DEPARTMENT OF TRANSPORTATION 

Federal Aviation Administration 

14 CFR Part 39 

[Docket No. FAA-2011-0961; Directorate Identifier 2011-NE-22-AD] 

RIN 2120-AA64 

[4910-13-P] 

Airworthiness Directives; Rolls-Royce Corporation Turboprop and Turboshaft 

Engines 

AGENCY: Federal Aviation Administration (FAA), DOT. 

ACTION: Notice of proposed rulemaking (NPRM). 

SUMMARY: We propose to supersede airworthiness directive (AD) 2012-14-06, which 

applies to certain Rolls-Royce Corporation (RRC) 250-C20, -C20B, and - C20RJ2 

turbo shaft engines. AD 2012-14-06 currently requires a one-time visual inspection and 

fluorescent-penetrant inspection (FPI) on certain 3rct_stage and 41

h-stage turbine whee ls 

for cracks in the turbine blades. Since we issued AD 2012-14-06, we determined that the 

one-time inspection required by AD 2012-14-06 should be changed to repetitive 

inspections and that we should add an inspection after any engine hot start. We also 

identified additional engine models subject to the unsafe condition. This proposed AD 

would replace the one-time visual inspection and FPI with repetitive visual inspections 

and FPis, and would also require inspection and FPI after any engine hot start. This 

proposed AD would also add certain engine models to the applicability. We are 

proposing this AD to prevent failure of 3 rct -stage and 4th -stage turbine wheel blades, 

which could cause engine failure and damage to the aircraft. 

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, using the procedures found in 14 CFR 11.43 

and 11.45, by any of the following methods: 

• Federal eRulemaking Portal: Go to http://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 proposed AD, contact Rolls-Royce 

Corporation, 450 South Meridian Street, Indianapolis, IN 46225-1103; phone: 888-255-

4766 or 317-230-2720; email: helicoptercustsupp@rolls-royce.com; Internet: www.rollsroyce.com. You may view this service information at the FAA, Engine & Propeller 

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

availability ofthis 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. F AA-20 11-0961 ; 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 proposed AD, the regulatory evaluation, any 

comments received, and other information. The street 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. 

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FOR FURTHER INFORMATION CONTACT: John Tallarovic, Aerospace Engineer, 

Chicago Aircraft Certification Office, FAA, 2300 E. Devon Ave. , Des Plaines, IL 60018 ; 

phone: 847-294-8180; fax: 847-294-7834; email: john.m.tallarovic@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. F AA-20 11-0961; Directorate Identifier 20 11-NE-22-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 because of 

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 we receive about this 

proposed AD. 

Discussion 

On June 25, 2012, we issued AD 2012-14-06, Amendment 39-17120 (77 FR 

40479, July 10, 2012), for certain RRC 250-C20, -C20B, and -C20R/2 turboshaft engines 

with 3rd -stage turbine wheel, part number (PIN) 23065818, and 4111 -stage turbine wheel, 

PIN 23055944, installed. AD 2012-14-06 requires a one-time visual inspection and FPl 

on certain 3 rd -stage and 4th -stage turbine wheels for cracks in the turbine blades. AD 

2012-14-06 resulted from seven cases of released turbine blades and shrouds, which led 

to loss of power and engine in-flight shutdowns. We issued AD 2012-14-06 to prevent 

failure of 3rd -stage and 4111 -stage turbine wheel blades, which could cause engine failure 

and damage to the aircraft. 

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Actions Since AD 2012-14-06 Was Issued 

Since we issued AD 2012-14-06, Amendment 39-17120 (77 FR 40479, July 10, 

2012), investigations ofYd-stage and 4111 -stage turbine wheel blade failures found that the 

one-time inspection required by that AD was not identifying all failures. We determined 

that repetitive inspections, triggered by hours since last inspection (HSLI) or any hot start 

event, are required to address the unsafe condition. We also identified additional engine 

models that are subject to the unsafe condition, and have added those engine models to 

the applicability of this AD. 

Relevant Service Information 

We reviewed RRC Alert Commercial Engine Bulletin (CEB) No. CEB-A-1407, 

Revision 3, dated May 19,2014, and CEB No. CEB-A-72-4098, Revision 3, dated May 

19, 2014 (combined into one document). The service information describes procedures 

for inspecting the 3 rd -stage and 4111 -stage turbine wheels. 

FAA's Determination 

We are proposing this AD because we evaluated all the relevant information 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 retain the initial inspection requirements of AD 2012-

14-06, Amendment 39-17120 (77 FR 40479, July 10, 2012). This proposed AD would 

require repetitive visual inspections and FPis ofthe 3rd_stage and 4111 -stage turbine wheels 

based on HSLI. This proposed AD would also require visual inspection and FPI of the 

3rd -stage and 4111 -stage turbine wheels whenever an engine hot start occurs. We have 

added the requirement for opportunity inspections when the turbine is already 

disassembled because of the repetitive nature of this inspection. This proposed AD would 

also expand the applicability of this AD to include additional engine models. 

