAA, call (817) 222-5110. It is also available at 
regulations.gov under Docket No. FAA-2026-3477.

FOR FURTHER INFORMATION CONTACT: Promita Dey, Aviation Safety Engineer, 
FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590; phone: (913) 
563-8269; email: [email protected].

SUPPLEMENTARY INFORMATION:

Background

    The FAA issued a notice of proposed rulemaking (NPRM) to amend 14 
CFR part 39 to supersede AD 2024-02-55, Amendment 39-22674 (89 FR 
14576, February 28, 2024) (AD 2024-02-55). AD 2024-02-55 applied to 
certain BTCL Model 505 helicopters. AD 2024-02-55 required 
accomplishing initial and recurring inspections of the vertical 
stabilizer top end cap assembly, and if a crack is found, replacement 
of the top end cap. The FAA issued AD 2024-02-55 to address cracking in 
the vertical stabilizer top end cap assembly. This condition, if not 
addressed, could result in the antenna or tuning weight departing from 
the helicopter and impacting and damaging the tail rotor, which could 
result in the loss of directional control of the helicopter.
    The NPRM was published in the Federal Register on April 8, 2026 (91 
FR 17772). The NPRM was prompted by Transport Canada AD CF-2025-32, 
dated July 2, 2025 (Transport Canada AD CF-2025-32) (also referred to 
as the MCAI), issued by Transport Canada, which is the aviation 
authority for Canada. The MCAI states that a new one-piece vertical 
stabilizer machined top end cap assembly, having part number (P/N) SLS-
030-701-149, was implemented into the Bell 505 production line, and a 
new machined top end cap assembly, P/N SLS-704-701-101, was developed 
as a replacement for the top end cap assembly P/N SLS-030-701-125 that 
is currently in service. The MCAI requires repetitive inspections of 
the vertical stabilizer top end cap assembly until the required 
replacement with a new machined top end cap assembly, P/N SLS-704-701-
101, which is considered terminating action for the repetitive 
inspections.
    In the NPRM, the FAA proposed to continue to require the inspection 
requirements of AD 2024-02-55 and proposed to limit the applicability 
to exclude certain serial numbered BTCL Model 505 helicopters with an 
improved design vertical stabilizer top end cap installed at 
production. In the NPRM, the FAA also proposed to require replacing the 
vertical stabilizer top end cap assembly with an improved design top 
end cap assembly, which would constitute a terminating action for the 
recurring detailed visual inspections.
    You may examine the MCAI in the AD docket at regulations.gov under 
Docket No. FAA-2026-3477.

Discussion of Final Airworthiness Directive

Comments

    The FAA received no comments on the NPRM or on the determination of 
the costs.

Conclusion

    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 reviewed the relevant 
data, considered any comments received, and determined that air safety 
requires adopting this AD as proposed. Accordingly, the FAA is issuing 
this AD to address the unsafe condition on these products. Except for 
minor editorial changes, this AD is adopted as proposed in the NPRM. 
None of the changes will increase the economic burden on any operator.

Material Incorporated by Reference Under 1 CFR Part 51

    The FAA reviewed Transport Canada AD CF-2025-32, which specifies 
procedures for accomplishing a one-time detailed visual inspection of 
the vertical stabilizer top end cap assembly for cracking; replacing 
any cracked vertical stabilizer top end cap assembly; repetitively 
inspecting vertical stabilizer top end cap assembly P/N SLS-030-701-
125; and replacing vertical stabilizer top end cap assembly P/N SLS-
030-701-125 with vertical stabilizer top end cap assembly P/N SLS-704-
701-101.
    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.

Differences Between This AD and the MCAI

    Where the material referenced in Transport Canada AD CF-2025-32 
specifies to contact the manufacturer if the drilled holes can no 
longer go beyond the allowable dimensions, this AD requires corrective 
action to be done in accordance with a method approved by the Manager, 
International Validation Branch, FAA; or Transport Canada; or Bell 
Textron Canada Limited Transport Canada Design Approval Organization 
(DAO). If approved by the DAO, the approval must include the DAO-
authorized signature.

[[Page 47955]]

Costs of Compliance

    The FAA estimates that this AD affects 150 helicopters of U.S. 
registry.
    The FAA estimates the following costs to comply with this AD:

                                                 Estimated Costs
----------------------------------------------------------------------------------------------------------------
                                                                                    Cost per       Cost on U.S.
                Action                        Labor cost           Parts cost        product        operators
----------------------------------------------------------------------------------------------------------------
Initial inspection of vertical         2 work-hours x $85 per                $0            $170          $25,500
 stabilizer top end assembly.           hour = $170.
Recurring inspections of vertical      1 work-hour x $85 per                  0              85           12,750
 stabilizer top end assembly.           hour = $85.
Replacement of the vertical            6 work-hours (not                  2,000           2,510          376,500
 stabilizer top end assembly.           including 16 hours to
                                        cure) x $85 per hour =
                                        $510.
----------------------------------------------------------------------------------------------------------------

    The FAA has included all known costs in its cost estimate. 
According to the manufacturer, however, some of the costs of this 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 has determined that 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,
    (2) Will not affect intrastate aviation in Alaska, and
    (3) Will 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 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 2024-02-55, Amendment 39-22674 (89 
FR 14576, February 28, 2024); and
0
b. Adding the following new airworthiness directive:

2026-15-06 Bell Textron Canada Limited: Amendment 39-23418; Docket 
No. FAA-2026-3477; Project Identifier MCAI-2025-01195-R.

