DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2022-0807; Project Identifier AD-2022-00214-R;
Amendment 39-22188; AD 2022-20-04]
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) 2021-26-
08, which applied to certain Bell Textron Canada Limited Model 206,
206A, 206A-1, 206B, 206B-1, 206L, 206L-1, 206L-3, and 206L-4
helicopters. AD 2021-26-08 required removing certain nuts from service;
installing newly designed nuts; applying a specific torque, and a
torque stripe to each newly installed nut; after the installation of
each newly designed nut, inspecting the torque; and depending on the
inspection results, either applying a torque stripe, or performing
further inspections and removing certain parts from service. AD 2021-
26-08 also prohibited installing any affected nut on any tail rotor
drive shaft (TRDS) disc pack (Thomas) coupling. Since the FAA issued AD
2021-26-08, the FAA determined certain torque values and part numbers
(P/Ns) need to be revised. This AD was prompted by reports of cracked
or missing nuts installed on the TRDS Thomas couplings and the need to
revise certain torque values and P/Ns in AD 2021-26-08. This AD
requires removing certain nuts from service; installing newly designed
nuts; applying torque and a torque stripe; and additional corrective
actions if necessary. This AD also prohibits installing any affected
nut on any TRDS Thomas coupling, as specified in a Transport Canada AD,
which is incorporated by reference. The FAA is issuing this AD to
address the unsafe condition on these products.
DATES: This AD is effective December 23, 2022.
The Director of the Federal Register approved the incorporation by
reference of certain publications listed in this AD as of December 23,
2022.
ADDRESSES: For Transport Canada material incorporated by reference
(IBR) in this final rule, contact Transport Canada, Transport Canada
National Aircraft Certification, 159 Cleopatra Drive, Nepean, Ontario,
K1A 0N5, CANADA; telephone 888-663-3639; email
TC.AirworthinessDirectives-Consignesdenavigabilite.TC@tc.gc.ca;
internet tc.canada.ca/en/aviation. You may find the Transport Canada
material on the Transport Canada website at tc.canada.ca/en/aviation.
For Air Comm Corporation service information identified in this final
rule, contact Air Comm Corporation, 1575 West 124th Ave. #210,
Westminster, CO 80234; telephone (303) 440-4075; email
service@aircommcorp.com; or at aircommcorp.com. For Bell service
information identified in this final rule, contact Bell Textron Canada
Limited, 12,800 Rue de l'Avenir, Mirabel, Quebec J7J 1R4, Canada;
telephone 1-450-437-2862 or 1-800-363-8023; fax 1-450-433-0272; email
productsupport@bellflight.com; or at bellflight.com/support/contact-support.
You may view this material at the FAA, Office of the Regional
Counsel, Southwest Region, 10101 Hillwood Pkwy., Room 6N-321, Fort
Worth, TX 76177. For information on the availability of this material
at the FAA, call (817) 222-5110. Service information that is IBRed is
also available in the AD docket at regulations.gov by searching for and
locating Docket No. FAA-2022-0807.
Examining the AD Docket
You may examine the AD docket at regulations.gov by searching for
and locating Docket No. FAA-2022-0807; 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 Transport
Canada AD, 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.
FOR FURTHER INFORMATION CONTACT: Matt Fuller, AD Program Manager,
General Aviation & Rotorcraft Unit, Airworthiness Products Section,
Operational Safety Branch, FAA, 10101 Hillwood Pkwy., Fort Worth, TX
76177; telephone (817) 222-5110; email matthew.fuller@faa.gov.
SUPPLEMENTARY INFORMATION:
Background
The FAA issued a notice of proposed rulemaking (NPRM) to amend 14
CFR part 39 to supersede AD 2021-26-08, Amendment 39-21867 (86 FR
72833, December 23, 2021) (AD 2021-26-08). AD 2021-26-08 applied to
Bell Textron Canada Limited Model 206, 206A, 206A-1, 206B, 206B-1,
206L, 206L-1, 206L-3, and 206L-4 helicopters, with nut P/N MS21042L4 or
P/N MS21042L5 installed on the TRDS Thomas couplings. AD 2021-26-08
required removing certain nuts from service, installing newly designed
nuts, and applying a specific torque and a torque stripe to each newly
installed nut. AD 2021-26-08 also required, after the installation of
each newly designed nut, inspecting the torque and, depending on the
inspection results, either applying a torque stripe or performing
further inspections and removing certain parts from service. Finally,
AD 2021-26-08 prohibited installing any affected nut on any TRDS Thomas
coupling. The FAA issued AD 2021-26-08 to prevent failure or loss of a
nut on any TRDS Thomas coupling.
AD 2021-26-08 was prompted by Transport Canada AD CF-2020-15, dated
May 13, 2020 (Transport Canada AD CF-2020-15). Transport Canada, which
is the aviation authority for Canada, issued Transport Canada AD CF-
2020-15 to correct an unsafe condition for Bell Textron Canada Limited
Model 206, 206A, 206A-1, 206B, 206B-1, 206L, 206L-1, 206L-3, and 206L-4
helicopters, all serial numbers. Transport Canada AD CF-2020-15
specifies for certain model helicopters, newly designed nuts cannot be
installed because Supplemental Type Certificate (STC) SH2750NM and
Transport Canada STC SH99-202 install a pulley at the Thomas coupling
location causing insufficient clearance. Transport Canada advises, for
certain model helicopters with STC SH2750NM or Transport Canada STC SH99-202
installed, different part-numbered nuts may be installed and are now
required to be replaced with a new part-numbered nut that is not
vulnerable to the unsafe condition.
