DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2020-0471; Project Identifier MCAI-2019-00126-E]
RIN 2120-AA64

Airworthiness Directives; Pratt & Whitney Canada Corp. Turboshaft
Engines

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: The FAA proposes to adopt a new airworthiness directive (AD)
for all Pratt & Whitney Canada Corp. (P&WC) PT6B-37A model turboshaft
engines with engine serial number PCE-PU0289 and earlier. This proposed
AD was prompted by a report of contamination from galvanic corrosion
between the fuel control unit (FCU) aluminum body and the steel union
fitting causing the loss of engine control, resulting in an engine
over-speed condition and subsequent in-flight shutdown (IFSD). This
proposed AD would require replacing the FCU with a part eligible for
installation. 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 June 29, 2020.

ADDRESSES: You may send comments, using the procedures found in 14 CFR
11.43 and 11.45, by any of the following methods:

Federal eRulemaking Portal: Go to https://www.regulations.gov. Follow the
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 above between 9
a.m. and 5 p.m., Monday through Friday, except Federal holidays.

For service information identified in this NPRM, 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,
Airworthiness Products Section, Operational Safety Branch, 1200
District Avenue, Burlington, MA, 01803. For information on the
availability of this material at the FAA, call 781-238-7759.

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-2020-0471;
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 mandatory continuing airworthiness information (MCAI),
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 FURTHER INFORMATION CONTACT: Mehdi Lamnyi, Aerospace Engineer, ECO
Branch, FAA, 1200 District Avenue, Burlington, MA, 01803; phone: 781-
238-7743; fax: 781-238-7199; email: Mehdi.Lamnyi@faa.gov.

SUPPLEMENTARY INFORMATION:

Comments Invited

The FAA invites you to send any written relevant data, views, or
arguments about this proposal. Send your comments to an address listed
under the ADDRESSES section. Include "Docket No. FAA-2020-0471;
Project Identifier MCAI-2019-00126-E" at the beginning of your
comments. The FAA specifically invites comments on the overall
regulatory, economic, environmental, and energy aspects of this NPRM.
The FAA will consider all comments received by the closing date and may
amend this NPRM because of those comments.

Except for Confidential Business Information 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 FAA will also post a report summarizing each substantive
verbal contact received about this NPRM.

Confidential Business Information

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 Mehdi Lamnyi, Aerospace Engineer, ECO Branch,
FAA, 1200 District Avenue, Burlington, MA, 01803. Any commentary that
the FAA receives which is not specifically designated as CBI will be
placed in the public docket for this rulemaking.

Discussion

Transport Canada Civil Aviation (Transport Canada), which is the
aviation authority for Canada, has issued Transport Canada AD CF-2019-
05, dated February 19, 2019 (referred to after this as "the MCAI"),
to address the unsafe condition on these products. The MCAI states:

There has been one reported incident on a PT6B-37A engine, where
the contamination from galvanic corrosion between the FCU aluminum
body and the steel union fitting has caused the loss of engine
control, resulting in an engine over-speed condition and
subsequently leading to an engine inflight shutdown (IFSD). This
condition, if not corrected, could lead to additional cases of
IFSDs, which on a single engine helicopter may result in an
emergency autorotation landing. To address the subject galvanic
corrosion problem in the FCU, P&WC has issued Service Bulletin (SB)
39107 to replace the affected FCUs with a modified FCU that is not
susceptible to the subject galvanic corrosion problem. This
[Transport Canada] AD mandates compliance with P&WC SB 39107,
requiring the replacement of the
affected FCUs to mitigate the potential unsafe condition.

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-2020-0471.

Related Service Information Under 1 CFR Part 51

The FAA reviewed P&WC Service Bulletin (SB) No. PT6B-72-39107,
Revision No. 1, dated December 13, 2017. The SB describes procedures
for replacing the FCU. 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.

FAA's Determination

This product has been approved by the aviation authority of Canada
and is 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
MCAI and service information referenced above. The FAA is proposing
this AD because it evaluated all the relevant information provided by
Transport Canada and determined the unsafe condition described
previously is likely to exist or develop in other products of the same
type design.

Proposed AD Requirements

This proposed AD would require replacing the FCU with a part
eligible for installation.

Differences Between This Proposed AD and the Service Information

P&WC SB No. PT6B-72-39107, Revision No. 1, dated December 13, 2017,
directs the replacement of both the FCU and the bypass valve cover.
This proposed AD requires only the replacement of the FCU.

Costs of Compliance

The FAA estimates that this proposed AD affects 75 engines
installed on helicopters of U.S. registry.

The FAA estimates the following costs to comply with this proposed
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.

Regulatory Findings

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 above, I certify this proposed
regulation:

(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.

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
directive (AD):