DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2021-0513; Project Identifier 2018-SW-116-AD]
Airworthiness Directives; Bell Textron Canada Limited (Type
Certificate Previously Held by Bell Helicopter Textron Canada Limited)
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Notice of proposed rulemaking (NPRM).
SUMMARY: The FAA proposes to adopt a new airworthiness directive
for certain Bell Textron Canada Limited (Bell) Model 429 helicopters.
This proposed AD was prompted by reports of tail rotor gearbox
assemblies found loose on the gearbox support. This proposed AD would
require repetitive torque checks of the tail rotor gearbox attachment
hardware, and corrective action if necessary. The FAA is proposing this
AD to address the unsafe condition on these products.
DATES: The FAA must receive comments on this proposed AD by August
ADDRESSES: You may send comments, using the procedures found in
11.43 and 11.45, by any of the following methods:
Federal eRulemaking Portal: Go to https://www.regulations.gov. Follow
instructions for submitting comments.
Fax: (202) 493-2251.
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.
Hand Delivery: Deliver to Mail address between 9 a.m. and
5 p.m., Monday through Friday, except Federal holidays.
For service information identified in this NPRM, 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@example.com; or at https://www.bellflight.
com/support/contact-support. 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)
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 NPRM, the
Transport Canada AD, any comments received, and other information. The
street address for Docket Operations is listed above.
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
The FAA invites you to send any written relevant data, views, or
arguments about this proposal. Send your comments to an address listed
under ADDRESSES. Include "Docket No. FAA-2021-0513; Project Identifier
2018-SW-116-AD" at the beginning of your comments. The most helpful
comments reference a specific portion of the proposal, 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 proposal 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
https://www.regulations.gov, including any personal information you
provide. The agency will also post a report summarizing each
substantive verbal contact received about this NPRM.
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 NPRM 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 NPRM, 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 NPRM. Submissions containing CBI should be sent to 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 Darren.Gassetto@faa.gov. Any commentary that the FAA receives which
is not specifically designated as CBI will be placed in the public docket
for this rulemaking.
Transport Canada Civil Aviation (TCCA), which is the aviation
authority for Canada, has issued Canadian AD CF-2018-35, dated December
19, 2018 (Canadian AD CF-2018-35), 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
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.
The helicopter has been approved by the aviation authority of
Canada and is 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 is proposing this AD after evaluating all
known relevant information and determining that the unsafe condition
described previously is likely to exist or develop on other helicopters
of the same type design.
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.
Proposed AD Requirements in This NPRM
This proposed AD would require accomplishing the actions specified
in the service information already described, except as discussed under
"Differences Between this Proposed AD and the Transport Canada AD."
Differences Between This Proposed 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 proposed AD
use "time-in-service" instead.
Costs of Compliance
The FAA estimates that this AD, if adopted as proposed, would affect 98
helicopters of U.S. Registry. The FAA estimates the following costs to
comply with this proposed AD:
Estimated Costs for Required Actions
||1 work-hour x $85 per hour =
The FAA estimates the following costs
to do any necessary on-
condition actions that would be 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
|Repetitive torque check
||1 work-hour x $85 per hour =
$85, per cycle
|$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 products identified in this rulemaking action.
The FAA determined that this proposed AD would not have federalism
implications under Executive Order 13132. This proposed AD would 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 this proposed regulation:
(1) Is not a "significant regulatory action" under Executive
(2) Would not affect intrastate aviation in Alaska, and
(3) Would 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
The Proposed Amendment
Accordingly, under the authority delegated to me by the
Administrator, the FAA proposes to amend 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