The NPRM published in the Federal Register on June 30, 2022 (87 FR
39015). The NPRM was prompted by reports of cracked or missing nuts
installed on the TRDS Thomas couplings. The NPRM was also prompted by
the determination that certain P/Ns and certain torque values in
paragraph (g) of AD 2021-26-08 need to be revised. Furthermore, the FAA
advises that the 50-70 in lb torque values are only applicable to
certain bolts and nuts, and a 150-180 in lb torque value is required
for other bolts and nuts that are required to be installed by this AD.
The FAA also advises that certain part-numbered nuts that are required
to be installed according to AD 2021-26-08 need to be removed from
service and replaced due to a certain pulley configuration. The NPRM
proposed to require removing certain nuts from service; installing
newly designed nuts; applying torque and a torque stripe; and
additional corrective actions if necessary. The NPRM also proposed to
prohibit installing any affected nut on any TRDS Thomas coupling, as
specified in Transport Canada AD CF-2020-15.
The FAA is issuing this AD to prevent failure or loss of a nut on
the TRDS Thomas couplings, which if not addressed could result in loss
of the tail rotor and subsequent loss of control of the helicopter. See
Transport Canada AD CF-2020-15 for additional background information.
Discussion of Final Airworthiness Directive
Comments
The FAA received no comments on the NPRM or on the determination of
the costs.
Conclusion
These helicopters have been approved by the aviation authority of
Canada and are approved for operation in the United States. Pursuant to
the FAA's bilateral agreement with Canada, Transport Canada, its
technical representative, has notified the FAA of the unsafe condition
described in its AD. The FAA reviewed the relevant data, considered the
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 helicopters. This AD is adopted as
proposed in the NPRM, except the FAA has removed the note to the
applicability paragraph and updated the identification of Model 206A-1
helicopters in the applicability paragraph to Model 206A-1 (OH-58A)
helicopters to match the FAA type certificate data sheet. None of these
changes will increase the economic burden on any operator.
Related Service Information Under 1 CFR Part 51
Transport Canada AD CF-2020-15 requires the replacement of certain
part-numbered nuts with newly designed nuts at each TRDS Thomas
coupling and prohibits installing any affected nut on any TRDS Thomas
coupling. The replacement includes applying torque, and a torque
stripe.
The FAA reviewed Air Comm Corporation Service Bulletin SB 206EC-
092619, Revision NC, dated September 26, 2019, which also specifies
procedures for replacing the affected nuts with the newly designed
corrosion-resistant nuts, but explains that affected helicopters
equipped with Air Comm Corporation air conditioning systems installed
under STC SH2750NM use the affected nut to attach a pulley onto the
TRDS, which causes clearance issues for the nuts to be installed at the
coupling. Therefore, this service bulletin specifies replacing the nut
with a lower profile nut.
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.
Other Related Service Information
The FAA also reviewed Bell Alert Service Bulletin (ASB) 206-19-136,
dated August 27, 2019, for FAA-certificated Model 206, 206A-series, and
206B-series helicopters, and non FAA-certificated Model TH-67
helicopters; and Bell ASB 206L-19-181, dated August 27, 2019, and
Revision A, dated August 29, 2019, for Model 206L, 206L-1, 206L-3, and
206L-4 helicopters. This service information specifies procedures for
replacing the affected nuts with the newly designed corrosion-resistant
nuts. Revision A of Bell ASB 206L-19-181 corrects a typographical
error.
Additionally, the FAA reviewed Bell Service Instruction BHT-206-SI-
2052, Revision 1, dated October 14, 2010. This service information
specifies procedures to upgrade Model 206L-1 and 206L-3 helicopters to
allow operations at an increased internal gross weight.
Differences Between This AD and Transport Canada AD CF-2020-15
Transport Canada AD CF-2020-15 requires compliance with certain
actions within 600 hours air time or within the next 24 months,
whichever occurs first, whereas this AD requires compliance within 600
hours time-in-service only. Service information referenced in Transport
Canada AD CF-2020-15 specifies if any P/N MS21042L4 nuts are found
loose or damaged, reporting the location and providing the information
to Bell, whereas this AD requires if any P/N MS21042L4 nuts are found
loose or damaged, inspecting each TRDS Thomas coupling, including each
bolt, nut, and washer, for any elongated holes, fretting on the
fasteners, and damaged fasteners, and depending on the results of the
inspection, removing from service each affected part and replacing it
with an airworthy part.
Costs of Compliance
The FAA estimates that this AD affects 1,359 helicopters of U.S.
Registry. Labor rates are estimated at $85 per work-hour. Based on
these numbers, the FAA estimates the following costs to comply with
this AD.
Replacing each affected nut with the newly designed nut and
applying torque and a torque stripe takes about 4 work-hours, and parts
cost about $75 for an estimated cost of $415 per nut replacement and
$563,985 per nut replacement for the U.S. fleet.
In addition, the costs of the actions that are part of the required
replacement are as follows:
If required, due to loose or damaged nuts found, inspecting each
TRDS Thomas coupling, and each bolt, nut, and washer for elongated
holes and fretting on the fasteners takes about 0.5 work-hour for an
estimated cost of $43 per inspection.
If required, replacing each TRDS Thomas coupling takes about 4
work-hours, and parts cost about $4,000 for an estimated cost of $4,340
per TRDS Thomas coupling replacement.
If required, replacing a bolt or washer takes a minimal amount of
time and parts cost a nominal amount.
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,
(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
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]
2. The FAA amends Sec. 39.13 by:
a. Removing Airworthiness Directive (AD) 2021-26-08, Amendment 39-21867
(86 FR 72833, December 23, 2021); and
b. Adding the following new AD:
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