(a) Effective Date

    This airworthiness directive (AD) is effective September 3, 
2026.

(b) Affected ADs

    This AD replaces AD 2024-02-55, Amendment 39-22674 (89 FR 14576, 
February 28, 2024).

(c) Applicability

    This AD applies to Bell Textron Canada Limited Model 505 
helicopters, certificated in any category, as identified in 
Transport Canada AD CF-2025-32, dated July 2, 2025 (Transport Canada 
AD CF-2025-32).

(d) Subject

    Joint Aircraft System Component (JASC) Code: 5530, Vertical 
stabilizer structure.

(e) Unsafe Condition

    This AD was prompted by multiple occurrences of the vertical 
stabilizer top end cap assembly being found cracked, with some cases 
including the departure of the navigation/very high frequency omni-
directional range/glide slope antenna and tuning weight from the 
helicopter during flight. The FAA is issuing this AD to address 
cracking in the vertical stabilizer top end cap assembly. The unsafe 
condition, if not addressed, could result in the antenna or tuning 
weight departing from the helicopter and impacting and damaging the 
tail rotor, which could result in the loss of directional control of 
the helicopter.

(f) Compliance

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

(g) Requirements

    Except as specified in paragraphs (h) and (i) of this AD: Comply 
with all required actions and compliance times specified in, and in 
accordance with, Transport Canada AD CF-2025-32.

(h) Exceptions to Transport Canada AD CF-2025-32

    (1) Where Transport Canada AD CF-2025-32 refers to its effective 
date, this AD requires using the effective date of this AD.
    (2) Where Transport Canada AD CF-2025-32 requires compliance in 
terms of hours air time, this AD requires using hours time-in-
service.
    (3) Where the material referenced in Transport Canada AD CF-
2025-32 specifies discarding parts, this AD requires removing those 
parts from service.
    (4) Where the material referenced in Transport Canada AD CF-
2025-32 specifies damage, for the purposes of this AD, damage can be 
indicated by, but not limited to, cracking.
    (5) Where the material referenced in Transport Canada AD CF-
2025-32 specifies to contact the manufacturer if the drilled holes 
can no longer go beyond the allowable dimensions, this AD requires 
corrective action in accordance with a method approved by the 
Manager, International Validation Branch, FAA; or Transport Canada; 
or Bell Textron Canada Limited Transport Canada Design Approval 
Organization (DAO). If approved by the DAO,

[[Page 47956]]

the approval must include the DAO-authorized signature.

(i) No Reporting Requirement

    Although the material referenced in Transport Canada AD CF-2025-
32 specifies submitting certain information to the manufacturer, 
this AD does not include that action.

(j) Credit for Previous Actions

    This paragraph provides credit for the actions required by 
paragraph 1. of Transport Canada AD CF-2025-32, if those actions 
were performed before the effective date of this AD using Bell 
Textron Canada Limited Alert Service Bulletin (ASB) 505-24-38, dated 
January 24, 2024.

(k) 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 (l)(1) 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.

(l) Additional Information

    (1) For more information about this AD, contact Promita Dey, 
Aviation Safety Engineer, FAA, 1600 Stewart Avenue, Suite 410, 
Westbury, NY 11590; phone: (913) 563-8269; email: 
[email protected].
    (2) Material identified in this AD that is not incorporated by 
reference is available at the address specified in paragraph (m)(3) 
of this AD.

(m) Material Incorporated by Reference

    (1) The Director of the Federal Register approved the 
incorporation by reference 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 the AD specifies otherwise.
    (i) Transport Canada AD CF-2025-32, dated July 2, 2025.
    (ii) [Reserved]
    (3) For Transport Canada material identified in this AD, contact 
Transport Canada National Aircraft Certification, 159 Cleopatra 
Drive, Nepean, Ontario, K1A 0N5, Canada; phone 888-663-3639; email 
[email protected]; 
internet tc.canada.ca/en/aviation. You may find the Transport Canada 
material on the Transport Canada website at wwwapps.tc.gc.ca/Saf-Sec-Sur/2/cawis-swimn/ad_qs1.aspx.
    (4) You may view this material at the FAA, Airworthiness 
Products Section, Operational Safety Branch, 10101 Hillwood Parkway, 
Fort Worth, TX 76177. For information on the availability of this 
material at the FAA, call (817) 222-5110.
    (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 July 16, 2026.
Steven W. Thompson,
Acting Deputy Director, Compliance & Airworthiness Division, Aircraft 
Certification Service.
[FR Doc. 2026-15365 Filed 7-29-26; 8:45 am]
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