DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2019-0589; Product Identifier 2017-SW-020-AD; Amendment
39-21215; AD 2020-17-10]
RIN 2120-AA64

Airworthiness Directives; Bell Helicopter 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) 2016-02-06
for Bell Helicopter Textron Canada Limited (Bell) Model 429
helicopters. AD 2016-02-06 required inspecting certain tail rotor (T/R)
pitch link bearing bores for corrosion and pitting. AD 2016-02-06 also
required a repetitive inspection of the sealant and repeating the
inspections for corrosion and pitting if any sealant is missing. This
new AD retains the requirements of AD 2016-02-06, expands the
applicability, and adds a repetitive inspection. This AD was prompted
by an FAA determination that additional part-numbered T/R pitch link
assemblies (links) are affected by the same unsafe condition and that
an additional repetitive inspection is necessary to address the unsafe
condition. The actions of this AD are intended to address an unsafe
condition on these products.

DATES: This AD is effective September 21, 2020.

The Director of the Federal Register approved the incorporation by
reference of a certain publication listed in this AD as of February 2,
2016 (81 FR 5367, February 2, 2016).

ADDRESSES: 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 view this
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
by searching for and locating Docket No. FAA-2019-0589.

Examining the AD Docket

You may examine the AD docket on the internet at https://www.regulations.gov
in Docket No. FAA-2019-0589; 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 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: Scott Franke, Aviation Safety
Engineer, International Validation Branch, Aviation and Rotorcraft
Unit, FAA, 10101 Hillwood Pkwy., Fort Worth, TX 76177; telephone 817-
222-5110; email scott.franke@faa.gov.

SUPPLEMENTARY INFORMATION:

Discussion

The FAA issued a notice of proposed rulemaking (NPRM) to amend 14
CFR part 39 to remove AD 2016-02-06, Amendment 39-18387 (81 FR 5367,
February 2, 2016) ("AD 2016-02-06") and add a new AD. AD 2016-02-06
applied to Bell Model 429 helicopters with a T/R link part number (P/N)
429-012-112-101, -101FM, -103, or -103FM installed. The NPRM published
in the Federal Register on August 20, 2019 (84 FR 43085). Since the FAA
issued AD 2016-02-06, improved T/R links P/N 429-012-112-111 and -113
were developed, but recurring inspections of the sealant of these T/R
links are still necessary because they are subject to the same unsafe
condition due to design similarity. Some T/R links P/N 429-012-112-101
and -103 have also been field modified and re-identified as T/R links
P/N 429-012-112-111FM and -113FM, and continue to need recurring
inspections of the sealant as they are also subject to the same unsafe
condition due to design similarity.

The NPRM proposed to continue the requirements of AD 2016-02-06 and
add P/Ns 429-012-112-111, -111FM, -113, and -113FM to the
applicability. The NPRM also proposed to add use of 10X or higher power
magnification to the visual inspection of each cleaned T/R link for
pitting and a repetitive 12-month inspection with the corrosion
preventative sealant removed.

Transport Canada, which is the aviation authority for Canada,
issued AD No. CF-2016-01R2, dated April 12, 2017 (AD CF-2016-01R2) to
clarify the applicable P/Ns, address spare parts, and address parts
installed on-condition prior to December 7, 2015. AD CF-2016-01R2 also
includes a terminating action for the repetitive inspections.

Comments

After the NPRM was published, the FAA received comments from one commenter.

Request

Bell Textron, Inc., commented that this AD omits Bell Helicopter
Alert Service Bulletin (ASB) 429-15-16 Rev. B, dated June 15, 2016 (ASB
429-15-16 Rev. B), which was issued after Bell Helicopter ASB 429-15-
26, dated December 7, 2015 (ASB 429-15-26). The FAA acknowledges that
ASB 429-15-16 Rev. B and ASB 429-15-26 specify procedures for the same
part-numbered T/R links. However, the two service information documents
address different unsafe conditions, specifically ASB 429-15-16 Rev. B
addresses wear and ASB 429-15-26 addresses corrosion. Accordingly, the
two different unsafe conditions are addressed in two separate ADs. The
unsafe condition of wear (ASB 429-15-16 Rev. B) is addressed in AD
2019-11-05, Amendment 39-19651 (84 FR 26546, June 7, 2019) ("AD 2019-
11-05"). The unsafe condition of corrosion (ASB 429-15-26) is
addressed in this AD. The FAA did not change this AD based on this comment.

Bell Textron, Inc., commented that this AD differs from ASB 429-15-
16 Rev. B and ASB 429-15-26 by requiring removal of the sealant around
the bearing every 12 months and an inspection of the chamfer with a 10X
magnifying lens. Bell Textron, Inc., stated that since ASB 429-15-16
Rev. B "requires" a repetitive 50 flight hours inspection of the
sealant for pin holes and voids, it does not feel the repetitive 12
month inspection with the sealant removed is necessary. The FAA
disagrees. Procedures specified in related service information
documents are not required unless mandated by an AD. And while AD 2019-
11-05 mandates the repetitive inspection of the sealant condition for
pin holes and voids specified in ASB 429-15-16 Rev. B, the FAA
determined an inspection with the sealant removed at a longer-term
repetitive interval is necessary. Since sealant could become damaged,
not maintain seal, or become worn, this more in-depth inspection
addresses corrosion and pitting that could build up underneath the
sealant. The FAA did not change this AD based on this comment.

