DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2020-0221; Product Identifier 2019-SW-042-AD; Amendment
39-19862; AD 2020-04-21]
Airworthiness Directives; Bell Helicopter Textron Canada Limited
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Final rule; request for comments.
SUMMARY: The FAA is adopting a new airworthiness directive (AD)
certain Bell Helicopter Textron Canada Limited (Bell Canada) Model 429
helicopters. This AD requires inspecting a certain part-numbered curvic
coupling for proper engagement and depending on the inspection results,
inspecting for play, inspecting the curvic coupling teeth, inspecting
the flapping bearing teeth, replacing parts, performing a rigging
check, and reporting information. This AD was prompted by a report of
disengaged teeth of a curvic coupling due to improper installation. The
actions of this AD are intended to address an unsafe condition on these
DATES: This AD becomes effective March 31, 2020.
The Director of the Federal Register approved the incorporation by
reference of a certain document listed in this AD as of March 31, 2020.
The FAA must receive comments on this AD by May 15, 2020.
ADDRESSES: You may send comments by any of the following methods:
Federal eRulemaking Docket: Go to https://www.regulations.gov. Follow
instructions for sending your comments electronically.
Mail: Send comments to the U.S. Department of
Transportation, Docket Operations, M-30, West Building Ground Floor,
Room W12-140, 1200 New Jersey Avenue SE, Washington, DC 20590-0001.
Hand Delivery: Deliver to the ``Mail'' address between 9
a.m. and 5 p.m., Monday through Friday, except Federal holidays.
Examining the AD Docket
You may examine the AD docket on the internet at https://www.regulations.gov
by searching for and locating Docket No. FAA-2020-
0221; 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 AD, the Transport Canada AD, any service information that is
incorporated by reference, any comments received, and other
information. The street address for Docket Operations is listed above.
Comments will be available in the AD docket shortly after receipt.
For service information identified in this final rule, contact Bell
Helicopter Textron Canada Limited, 12,800 Rue de l'Avenir, Mirabel,
Quebec J7J1R4; telephone 450-437-2862 or 800-363-8023; fax 450-433-
0272; or at https://www.bellcustomer.com. You may review the referenced
service information at the FAA, Office of the Regional Counsel,
Southwest Region, 10101 Hillwood Pkwy, Room 6N-321, Fort Worth, TX
76177. It is also available on the internet at https://www.regulations.gov
for and locating Docket No. FAA-2020-0221.
FOR FURTHER INFORMATION CONTACT: Kristi Bradley, Aerospace Engineer,
Safety Management Section, Rotorcraft Standards Branch, FAA, 10101
Hillwood Pkwy., Fort Worth, TX 76177; telephone 817-222-5110; email
This AD is a final rule that involves requirements affecting flight
safety, and the FAA did not provide you with notice and an opportunity
to provide your comments prior to it becoming effective. However, the
FAA invites you to participate in this rulemaking by submitting written
comments, data, or views. The FAA also invites comments relating to the
economic, environmental, energy, or federalism impacts that resulted
from adopting this AD. The most helpful comments reference a specific
portion of the AD, explain the reason for any recommended change, and
include supporting data. To ensure the docket does not contain
duplicate comments, commenters should send only one copy of written
comments, or if comments are filed electronically, commenters should
submit them only one time. The FAA will file in the docket all comments
received, as well as a report summarizing each substantive public
contact with FAA personnel concerning this rulemaking during the
comment period. The FAA will consider all the comments received and may
conduct additional rulemaking based on those comments.
Transport Canada, which is the aviation authority for Canada, has
issued Emergency AD No. CF-2019-15, dated April 26, 2019, to correct an
unsafe condition for Bell Canada Model 429 helicopters, serial numbers
57001 through 57363. Transport Canada advises of a report of an
improperly installed curvic coupling part number (P/N) 429-012-120-101.
This was discovered during installation of the tail rotor (T/R) hub and
blade assembly when the teeth of the curvic coupling rested on top of
each other instead of meshing together. Transport Canada further
advises that this condition may result in loosening of the T/R assembly
and subsequent vibration and loss of drive to the outboard T/R blades,
which will result in degraded directional control. Therefore, the
Transport Canada Emergency AD requires inspecting the T/R and
correcting any defective conditions, as well as reporting any anomalies
to Bell Canada.
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 the Transport Canada AD. The FAA is issuing this AD
because it has evaluated all information provided by Transport Canada
and determined the unsafe condition exists and is likely to exist or
develop on other helicopters of the same type designs.
