[4910-13-P]

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2015-0486; Directorate Identifier 2015-NE-07-AD]

RIN 2120-AA64

Airworthiness Directives; Pratt & Whitney Canada Corp. Turboshaft Engines

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

SUMMARY: We propose to adopt a new airworthiness directive (AD) for certain Pratt 

& Whitney Canada Corp. (P&WC) PT6B-37A turboshaft engines. This proposed AD 

was prompted by reports of incorrect engine torque for PT6B-37A engines. This 

proposed AD would require 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. We are proposing this AD to prevent axial migration 

of the No. 10 bearing in the engine RGB assembly, which could lead to engine 

overtorque, failure of the engine, in-flight shutdown, and loss of the rotorcraft.

DATES: We must receive comments on this proposed AD by [INSERT DATE 60 

DAYS AFTER DATE OF PUBLICATION IN THE FEDERAL REGISTER].

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

• Federal eRulemaking Portal: Go to http://www.regulations.gov. Follow the 

instructions for submitting comments.
• Mail: Docket Management Facility, U.S. Department of Transportation, 1200 

New Jersey Avenue SE., West Building Ground Floor, Room W12-140, Washington, DC 

20590-0001.

• Hand Delivery: Deliver to Mail address above between 9 a.m. and 5 p.m., 

Monday through Friday, except Federal holidays.

• Fax: 202-493-2251.

For service information identified in this proposed AD, contact Pratt & Whitney

Canada Corp., 1000 Marie-Victorin, Longueuil, Quebec, Canada, J4G 1A1; phone: 800-

268-8000; fax: 450-647-2888; Web site: www.pwc.ca. You may view this service 

information at the FAA, Engine & Propeller Directorate, 12 New England Executive 

Park, Burlington, MA. For information on the availability of this material at the FAA, 

call 781-238-7125. 

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-2015-0486; or in person at the Docket 

Operations office between 9 a.m. and 5 p.m., Monday through Friday, except Federal 

holidays. The AD docket contains this proposed AD, the mandatory continuing 

airworthiness information (MCAI), the regulatory evaluation, any comments received, 

and other information. The address for the Docket Office (phone: 800-647-5527) is in the 

ADDRESSES section. Comments will be available in the AD docket shortly after receipt.

FOR FURTHER INFORMATION CONTACT: Barbara Caufield, Aerospace 

Engineer, Engine Certification Office, FAA, Engine & Propeller Directorate, 12 New 

2
England Executive Park, Burlington, MA 01803; phone: 781-238-7146; fax: 781-238-

7199; email: barbara.caufield@faa.gov.

SUPPLEMENTARY INFORMATION:

Comments Invited

We invite you to send any written relevant data, views, or arguments about this 

proposed AD. Send your comments to an address listed under the ADDRESSES section.

Include “Docket No. FAA-2015-0486; Directorate Identifier 2015-NE-07-AD” at the

beginning of your comments. We specifically invite comments on the overall regulatory, 

economic, environmental, and energy aspects of this proposed AD. We will consider all 

comments received by the closing date and may amend this proposed AD based on those

comments.

We will post all comments we receive, without change, to 

http://www.regulations.gov, including any personal information you provide. We will 

also post a report summarizing each substantive verbal contact with FAA personnel 

concerning this proposed AD.

Discussion

The Transport Canada Civil Aviation, which is the aviation authority for Canada, 

has issued Canada AD CF-2015-01, dated January 20, 2015 (referred to hereinafter as 

“the MCAI”), to correct an unsafe condition for the specified products. The MCAI states:

Five incidences 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.

3
Repeated over-torque conditions that are undetected and 

consequently 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 safety of the aircraft. 

Investigation by P&WC has determined the root cause of the 

subject torque indication anomaly to be the axial migration of part 

number (P/N) 3310433-03 bearings at the engine torque sensing 

gear location.

The axial migration of the No. 10 bearing is caused by non-optimal bearing 

internal clearance. This migration may cause an erroneous torque reading, possibly 

leading to engine overtorque and engine failure. We are also requiring replacement of the 

No. 9 bearing since it may also migrate, has the same part number as a No. 10 bearing, 

and could be installed in the same location as a No. 10 bearing.

You may obtain further information by examining the MCAI in the AD docket on 

the Internet at http://www.regulations.gov by searching for and locating Docket No. 

FAA-2015-0486.

Related Service Information under 1 CFR Part 51

P&WC has issued Service Bulletin (SB) No. PT6B-72-39095, Revision No. 3, 

dated December 29, 2014. The service information describes procedures for inspecting

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 of this NPRM.

Other Related Service Information

P&WC has also issued SB No. PT6B-72-39092, Revision No. 4, dated December 

29, 2014. The service information describes procedures for removing affected bearings.

4
FAA’s Determination and Requirements of This Proposed AD

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, they have notified us of the unsafe condition described in the MCAI and service 

information referenced above. We are proposing this AD because we evaluated all 

information provided by Transport Canada Civil Aviation and determined the unsafe 

condition exists and is likely to exist or develop on other products of the same type 

design. This proposed AD would require initial and repetitive inspections until 

replacement of the No. 10 bearing, as well as eventual replacement of the No. 9 bearing,

in the engine RGB assembly.

Costs of Compliance

We estimate that this proposed AD affects 83 engines installed on rotorcraft of 

U.S. registry. We estimate that it would take about 3 hours per engine to perform the 

initial and repetitive inspections to comply with this proposed AD. We also estimate that 

it would take about 1 hour per engine to replace the affected bearings. The average labor 

rate is $85 per hour. Required parts cost about $49,800 per engine. Based on these 

figures, we estimate the cost of this proposed AD on U.S. operators to be $4,161,620.

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.

5
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 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) Is not a “significant rule” under the 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.

List of Subjects in 14 CFR Part 39

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

6
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.

§ 39.13 [Amended]

2. The FAA amends § 39.13 by adding the following new airworthiness directive 

(AD):

Pratt & Whitney Canada Corp.: Docket No. FAA-2015-0486; Directorate Identifier

2015-NE-07-AD.

(a) Comments Due Date

We must receive comments by [INSERT DATE 60 DAYS AFTER DATE OF 

PUBLICATION IN THE FEDERAL REGISTER].

(b) Affected ADs

None.

(c) Applicability

This AD applies to Pratt & Whitney Canada Corp. (P&WC) PT6B-37A turboshaft

engines with engine serial numbers identified in Table 1 of paragraph 4, Appendix, in 

P&WC Service Bulletin (SB) No. PT6B-72-39095, Revision No. 3, dated December 29, 

2014.

7
(d) Reason

This AD was prompted by reports of incorrect engine torque for PT6B-37A 

turboshaft engines. We are issuing this AD to prevent axial migration of the No. 10 

bearing in the engine reduction gearbox (RGB) assembly, which could lead to engine 

overtorque, failure of the engine, in-flight shutdown, and loss of the rotorcraft.

(e) Actions and Compliance

Comply with this AD within the compliance times specified, unless already done.

(1) Initial Inspection

(i) Within 50 flight hours (FHs) time in service after the effective date of this AD, 

inspect the No. 10 bearing, part number (P/N) 3310433-03, in the RGB assembly for 

axial movement. Use paragraphs 3.A. to 3.C. in the Accomplishment Instructions in 

P&WC SB No. PT6B-72-39095, Revision No. 3, dated December 29, 2014, to do the 

inspection. If the bearing fails the inspection, replace the No. 9 and No. 10 bearings

before further flight.

(2) Repetitive Inspection

(i) For engines with 500 FHs or less total time since new (TSN), repeat the 

inspection required by paragraph (e)(1) of this AD every 100 FHs time since last 

inspection (TSLI) until 500 hours total TSN, and, thereafter, every 200 FHs TSLI until 

removal.

(ii) For engines with more than 500 FHs total TSN perform the inspection

required by paragraph (e)(1) to this AD within 200 FHs TSLI, and, thereafter, every 200 

FHs TSLI until removal.

8
(3) Removal and Replacement of Affected Bearings

(i) For engine serial numbers (S/Ns) PCE-PU0192, PU0193, PU0201, PU0208, 

PU0209, PU0212, PU0213, PU0214, PU0216, PU0219, and PU0220, remove the No. 9 

and No. 10 bearings, P/N 3310433-03, within 450 FHs or 42 months after the effective 

date of this AD, whichever occurs first, and replace with parts eligible for installation.

(ii) For all engine S/Ns identified in Applicability paragraph (c) of this AD, other 

than those listed in paragraph (e)(3)(i) of this AD, remove the No. 9 and No. 10 bearings,

P/N 3310433-03, and replace with parts eligible for installation within 42 months after 

the effective date of this AD.

(iii) Replacement of the No. 9 and No. 10 bearing, P/N 3310433-03, with the No. 

9 and No. 10 bearing, P/N 3310233-03 or P/N 3310533-03, is terminating action for this 

AD.

(f) Reporting Requirements

You do not have to contact your Local Field Service Representative as discussed 

in paragraph 3.C.(3) of P&WC SB No. PT6B-72-39095, Revision No. 3, dated December 

29, 2014.

(g) Credit for Previous Action

If you previously replaced the No. 9 and No. 10 bearings in accordance with the 

instructions contained in P&WC SB No. PT6B-72-39092, Revision No. 2, dated August 

8, 2014, or earlier revisions, then you have complied with this AD.

9
(h) Alternative Methods of Compliance (AMOCs)

The Manager, Engine Certification Office, FAA, may approve AMOCs for this

AD. Use the procedures found in 14 CFR 39.19 to make your request. You may email 

your request to: ANE-AD-AMOC@faa.gov.

(i) Related Information

(1) For more information about this AD, contact Barbara Caufield, Aerospace 

Engineer, Engine Certification Office, FAA, Engine & Propeller Directorate, 12 New 

England Executive Park, Burlington, MA 01803; phone: 781-238-7146; fax: 

781-238-7199; email: barbara.caufield@faa.gov.

(2) Refer to MCAI Transport Canada AD CF-2015-01, dated January 20, 2015, 

for more information. You may examine the MCAI in the AD docket on the Internet at

http://www.regulations.gov by searching for and locating it in Docket No. FAA-2015-

0486.

(3) P&WC SB No. PT6B-72-39092, Revision No. 4, dated December 29, 2014, 

and SB No. PT6B-72-39095, Revision No. 3, dated December 29, 2014, can be obtained 

from P&WC using the contact information in paragraph (i)(4) of this proposed AD.

(4) For service information identified in this proposed AD, contact Pratt & 

Whitney Canada Corp., 1000 Marie-Victorin, Longueuil, Quebec, Canada, J4G 1A1; 

phone: 800-268-8000; fax: 450-647-2888; Internet: www.pwc.ca.

(5) You may view this service information at the FAA, Engine & Propeller 

Directorate, 12 New England Executive Park, Burlington, MA. For information on the 

availability of this material at the FAA, call 781-238-7125.

10
Issued in Burlington, Massachusetts, on June 10, 2015.

Ann C. Mollica,

Acting Directorate Manager, Engine & Propeller Directorate,

Aircraft Certification Service.

11