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Published 2021-09-27 · Federal Register document 2021-20829

Airworthiness Directives; Bell Textron Canada Limited (Type Certificate Previously Held by Bell Helicopter Textron Canada Limited) Helicopters

Publication summary

The FAA is adopting a new airworthiness directive (AD) for certain Bell Textron Canada Limited (Bell) Model 429 helicopters. This AD was prompted by reports of tail rotor gearbox assemblies found loose on the gearbox support. This AD requires repetitive torque checks of the tail rotor gearbox attachment hardware, and corrective action if necessary. The FAA is issuing this AD to address the unsafe condition on these products.

Why this record is shown

Source: Federal Register annual FAA metadata. Acquired 2026-09-03T22:24:08.106391+00:00. The title, summary and date are source facts.

Source revision
federal_register_ad_metadata_2021-9c919420683447c6
Source row
results[348]
Raw source SHA-256
9c919420683447c683ad0c877cb886e341c11862be32b47c536a001b1d76dcb5

Final-rule publication

Recorded publication clauses

AD identifier printed in this edition
2021-18-16
Effective date printed in this edition
2021-11-01
Read 12 complete recorded clauses
Effective Date
(a) Effective Date

    This airworthiness directive (AD) is effective November 1, 2021.

Exact source excerpt. Text positions 10281–10371, end exclusive, in the original decoded publication. SHA-256: 1298cbc4656f39d73a03382b3e00ea0c36527ec17d50af2aafe96f027fb999bc

Affected ADs
(b) Affected ADs

    None.

Exact source excerpt. Text positions 10371–10400, end exclusive, in the original decoded publication. SHA-256: 871a4afc60ceeae06e8010585055188633d616078500c45937092bfe892239c0

Applicability wording · Applicability
(c) Applicability

    This AD applies to Bell Textron Canada Limited (type certificate 
previously held by Bell Helicopter Textron Canada Limited) Model 429 
helicopters, certificated in any category, serial numbers 57001 and 
subsequent.

Exact source excerpt. Text positions 10400–10641, end exclusive, in the original decoded publication. SHA-256: 7fa0b58123922dab5afd17bcc3370c697789bc5ba305664f0044dfdad0462ee6

Subject
(d) Subject

    Joint Aircraft Service Component (JASC) Code: 6500, Tail Rotor 
Drive System; and 6520, Tail Rotor Gearbox.

Exact source excerpt. Text positions 10641–10767, end exclusive, in the original decoded publication. SHA-256: 6ed0b5dc72613c328de550f9122ba8f80247ce785e8b8d7124ac5bab944bbf77

Unsafe Condition
(e) Unsafe Condition

    This AD was prompted by reports of tail rotor gearbox assemblies 
found loose on the gearbox support. The FAA is issuing this AD 
address tail rotor gearbox assemblies found loose on the gearbox 
support. The unsafe condition, if not addressed, could result in 
structural damage and possible loss of control of the helicopter.

Exact source excerpt. Text positions 10767–11122, end exclusive, in the original decoded publication. SHA-256: 6dc8d9485b0df20e68b455677b7a519d718ed45fe7dab7af5223818e671194af

Compliance
(f) Compliance

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

Exact source excerpt. Text positions 11122–11224, end exclusive, in the original decoded publication. SHA-256: 00fbfa31932483f627d0ce0a11cbd2e35e15d9231842b91ac85623ce533912d3

Required Actions
(g) Required Actions

    Within 12 months after the effective date of this AD; or at the 
next scheduled 200-hours time-in-service (TIS) or 12-month 
inspection, whichever occurs first, do a torque check of the tail 
rotor gearbox attachment hardware, in accordance with the 
Accomplishment Instructions, paragraph 2., of Bell Alert Service 
Bulletin 429-18-41, dated July 24, 2018. Repeat the torque check 
thereafter at intervals not to exceed 200 hours TIS or 12 months, 
whichever occurs first.

Exact source excerpt. Text positions 11224–11725, end exclusive, in the original decoded publication. SHA-256: b676db050a52b4c2cd73a25b7c33e0301a851ac2b3d8b5631c7b5f7036433242

Corrective Actions
(h) Corrective Actions

    If, during any torque check required by paragraph (g) of this 
AD, any tail rotor gearbox attachment moves during any torque check, 
repeat the torque check specified in paragraph (g) of this AD at 
intervals no less than 10 hours TIS and not to exceed 25 hours TIS 
until the torque stabilizes on all the nuts. Stabilization has 
occurred when, at the next torque check, the value has remained 
within the specified acceptable limits (160 to 200 inch-pounds (in-
lbs) or 19 to 22 newton meters (Nms), inclusive), preventing 
movement of the gearbox housing. After the torque stabilizes on all 
the nuts, the repetitive torque checks specified in paragraph (g) of 
this AD are still required.