Related Service Information Under 1 CFR Part 51
Bell has issued Alert Service Bulletin 429-19-45, dated April 16,
2019, for Model 429 helicopters, serial numbers 57001 through 57343,
57346 through 57349, 57352 through 57356, and 57362. This service
information specifies inspecting the inboard and outboard curvic
coupling teeth for proper engagement; inspecting for axial play between
the inboard and outboard hub and blade assemblies; inspecting for play
between the curvic coupling teeth and both inboard and outboard
flapping bearing teeth; inspecting the curvic coupling teeth for
damage; inspecting the inboard and outboard flapping bearing teeth for
damage; installing a serviceable T/R hub and blade assembly; performing
a rigging check of the directional control system; and reporting any
anomalies to Bell Canada.
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.
This AD requires inspecting the curvic coupling teeth for proper
engagement with the inboard and outboard flapping bearing teeth within
10 hours time-in-service (TIS).
If the teeth are not properly engaged, this AD requires removing
the T/R hub and blade assembly and inspecting the curvic coupling teeth
and the inboard and outboard flapping bearing teeth for a crack, wear,
mechanical damage, and corrosion. Depending on the inspection results,
this AD requires replacing parts. Then, with the T/R hub and blade
assembly installed, this AD requires
performing a rigging check of the directional control system.
If the teeth are properly engaged, this AD requires inspecting for
axial play between both the inboard and outboard T/R hub and blade
assemblies. If there is axial play, this AD requires performing the
inspections for a crack, wear, mechanical damage, and corrosion. If
there is no axial play, this AD requires inspecting for play between
the teeth of the curvic coupling and both the inboard and outboard
flapping bearing teeth, and if play exists, this AD requires performing
the inspections for a crack, wear, mechanical damage, and corrosion.
Lastly, this AD requires emailing information about the inspection
results that resulted in the replacement of parts to Bell Canada.
Differences Between This AD and the Transport Canada AD
The Transport Canada Emergency AD requires reporting information
within 3 days after the completion of the inspection, whereas this AD
allows a compliance time of up to 10 days after completion of the
inspection instead. This AD applies to fewer serial numbered Model 429
helicopters, listed in the applicability section, than the Transport
Canada Emergency AD because certain serial numbered helicopters will
have complied with the intent of this AD prior to delivery.
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 notice and comment,
RFA analysis is not required.
Costs of Compliance
The FAA estimates that this AD affects 88 helicopters of U.S.
Registry. The FAA estimates that operators may incur the following
costs in order to comply with this AD. Labor costs are estimated at $85
Inspecting the curvic coupling teeth and the flapping bearing teeth
for proper engagement requires about 0.5 work-hours for an estimated
cost of $43 per helicopter and $3,784 for the U.S. fleet.
If required, removing and installing the T/R hub and blade assembly
to inspect the curvic coupling teeth and the inboard and outboard
flapping bearing teeth for a crack, wear, mechanical damage, and
corrosion requires about 0.5 work-hours for an estimated cost of $43
Replacing a curvic coupling requires about 0.5 work-hours and parts
cost about $4,141 for an estimated cost of $4,184 per curvic coupling.
Replacing a flapping bearing requires about 0.5 work-hours and
parts cost about $19,948 for an estimated cost of $19,991 per flapping
If required, reporting information takes about 1 work-hour for an
estimated cost of $85 per helicopter.
Paperwork Reduction Act
A federal agency may not conduct or sponsor, and a person is not
required to respond to, nor shall a person be subject to a penalty for
failure to comply with a collection of information subject to the
requirements of the Paperwork Reduction Act unless that collection of
information displays a currently valid OMB Control Number. The OMB
Control Number for this information collection is 2120-0056. Public
reporting for this collection of information is estimated to be
approximately 1 hour per response, including the time for reviewing
instructions, searching existing data sources, gathering and
maintaining the data needed, and completing and reviewing the
collection of information. All responses to this collection of
information are mandatory. Send comments regarding this burden estimate
or any other aspect of this collection of information, including
suggestions for reducing this burden to: Information Collection
Clearance Officer, Federal Aviation Administration, 10101 Hillwood
Parkway, Fort Worth, TX 76177-1524.
Justification for Immediate Adoption and Determination of the Effective
Section 553(b)(3)(B) of the Administrative Procedure Act (5 U.S.C.)
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 seeking comment prior to the rulemaking.
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 waiving notice and comment prior to adoption of this rule
because the unsafe condition requires corrective action within 10 hours
TIS. Accordingly, notice and opportunity for prior public comment are
impracticable and contrary to public interest pursuant to 5 U.S.C.
553(b)(3)(B). In addition, for the reasons stated above, 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.
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.
The FAA 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, I certify that this AD:
1. Is not a ``significant regulatory action'' under Executive Order
2. Will not affect intrastate aviation in Alaska.
List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation safety, Incorporation by
Adoption of 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 adding the following new airworthiness