DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2018-0834; Product Identifier 2018-SW-058-AD; Amendment
39-19421; AD 2018-16-51]
RIN 2120-AA64

Airworthiness Directives; Bell Helicopter Textron Canada Limited
Helicopters

AGENCY: Federal Aviation Administration (FAA), Department of
Transportation (DOT).

ACTION: Final rule; request for comments.

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SUMMARY: We are publishing a new airworthiness directive (AD) for Bell
Helicopter Textron Canada Limited (Bell) Model 429 helicopters. This AD
was sent previously to all known U.S. owners and operators of these
helicopters as Emergency AD 2018-16-51, dated July 26, 2018, which
superseded Emergency AD 2018-15-51, dated July 20, 2018. This AD
requires inspecting the tail rotor (T/R) gearbox installation,
inspecting the T/R gearbox retaining hardware and support attachment
point areas, and replacing each nut. This AD is prompted by two reports
of T/R gearbox assemblies loosely attached to the gearbox support. The
actions of this AD are intended to address an unsafe condition on these
products.

DATES: This AD becomes effective November 6, 2018 to all persons except
those persons to whom it was made immediately effective by Emergency AD
2018-16-51, issued on July 26, 2018, which contains the requirements of
this AD.

We must receive comments on this AD by December 21, 2018.

ADDRESSES: You may send comments by any of the following methods:

Federal eRulemaking Docket: Go to http://www.regulations.gov. Follow the
online instructions for sending your comments electronically.

Fax: 202-493-2251.

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 http://www.regulations.gov
by searching for and locating Docket No. FAA-2018-
0834; 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, the economic evaluation, any comments
received, and other information. The street address for Docket
Operations (telephone 800- 647-5527) is in the ADDRESSES section.
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 http://www.bellcustomer.com/files/. 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.

FOR FURTHER INFORMATION CONTACT: Matt Fuller, Senior Aviation Safety
Engineer, Safety Management Section, Rotorcraft Standards Branch, FAA,
10101 Hillwood Pkwy., Fort Worth, TX 76177; telephone (817) 222-5110;
email matthew.fuller@faa.gov.

SUPPLEMENTARY INFORMATION:

Comments Invited

This AD is a final rule that involves requirements affecting flight
safety, and we did not provide you with notice and an opportunity to
provide your comments prior to it becoming effective. However, we
invite you to participate in this rulemaking by submitting written
comments, data, or views. We also invite 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. We will file in the docket all comments that
we receive, as well as a report summarizing each substantive public
contact with FAA personnel concerning this rulemaking during the
comment period. We will consider all the comments we receive and may
conduct additional rulemaking based on those comments.

Discussion

Transport Canada, which is the aviation authority for Canada,
issued Emergency AD No. CF-2018-18, dated July 11, 2018, to correct an
unsafe condition for Bell Model 429 helicopters. Transport Canada
advises of two reports of T/R gearbox assemblies loosely attached to
the gearbox support. According to Transport Canada, this condition
could lead to structural damage and possible loss of control of the
helicopter.

As a result, on July 20, 2018, we issued Emergency AD 2018-15-51
(Emergency AD 2018-15-51), which required inspecting the T/R gearbox
installation for looseness, visually inspecting the T/R gearbox
retaining hardware and support attachment point areas, and torque
inspecting the gearbox retaining nuts. Depending on the inspection
results, Emergency AD 2018-15-51 required replacing or repairing the
affected parts in accordance with FAA-approved procedures. Emergency AD
2018-15-51 was sent previously to all known U.S. owners and operators
of these helicopters. The actions in Emergency AD 2018-15-51 were
intended to prevent detachment of the T/R gearbox, loss of T/R control,
and loss of control of the helicopter.

After we issued Emergency AD 2018-15-51, we discovered an error in
the replacement nut P/N. The required replacement nut P/N is NAS9926-
6L; not NAS9926-5L as incorrectly stated in Emergency AD 2018-15-51.
Therefore, on July 26, 2018, we issued Emergency AD 2018-16-51 to
supersede Emergency AD 2018-15-51 to correct the nut P/N. Emergency AD
2018-16-51 otherwise retains all of the requirements of Emergency AD
2018-15-51. Emergency AD 2018-16-51 was also sent previously to all
known U.S. owners and operators of these helicopters.