Exact source excerpt. Text positions 11725–12447, end exclusive, in the original decoded publication. SHA-256: 1818d394d3ba306c9f83842d83419c17fa8cb910487178af41edf44e83d6b199

Credit for Previous Actions
(i) Credit for Previous Actions

    This paragraph provides credit for the initial torque check 
required by paragraph (g) of this AD, if that action was done before 
the effective date of this AD as required by paragraph (f)(2) of AD 
2018-16-51, Amendment 39-19421 (83 FR 53171, October 22, 2018).

Exact source excerpt. Text positions 12447–12749, end exclusive, in the original decoded publication. SHA-256: 19942c658369ec3c70bfb4f648af072282b7a08d0a622f68ca3163bac4deaf1a

Alternative Methods of Compliance (AMOCs)
(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

[[Page 53205]]

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)(1) of 
this AD. Information may be emailed 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.

Exact source excerpt. Text positions 12749–13558, end exclusive, in the original decoded publication. SHA-256: bbec0686e62a696dd88dfa671a495d68b60bbb07fa82e8db88bf95b7add3799c

Related Information
(k) Related Information

    (1) For more information about this AD, contact Darren Gassetto, 
Aerospace Engineer, COS Program Management Section, FAA, Operational 
Safety Branch, Compliance & Airworthiness Division, 1600 Stewart 
Avenue, Suite 410, Westbury, NY 11590; telephone 516-228-7323; email 
[email protected].
    (2) The subject of this AD is addressed in Transport Canada AD 
CF-2018-35, dated December 19, 2018. You may view the Transport 
Canada AD at https://www.regulations.gov in Docket No. FAA-2021-
0513.

Exact source excerpt. Text positions 13558–14083, end exclusive, in the original decoded publication. SHA-256: 49a70e5b01fa386e50dfefe0ceacdf6cd2e7be675300d8099d750090802740db

Material Incorporated by Reference
(l) Material Incorporated by Reference

    (1) The Director of the Federal Register approved the 
incorporation by reference of the service information listed in this 
paragraph under 5 U.S.C. 552(a) and 1 CFR part 51.
    (2) You must use this service information as applicable to do 
the actions required by this AD, unless the AD specifies otherwise.
    (i) Bell Alert Service Bulletin 429-18-41, dated July 24, 2018.
    (ii) [Reserved]
    (3) For service information identified in this AD, 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 [email protected]; or at https://www.bellflight.com/support/contact-support.
    (4) You may view this service information 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.
    (5) You may view this service information that is incorporated 
by reference at the National Archives and Records Administration 
(NARA). For information on the availability of this material at 
NARA, email: [email protected], or go to: https://www.archives.gov/federal-register/cfr/ibr-locations.html.

Exact source excerpt. Text positions 14083–15385, end exclusive, in the original decoded publication. SHA-256: 65695c78922294aaec6e97f4c355449f53b43ef5bc4bedce1be0da5372179555

No replacement link has been established from this edition. The complete historical rule chain and current legal effect remain unknown.

Find all recorded historical references to AD 2021-18-16 · 0 printed reference observations in this pinned collection.

These are observations from one dated publication. Current legal status is unknown; aircraft applicability, installed configuration, compliance and burden require separate evidence. Missing or unparsed conditions remain unknown.

Why these observations are shown

They were extracted offline from the same immutable official HTML source as the complete recorded text. The dated source wording, original text coordinates and exact quote digests are retained. PDF/text agreement and current regulatory effect have not been qualified.

Observation revision: whole-ad-publication-clause-observations-1.0.1. Text SHA-256: 40b747bc3afb208b94fb1333c7cf1c12a10eb4aaac6d754adfd30593fba283bd. Source manifest: 8f61ec3aeca1a09ce8b40a075893ba3b9d459e358baeb6172188e97caa2e02a0.

Official source · 2021-09-27

Publication text

This is the complete recorded text of this dated publication.

Current legal effect is unknown. Aircraft applicability, installed configuration and compliance require separate evidence. PDF/text agreement has not been evaluated.

Read the complete official publication text
[Federal Register Volume 86, Number 184 (Monday, September 27, 2021)]
[Rules and Regulations]
[Pages 53203-53205]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2021-20829]


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

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2021-0513; Project Identifier 2018-SW-116-AD; Amendment 
39-21717; AD 2021-18-16]
RIN 2120-AA64


Airworthiness Directives; Bell Textron Canada Limited (Type 
Certificate Previously Held by Bell Helicopter Textron Canada Limited) 
Helicopters

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule.

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

SUMMARY: The FAA is adopting a new airworthiness directive (AD) for 
certain Bell Textron Canada Limited (Bell) Model 429 helicopters. This 
AD was prompted by reports of tail rotor gearbox assemblies found loose 
on the gearbox support. This AD requires repetitive torque checks of 
the tail rotor gearbox attachment hardware, and corrective action if 
necessary. The FAA is issuing this AD to address the unsafe condition 
on these products.

DATES: This AD is effective November 1, 2021.
    The Director of the Federal Register approved the incorporation by 
reference of a certain document listed in this AD as of November 1, 
2021.

ADDRESSES: For 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 [email protected]; or at https://www.bellflight.com/support/contact-support. You may view the referenced 
service information 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. It is also available at https://www.regulations.gov 
by searching for and locating Docket No. FAA-2021-0513.

Examining the AD Docket

    You may examine the AD docket at https://www.regulations.gov by 
searching for and locating Docket No. FAA-2021-0513; 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 
street 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: Darren Gassetto, Aerospace Engineer, 
COS Program Management Section, FAA, Operational Safety Branch, 
Compliance & Airworthiness Division, 1600 Stewart Avenue, Suite 410, 
Westbury, NY 11590; telephone (516) 228-7323; email 
[email protected].

SUPPLEMENTARY INFORMATION:

Background

    The FAA issued a notice of proposed rulemaking (NPRM) to amend 14 
CFR part 39 by adding an AD that would apply to certain Bell Textron 
Canada Limited (Bell) Model 429 helicopters. The NPRM published in the 
Federal Register on June 28, 2021 (86 FR 33918). In the NPRM, the FAA 
proposed to require repetitive torque checks of the tail rotor gearbox 
attachment hardware, and corrective action if necessary. The NPRM was 
prompted by Canadian AD CF-2018-35, dated December 19, 2018 (Canadian 
AD CF-2018-35), issued by Transport Canada, which is the aviation 
authority for Canada, to correct an unsafe condition for Bell Textron 
Canada Limited Model 429 helicopters. Transport Canada advises that 
there have been reports of tail rotor gearbox assemblies found loose on 
the gearbox support. Transport Canada issued Emergency Canadian 
Airworthiness Directive CF-2018-18, dated July 11, 2018, which 
corresponds to FAA AD 2018-16-51, Amendment 39-19421 (83 FR 53171, 
October 22, 2018), to address the immediate safety concern. An ongoing 
investigation determined that this condition-loose tail rotor gearbox 
assemblies-could return even after the corrective actions by the 
previous AD have been completed. This condition, if not addressed, 
could result in structural damage and possible loss of control of the 
helicopter.
    Accordingly, Canadian AD CF-2018-35 requires repetitive torque 
checks of the tail rotor gearbox attachment hardware and corrective 
actions if necessary. The corrective action is doing additional 
repetitive torque checks at intervals of 10 to 25 hours air time until 
the torque stabilizes on all the nuts.

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 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. Except for minor editorial changes, this AD is adopted as 
proposed in the NPRM.

Related Service Information Under 1 CFR Part 51

    The FAA reviewed Bell Alert Service Bulletin 429-18-41, dated July 
24, 2018. This service information specifies procedures for repetitive 
torque checks of the tail rotor gearbox attachment hardware.
    This service information 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 Transport Canada AD

    Where Canadian AD CF-2018-35 refers to ``200-hour'' inspections and 
``10 to 25 hours air time'' for the torque checks, for this AD use 
``time-in-service'' instead.

Costs of Compliance

    The FAA estimates that this AD affects 98 helicopters of U.S. 
Registry. The FAA estimates the following costs to comply with this AD:

[[Page 53204]]



                                      Estimated Costs for Required Actions
----------------------------------------------------------------------------------------------------------------
                                                                                     Cost per      Cost on U.S.
                Action                         Labor cost           Parts cost        product        operators
----------------------------------------------------------------------------------------------------------------
Torque check..........................  1 work-hour x $85 per                 $0             $85          $8,330
                                         hour = $85.
----------------------------------------------------------------------------------------------------------------

    The FAA estimates the following costs to do any necessary on-
condition actions that are required based on the results of any 
required actions. The FAA has no way of determining the number of 
helicopters that might need these on-condition actions:

                                     Estimated Costs of On-Condition Actions
----------------------------------------------------------------------------------------------------------------
                Action                        Labor cost          Parts cost            Cost per product
----------------------------------------------------------------------------------------------------------------
Repetitive torque check..............  1 work-hour x $85 per                $0  $85, per cycle.
                                        hour = $85, per cycle.
----------------------------------------------------------------------------------------------------------------

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 helicopters 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

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:

2021-18-16 Bell Textron Canada Limited (Type Certificate Previously 
Held by Bell Helicopter Textron Canada Limited): Amendment 39-21717; 
Docket No. FAA-2021-0513; Project Identifier 2018-SW-116-AD.

