[Federal Register Volume 79, Number 191 (Thursday, October 2, 2014)]
[Proposed Rules]
[Pages 59463-59465]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2014-23553]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2011-0961; Directorate Identifier 2011-NE-22-AD]
RIN 2120-AA64


Airworthiness Directives; Rolls-Royce Corporation Turboprop and 
Turboshaft Engines

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: We propose to supersede airworthiness directive (AD) 2012-14-
06, which applies to certain Rolls-Royce Corporation (RRC) 250-C20, -
C20B, and -C20R/2 turboshaft engines. AD 2012-14-06 currently requires 
a one-time visual inspection and fluorescent-penetrant inspection (FPI) 
on certain 3rd-stage and 4th-stage turbine wheels 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 3rd-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 December 1, 
2014.

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: 
royce.com">helicoptercustsupp@rolls-royce.com; Internet: www.rolls-royce.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 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-2011-
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

[[Page 59464]]

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.

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: 
[email protected].

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-2011-0961; 
Directorate Identifier 2011-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 (P/N) 
23065818, and 4th-stage turbine wheel, P/N 23055944, installed. AD 
2012-14-06 requires a one-time visual inspection and FPI on certain 
3rd-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 
4th-stage turbine wheel blades, which could cause engine failure and 
damage to the aircraft.

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 of 3rd-stage and 4th-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 3rd-stage 
and 4th-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 of the 
3rd-stage and 4th-stage turbine wheels based on HSLI. This proposed AD 
would also require visual inspection and FPI of the 3rd-stage and 4th-
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.

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 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.
    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,
    (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

0
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]

0
2. Amend Sec.  39.13 by removing airworthiness directive (AD) 2012-14-
06, Amendment 39-17120 (77 FR 40479, July 10, 2012), and adding the 
following new AD:


[[Page 59465]]


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 December 1, 
2014.

(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-B17, -B17B, 
-B17C, -B17D, -B17E, -B17F, -B17F/1, -B17F/2 turboprop engines; and 
RRC 250-C20, -C20B, -C20F, -C20J, -C20R, -C20R/1,-C20R/2, -C20R/4, -
C20S and -C20W turboshaft engines with 3rd-stage turbine wheel, part 
number (P/N) 23065818, and 4th-stage turbine wheel, P/N 23055944, 
installed.

(d) Unsafe Condition

    This AD was prompted by investigations that revealed that not 
all 3rd-stage and 4th-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 4th-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.
    (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 [deg]F for 10 seconds or more, or 
exceeds 1,700 [deg]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: [email protected].
    (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 46225-1103; phone: 888-255-4766 or 317-230-2720; 
email: royce.com">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 of this material at the 
FAA, call 781-238-7125.

    Issued in Burlington, Massachusetts, on September 23, 2014.
Colleen M. D'Alessandro,
Assistant Directorate Manager, Engine & Propeller Directorate, Aircraft 
Certification Service.
[FR Doc. 2014-23553 Filed 10-1-14; 8:45 am]
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