FAA's Determination

These helicopters have been approved by the aviation authority of
Canada and are approved for operation in the United States. Pursuant to
our bilateral agreement with Canada, Transport Canada, its technical
representative, has notified us of the unsafe condition described in
the Transport Canada AD. We are issuing this AD because we 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 design.

Related Service Information

We reviewed Bell Alert Service Bulletin 429-18-40, dated July 6,
2018, which specifies a one-time inspection of the T/R gearbox
installation and a one-time visual and torque inspection of the six
installation attachment points. This service information also specifies
contacting Bell Product Support Engineering with the results of the T/R
gearbox installation inspection, any findings of the visual inspection,
and the results of the torque inspection.

AD Requirements

This AD requires inspecting the T/R gearbox installation for
looseness, visually inspecting the T/R gearbox retaining hardware and
each support attachment point area, and torque inspecting each gearbox
retaining nut. Depending on the inspection results, this AD requires
replacing or repairing the affected parts in accordance with FAA-
approved procedures.

Differences Between This AD and the Transport Canada AD

The Transport Canada AD applies to helicopters with specific serial
numbers, whereas this AD applies to all Model 429 helicopters. The
Transport Canada AD includes a calendar based compliance time, whereas
this AD does not. The Transport Canada AD requires reporting certain
information to Bell Product Support Engineering and this AD does not.
If there is looseness, this AD requires performing the visual
inspection and torque inspection before further flight, while the
Transport Canada AD requires contacting Bell. Lastly, if the torque of
a T/R gearbox retaining nut is below 160 in-lbs (19 Nm), this AD
requires removing the T/R gearbox and inspecting the mounting surfaces
and retaining hardware, while the Transport Canada AD requires
contacting Bell.

Interim Action

We consider this AD to be an interim action. If final action is
later identified, we might consider further rulemaking then.

Costs of Compliance

We estimate that this AD affects 90 helicopters of U.S. Registry.
We estimate that operators may incur the following costs in order to
comply with this AD. Labor costs are estimated at $85.00 per work-hour.

Inspecting the T/R gearbox installation takes about 0.25 work-hour
for an estimated cost of $21 per helicopter and $1,890 for the U.S.
fleet. Inspecting the T/R gearbox retaining hardware and the support
attachment points takes about 0.5 work-hour for an estimated cost of
$43 per helicopter and $3,870 for the U.S. fleet. Replacing the nuts
takes about 1 work-hour and parts cost about $20 for an estimated cost
of $105 per helicopter and $9,450 for the U.S. fleet.

FAA's Justification and Determination of the Effective Date

An unsafe condition exists that required the immediate adoption of
Emergency AD 2018-16-51, issued on July 26, 2018, to all known U.S.
owners and operators of these helicopters. The FAA found that the risk
to the flying public justified waiving notice and comment prior to
adoption of this rule because there are required actions that must be
completed before further flight and within 5 hours time-in-service.
These conditions still exist and the AD is hereby published in the
Federal Register as an amendment to section 39.13 of the Federal
Aviation Regulations (14 CFR 39.13) to make it effective to all
persons. Therefore, we find good cause that notice and opportunity for
prior public comment are impracticable. In addition, for the reasons
stated above, we find that good cause exists 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.

We are 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

We 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 12866;

2. Is not a "significant rule" under DOT Regulatory Policies and
Procedures (44 FR 11034, February 26, 1979);

3. Will not affect intrastate aviation in Alaska to the extent that
it justifies making a regulatory distinction; and

4. 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.

We prepared an economic evaluation of the estimated costs to comply
with this AD and placed it in the AD docket.

List of Subjects in 14 CFR Part 39

Air transportation, Aircraft, Aviation safety, Incorporation by
reference, Safety.

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
directive (AD):