(a) Effective Date

    This airworthiness directive (AD) is effective November 1, 2021.

(b) Affected ADs

    None.

(c) Applicability

    This AD applies to Bell Textron Canada Limited (type certificate 
previously held by Bell Helicopter Textron Canada Limited) Model 429 
helicopters, certificated in any category, serial numbers 57001 and 
subsequent.

(d) Subject

    Joint Aircraft Service Component (JASC) Code: 6500, Tail Rotor 
Drive System; and 6520, Tail Rotor Gearbox.

(e) Unsafe Condition

    This AD was prompted by reports of tail rotor gearbox assemblies 
found loose on the gearbox support. The FAA is issuing this AD 
address tail rotor gearbox assemblies found loose on the gearbox 
support. The unsafe condition, if not addressed, could result in 
structural damage and possible loss of control of the helicopter.

(f) Compliance

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

(g) Required Actions

    Within 12 months after the effective date of this AD; or at the 
next scheduled 200-hours time-in-service (TIS) or 12-month 
inspection, whichever occurs first, do a torque check of the tail 
rotor gearbox attachment hardware, in accordance with the 
Accomplishment Instructions, paragraph 2., of Bell Alert Service 
Bulletin 429-18-41, dated July 24, 2018. Repeat the torque check 
thereafter at intervals not to exceed 200 hours TIS or 12 months, 
whichever occurs first.

(h) Corrective Actions

    If, during any torque check required by paragraph (g) of this 
AD, any tail rotor gearbox attachment moves during any torque check, 
repeat the torque check specified in paragraph (g) of this AD at 
intervals no less than 10 hours TIS and not to exceed 25 hours TIS 
until the torque stabilizes on all the nuts. Stabilization has 
occurred when, at the next torque check, the value has remained 
within the specified acceptable limits (160 to 200 inch-pounds (in-
lbs) or 19 to 22 newton meters (Nms), inclusive), preventing 
movement of the gearbox housing. After the torque stabilizes on all 
the nuts, the repetitive torque checks specified in paragraph (g) of 
this AD are still required.

(i) Credit for Previous Actions

    This paragraph provides credit for the initial torque check 
required by paragraph (g) of this AD, if that action was done before 
the effective date of this AD as required by paragraph (f)(2) of AD 
2018-16-51, Amendment 39-19421 (83 FR 53171, October 22, 2018).

(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

[[Page 53205]]

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)(1) of 
this AD. Information may be emailed 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.

(k) Related Information

    (1) For more information about this AD, contact Darren Gassetto, 
Aerospace Engineer, COS Program Management Section, FAA, Operational 
Safety Branch, Compliance & Airworthiness Division, 1600 Stewart 
Avenue, Suite 410, Westbury, NY 11590; telephone 516-228-7323; email 
[email protected].
    (2) The subject of this AD is addressed in Transport Canada AD 
CF-2018-35, dated December 19, 2018. You may view the Transport 
Canada AD at https://www.regulations.gov in Docket No. FAA-2021-
0513.

(l) Material Incorporated by Reference

    (1) The Director of the Federal Register approved the 
incorporation by reference of the service information listed in this 
paragraph under 5 U.S.C. 552(a) and 1 CFR part 51.
    (2) You must use this service information as applicable to do 
the actions required by this AD, unless the AD specifies otherwise.
    (i) Bell Alert Service Bulletin 429-18-41, dated July 24, 2018.
    (ii) [Reserved]
    (3) For service information identified in this AD, 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 [email protected]; or at https://www.bellflight.com/support/contact-support.
    (4) You may view this service information 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.
    (5) You may view this service information that is incorporated 
by reference at the National Archives and Records Administration 
(NARA). For information on the availability of this material at 
NARA, email: [email protected], or go to: https://www.archives.gov/federal-register/cfr/ibr-locations.html.

    Issued on August 26, 2021.
Gaetano A. Sciortino,
Deputy Director for Strategic Initiatives, Compliance & Airworthiness 
Division, Aircraft Certification Service.
[FR Doc. 2021-20829 Filed 9-24-21; 8:45 am]
BILLING CODE 4910-13-P


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Source SHA-256
089d1753dd5ad887d767118db2c47926521ae103badfedbd4eba1931f4ba7712
Text SHA-256
40b747bc3afb208b94fb1333c7cf1c12a10eb4aaac6d754adfd30593fba283bd

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These are dated publication metadata, recorded clauses and literal source observations. Word, model-label, header and reference matches do not establish current legal effect, manufacturer/model identity, aircraft applicability, installed configuration or compliance.

The collection uses 33 explicit annual source snapshots. Source captures and operative-text qualifications have separate states. Missing information remains unknown.