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Costs of Compliance 

We estimate that this proposed AD affects 3,769 engines installed on aircraft of 

U.S. registry. We also estimate that it would take about 1 hour per engine to comply with 

the recurring inspection requirement of this AD. We estimate that about 19 engines will 

require an inspection following a hot start, and that it would take about 27 hours per 

engine to perform that inspection. The average labor rate is $85 per hour. Based on these 

figures, we estimate the cost of this proposed AD on U.S. operators to be $363 ,970. 

Authority for this Rulemaking 

Title 49 ofthe 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. 

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 have 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 that the proposed regulation: 

( 1) Is not a "significant regulatory action" under Executive Order 12866, 

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(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. 

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 removing airworthiness directive (AD) 201 2-1 4-

06, Amendment 39-17120 (77 FR 40479, July 10, 2012), and adding the followin g new 

AD: 

Rolls-Royce Corporation (Type Certificate previously held by Allison Engine 

Company and Allison Gas Turbine Division of General Motors): Docket 

No. FAA-2011-0961 ; Directorate Identifier 2011-NE-22-AD. 

(a) Comments Due Date 

The FAA must receive.comments on this AD action by [INSERT DATE 60 

DAYS AFTER DATE OF PUBLICATION IN THE FEDERAL REGISTER]. 

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(b) Affected ADs 

This AD supersedes AD 2012-14-06, Amendment 39-17120 (77 FR 40479, July 

10, 2012). 

(c) Applicability 

This AD applies to Rolls-Royce Corporation (RRC) 250-B 17, -B 178, -B 17C, 

-B 17D, -B 17E, -B 17F, -B 17Fil , -B 17F/2 turboprop engines; and RRC 250-C20, -C20B, 

-C20F, -C20J, -C20R, -C20R/l ,-C20R/2, -C20R/4, -C20S and -C20W turboshaft engines 

with yct -stage turbine wheel, part number (PIN) 23065818, and 41

h -stage turbine wheel, 

PIN 23055944, installed. 

(d) Unsafe Condition 

This AD was prompted by investigations that revealed that not all 3 rd -stage and 

4111 -stage turbine wheel blade failures were identified by the one-time inspections required 

by AD 2012-14-06, Amendment 39-17120 (77 FR 40479, July 10, 2012). We determined 

that to address the unsafe condition, repetitive inspections are required, triggered by 

hours since last inspection (HSLI) or any hot start event. We are issuing this AD to 

prevent failure of 3rd -stage and 41

h-stage turbine wheel blades, which could cause engine 

failure and damage to the aircraft. 

(e) Compliance 

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

After the effective date of this AD: 

(1) Within 1,750 HSLI, remove the affected turbine wheels and perform a visual 

inspection and a fluorescent-penetrant inspection (FPI) on the removed turbine wheels for 

cracks at the trailing edge of the turbine blades near the fillet at the rim. 

(2) Any time there is a hot start, immediately perform a visual inspection and an 

FPI on the affected turbine wheels for cracks at the trailing edge of the turbine blades, 

near the fillet at the rim. 

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(3) Any time the power turbine is disassembled, perform a visual inspection and 

an FPI on the affected turbine wheels for cracks at the trailing edge of the turbine blades, 

near the fillet at the rim. 

(4) Thereafter, re-inspect every 1,750 HSLI. 

(5) Do not return to service any turbine wheels that have cracks detected. 

(f) Definition 

For the purpose of this AD, an engine hot start is any time the turbine temperature 

exceeds 1,490 °F for 10 seconds or more, or exceeds 1,700 °F for any duration. 

(g) Alternative Methods of Compliance (AMOCs) 

The Manager, Chicago Aircraft Certification Office, may approve AMOCs for 

this AD. Use the procedures found in 14 CFR 39.19 to make your request. 

(h) Related Information 

(1) For more information about this AD, contact John Tallarovic, Aerospace 

Engineer, Chicago Aircraft Certification Office, FAA, 2300 E. Devon Ave., Des Plaines, 

IL 60018; phone: 847-294-8180; fax: 847-294-7834; email:john.m.tallarovic@faa.gov . 

(2) RRC Alert Commercial Engine Bulletin (CEB) No. CEB-A-1407, Revision 3, 

dated May 19,2014, and CEB No. CEB-A-72-4098, Revision 3, dated May 19,2014 

(combined into one document), which are not incorporated by reference in this AD, can 

be obtained from RRC, using the contact information in paragraph (h)(3) of this AD. 

(3) For service information identified in this AD, contact Rolls-Royce 

Corporation Customer Support, 450 South Meridian Street, Indianapolis, IN 46225-11 03 ; 

phone: 888-255-4766 or 317-230-2720; email: helicoptercustsupp@rolls-royce.com; 

Internet: www.rolls-royce.com. 

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

Directorate, 12 New England Executive Park, Burlington, MA 01803 . For information on 

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

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Issued in Burlington, Massachusetts, on September 23 , 2014. 

Colleen M. D' Alessandro, 

Assistant Directorate Manager, Engine & Propeller Directorate, 

Aircraft Certification Service. 

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