DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2018-0739; Product Identifier 2015-NE-07-AD; Amendment
39-19782; AD 2019-22-03]
RIN 2120-AA64

Airworthiness Directives; Pratt & Whitney Canada Corp. Turboshaft
Engines

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule.

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

SUMMARY: The FAA is superseding Airworthiness Directive (AD) 2015-20-04
for certain Pratt & Whitney Canada Corp. (P&WC) PT6B-37A turboshaft
engines. AD 2015-20-04 required initial and repetitive inspections
until replacement of the No. 10 bearing, and eventual replacement of
the No. 9 bearing, both located in the engine reduction gearbox (RGB)
assembly. This AD requires removal from service and replacement of the
No. 9 and No. 10 position bearings. This AD was prompted by reports of
incorrect engine torque for PT6B-37A turboshaft engines. The FAA is
issuing this AD to address the unsafe condition on these products.

DATES: This AD is effective December 24, 2019.
The Director of the Federal Register approved the incorporation by
reference of a certain publication listed in this AD as of December 24,
2019.

ADDRESSES: For service information identified in this final rule,
contact Pratt & Whitney Canada Corp., 1000 Marie-Victorin, Longueuil,
Quebec, Canada, J4G 1A1; phone: 800-268-8000; fax: 450-647-2888;
website: https://www.pwc.ca/en/. You may view this service information
at the FAA, Engine and Propeller Standards Branch, 1200 District
Avenue, Burlington, MA 01803. For information on the availability of
this material at the FAA, call 781-238-7759. It is also available on
the internet at https://www.regulations.gov by searching for and
locating Docket No. FAA-2018-0739.

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-2018-
0739; 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 mandatory continuing airworthiness information (MCAI),
regulatory evaluation, any comments received, and other information.
The 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: Barbara Caufield, Aerospace Engineer,
ECO Branch, FAA, 1200 District Avenue, Burlington, MA 01803; phone:
781-238-7146; fax: 781-238-7199; email: barbara.caufield@faa.gov.

SUPPLEMENTARY INFORMATION:

Discussion

The FAA issued a notice of proposed rulemaking (NPRM) to amend 14
CFR part 39 to supersede AD 2015-20-04, Amendment 39-18282 (80 FR
61717, October 14, 2015), (``AD 2015-20-04''). AD 2015-20-04 applied to
certain P&WC PT6B-37A turboshaft engines. The NPRM published in the
Federal Register on September 17, 2018 (83 FR 46898).
The NPRM was prompted by reports of incorrect engine torque for
PT6B-37A turboshaft engines. The NPRM proposed to require removal from
service and replacement of the No. 9 and No. 10 position bearings. The
FAA is issuing this AD to address the unsafe condition on these
products.
Transport Canada Civil Aviation, which is the aviation authority
for Canada, has issued Transport Canada AD CF-2015-01R1, dated November
18, 2016 (referred to after this as ``the MCAI''), to address the
unsafe condition on these products. The MCAI states:

Five incidents of incorrect engine torque indication have been
reported for PT6B-37A engine installations on AW119MKII helicopters.
A lower than actual engine torque indication due to a faulty
indication system, particularly on a helicopter being operated at
max allowable torque (90 to 110%) range, may result in undetected
over-torque condition.
Repeat undetected over-torque conditions that are not corrected
in accordance with conditional inspection requirements of original
equipment manufacturer (OEM) Instructions for Continued
Airworthiness (ICAs), may have a negative impact on the operational
life of aircraft components. Investigation by P&WC has determined
the root cause of the subject torque indication anomaly to be an
axial migration of the #9 and #10 bearings at the engine torque
sensing gear location.

P&WC has introduced a new bearing configuration through its SB No.
PT6B-72-39108, Revision No. 1, dated September 5, 2017, that
effectively addresses the axial movement issue at No. 9 and No. 10
bearing positions. You may obtain further information by examining the
MCAI in the AD docket on the internet at https://www.regulations.gov by
searching for and locating Docket No. FAA-2018-0739.

Comments

The FAA gave the public the opportunity to participate in
developing this AD. The following presents the comments received on the
NPRM and the FAA's response to each comment.

Support for the AD

An individual commenter expressed support for the NPRM as written.

Miscellaneous Comments

An individual commenter provided comments not relevant to this AD.
The FAA did not change this AD.

Update to the Service Information

The FAA determined the need to incorporate the latest service
information in this AD. The FAA revised the reference to P&WC SB No.
PT6B-72-39108 in the paragraph (g) of this AD from the original issue,
dated September 30, 2016, to Revision No. 1, dated September 5, 2017.
The FAA also updated the reference in paragraph (g) of this AD to
P&WC SB No. PT6B-72-39092 from Revision No. 4, dated December 29, 2014,
to Revision No. 5, dated October 27, 2017.

Addition of Credit for Previous Action

The FAA determined the need to add a Credit for Previous Action
section to allow credit for previous replacement of the No. 9 and No 10
position bearings if accomplished using P&WC SB No. PT6B-72-39108,
dated September 30, 2016.

Conclusion

The FAA reviewed the relevant data, considered the comments
received, and determined that air safety and the public interest
require adopting this AD as proposed except for minor editorial
changes. The FAA has determined that these minor changes:
Are consistent with the intent that was proposed in the
NPRM for addressing the unsafe condition; and
Do not add any additional burden upon the public than was
already proposed in the NPRM.

Related Service Information Under 1 CFR Part 51

The FAA reviewed P&WC SB No. PT6B-72-39108, Revision No. 1, dated
September 5, 2017. The SB describes procedures for replacing affected
bearings. 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.

Other Related Service Information

The FAA reviewed P&WC SB No. PT6B-72-39092, Revision No. 5, dated
October 27, 2017. The service information describes procedures for
removing affected bearings.

Costs of Compliance

The FAA estimates that this AD affects 119 engines installed on
helicopters of U.S. registry.
The FAA estimates the following costs to comply with this AD:

Estimated Costs

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.
This AD is issued in accordance with authority delegated by the
Executive Director, Aircraft Certification Service, as authorized by
FAA Order 8000.51C. In accordance with that order, issuance of ADs is
normally a function of the Compliance and Airworthiness Division, but
during this transition period, the Executive Director has delegated the
authority to issue ADs applicable to engines, propellers, and
associated appliances to the Manager, Engine and Propeller Standards
Branch, Policy and Innovation Division.

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.

Adoption of the Amendment

Accordingly, under the authority delegated to me by the
Administrator, the FAA amends part 39 of the Federal Aviation
Regulations (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 removing Airworthiness Directive (AD)
2015-20-04, Amendment 39-18282 (80 FR 61717, October 14, 2015), and
adding the following new AD: