[4910-13-P]

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

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

39-18282; AD 2015-20-04]

RIN 2120-AA64

Airworthiness Directives; Pratt & Whitney Canada Corp. Turboshaft Engines

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule.

SUMMARY: We are adopting a new airworthiness directive (AD) for certain Pratt & 

Whitney Canada Corp. (P&WC) PT6B-37A turboshaft engines. This AD requires 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 was prompted by reports of incorrect engine torque for PT6B-37A 

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

engine RGB assembly, which could result in engine overtorque, failure of the engine, inflight shutdown, and loss of the rotorcraft.

DATES: This AD becomes effective [INSERT DATE 35 DAYS AFTER DATE OF 

PUBLICATION IN THE FEDERAL REGISTER].

The Director of the Federal Register approved the incorporation by reference of 

certain publications listed in this AD as of [INSERT DATE 35 DAYS AFTER DATE OF 

PUBLICATION IN THE FEDERAL REGISTER].
ADDRESSES: For service information identified in this AD, contact Pratt & Whitney

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

268-8000; fax: 450-647-2888; Web site: http://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. It is also available on the Internet at http://www.regulations.gov by 

searching for and locating Docket No. FAA-2015-0486.

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 

Management Facility 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), the regulatory evaluation, any comments received, and other 

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

Management Facility, 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, 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.

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SUPPLEMENTARY INFORMATION:

Discussion

We issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 by 

adding an AD that would apply to the specified products. The NPRM was published in 

the Federal Register on June 19, 2015 (80 FR 35260). The NPRM proposed 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.

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.

Comments

We gave the public the opportunity to participate in developing this AD. We 

received no comments on the NPRM (80 FR 35260, June 19, 2015).

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Conclusion

We reviewed the available data and determined that air safety and the public 

interest require adopting this AD as proposed.

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 final rule.

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.

Costs of Compliance

We estimate that this AD affects 83 engines installed on rotocraft of U.S. registry. 

We estimate that it will take about 3 hours per engine to comply with this 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 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.

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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 above, I certify this AD:

(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.

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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.

§ 39.13 [Amended]

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

(AD):

2015-20-04 Pratt & Whitney Canada Corp.: Amendment 39-18282; Docket No. FAA2015-0486; Directorate Identifier 2015-NE-07-AD.

(a) Effective Date

This AD becomes effective [INSERT DATE 35 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.

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(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.

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(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.

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(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. 

http://www.regulations.gov/#!docketDetail;D=FAA-2015-0486.

(j) Material Incorporated by Reference

(1) The Director of the Federal Register approved the incorporation by reference 

(IBR) of the service information listed in this paragraph under 5 U.S.C. 552(a) and 1 CFR 

part 51.

(2) You must use this service information as applicable to do the actions required 

by this AD, unless the AD specifies otherwise.

(i) Pratt & Whitney Canada Corp. Service Bulletin (SB) No. PT6B-72-39095, 

Revision No. 3, dated December 29, 2014.

(ii) Reserved.

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(3) For Pratt & Whitney Canada Corp. service information identified in this 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.

(4) You may view this service information at 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.

(5) You may view this service information at the National Archives and Records 

Administration (NARA). For information on the availability of this material at NARA, 

call 202-741-6030, or go to: http://www.archives.gov/federal-register/cfr/ibrlocations.html.

Issued in Burlington, Massachusetts, on September 22, 2015.

Colleen M. D’Alessandro,

Directorate Manager, Engine & Propeller Directorate,

Aircraft Certification Service.

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