Bell Textron, Inc., commented that not requiring part re-
identification makes it more complicated to manage configurations. The
FAA does not prohibit re-identifying the T/R links as specified in ASB
429-15-26; however, the FAA determined it unnecessary to require to
address the unsafe condition since the repetitive inspections are
required for all part-numbered links listed in the applicability. The
FAA did not change this AD based on this comment.

FAA's Determination

The FAA has reviewed the relevant information and determined that
an unsafe condition exists and is likely to exist or develop on other
helicopters of the same type design and that air safety and the public
interest require adopting the AD requirements as proposed except for
editorial changes. The website URL for Bell and the email address for
requesting an alternative method of compliance have changed and have
been updated in this final rule. Additionally, the paragraph cross-
referencing formatting in the Required Actions paragraph has changed to
meet current publication requirements, e.g., "(f)(3)(i) and
(f)(3)(ii)" has changed to "(f)(3)(i) and (ii)" instead. These
editorial changes are consistent with the intent of the proposals in
the NPRM and will not increase the economic burden on any operator nor
increase the scope of the AD.

Interim Action

The FAA considers this AD to be an interim action. The design
approval holder is currently developing a modification that will
address the unsafe condition identified in this AD. Once this
modification is developed, approved, and available, the FAA might
consider additional rulemaking.

Differences Between This AD and the Transport Canada AD

This AD applies to helicopters with certain link P/Ns installed,
whereas the Transport Canada AD applies to helicopters with certain
serial numbers instead. This AD requires inspecting the bearing bores
for any pitting after cleaning the T/R link, while the Transport Canada
AD requires inspecting for corrosion after cleaning the T/R link. This
AD requires performing the inspections with 10X or higher
magnification, while the Transport Canada AD does not specify any
magnification. This AD does not require re-identifying the P/N of the
link, whereas the Transport Canada AD does. The Transport Canada AD
also provides a terminating action to the repetitive sealant
inspection, while this AD does not. This AD also requires a repetitive
inspection with the corrosion preventative sealant removed and
reapplied, whereas the Transport Canada AD does not.

Related Service Information Under 1 CFR Part 51

The FAA reviewed ASB 429-15-26, which advises of reports of
corrosion on T/R links between the roll staked lip of bearing P/N 429-
312-107-103 and the beveled edge of T/R link P/Ns 429-012-112-101/-103.
ASB 429-15-26 specifies inspecting each T/R link bearing bore between
the roll staked lip of the bearing outer race and the link bearing bore
with 10X magnification for corrosion and if there is corrosion,
replacing the link. If there is no corrosion, ASB 429-15-26 specifies
cleaning the area and performing a second inspection with 10X
magnification for corrosion. If there is corrosion, ASB 429-15-26
specifies replacing the link. If there is no corrosion, ASB 429-15-26
specifies removing the torque stripe, cleaning the area, and applying
corrosion preventative sealant. ASB 429-15-26 also specifies re-
identifying the P/Ns as 429-012-112-101FM/-103FM. Further, ASB 429-15-
26 specifies a repetitive inspection of the sealant and reapplication
if the sealant is damaged.

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.

Costs of Compliance

The FAA estimates that this AD affects 93 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
per work-hour.

Inspecting the set of T/R links (eight bearings) for corrosion
takes about one work-hour for an estimated cost of $85 per helicopter
and $7,905 for the U.S. fleet per inspection cycle. Cleaning and
inspecting the set of T/R links for pitting takes about one work-hour
for an estimated cost of $85 per helicopter. Replacing a T/R link
requires no additional work-hours after the inspection and required
parts cost $2,739 for an estimated replacement cost of $2,739 per T/R
link. Removing the torque stripe, cleaning, and applying sealant to the
set of T/R links takes about one work-hour with a negligible parts cost
for an estimated cost of $85 per helicopter. Inspecting the sealant on
a set of T/R links takes about one work-hour for an estimated cost of
$85 per helicopter and $7,905 for the U.S. fleet per inspection cycle.

According to Bell Helicopter's service information, some of the
costs of this AD may be covered under warranty, thereby reducing the
cost impact on affected individuals. The FAA does not control warranty
coverage by Bell Helicopter. Accordingly, the FAA has included all
costs in this cost estimate.

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

The FAA has 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 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.

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:

a. Removing Airworthiness Directive (AD) 2016-02-06, Amendment 39-18387
(81 FR 5367, February 2, 2016); and

b. Adding the following new AD: