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[Federal Register Volume 80, Number 84 (Friday, May 1, 2015)]
[Proposed Rules]
[Pages 24852-24854]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2015-09932]

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2008-0808; Directorate Identifier 2008-NE-18-AD]
RIN 2120-AA64

Airworthiness Directives; General Electric Company CT58 
Turboshaft Engines

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: We propose to supersede airworthiness directives (ADs) 2001-
18-06 and 2008-22-16, which apply to certain General Electric Company 
(GE) CT58 turboshaft engines. ADs 2001-18-06 and 2008-22-16 require 
recalculating the lives of life-limited rotating parts using a 
Repetitive Heavy-Lift (RHL) multiplying factor and removal from service 
of parts that exceed the recalculated cyclic or hourly life limit. This 
proposed AD would consolidate ADs 2001-18-06 and 2008-22-16, and 
further reduce the life capability of certain parts. We are proposing 
this AD to prevent failure of life-limited rotating parts, uncontained 
part release, damage to the engine, and damage to the aircraft.

DATES: We must receive comments on this proposed AD by June 30, 2015.

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 
General Electric Company, GE Aviation, Room 285, One Neumann Way, 
Cincinnati, OH, 45215; phone: 513- 552-3272; email: 
aviation.fleetsupport@ge.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-2008-
0808; 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.

FOR FURTHER INFORMATION CONTACT: Sanjana Murthy, Aerospace Engineer, 
Engine Certification Office, FAA, Engine & Propeller Directorate, 12 
New England Executive Park, Burlington, MA 01803; phone: 781-238-7750; 
fax: 781-238-7199; email: sanjana.murthy@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-2008-0808; 
Directorate Identifier 2008-NE-18-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

[[Page 24853]]

personal information you provide. We will also post a report 
summarizing each substantive verbal contact we receive about this 
proposed AD.

Discussion

    On August 24, 2001, we issued AD 2001-18-06, Amendment 39-12432 (66 
FR 47575, September 13, 2001), (``AD 2001-18-06''), and on October 20, 
2008, we issued AD 2008-22-16, Amendment 39-15712 (73 FR 63629, October 
27, 2008), (``AD 2008-22-16''), for CT58 turboshaft engines. AD 2001-
18-06 requires the use of an RHL multiplying factor in calculating the 
lives of life-limited rotating parts used in RHL missions. AD 2008-22-
16 addressed a shortfall in the life capability of compressor spools 
used in RHL operations. We issued ADs 2001-18-06 and 2008-22-16 to 
prevent cracks in rotating parts that could result in an uncontained 
engine failure, damage to the engine, and damage to the aircraft.

Actions Since ADs 2001-18-06 and 2008-22-16 Were Issued

    Since we issued ADs 2001-18-06 and 2008-22-16, GE updated the life 
limits of compressor spools. GE also updated how to calculate the life 
consumption of compressor spools and of life-limited rotating parts 
flown in Utility operations. This update resulted in generally reduced 
lives for compressor spools and all other life-limited parts used in 
Utility operations. GE published their updated life calculations for 
all life-limited parts in GE Alert Service Bulletin (ASB) No. CT58 S/B 
72-A0162, Revision 16, dated January 7, 2015.

Relevant Service Information Under 1 CFR Part 51

    We reviewed GE ASB No. CT58 S/B 72-A0162, Revision 16, dated 
January 7, 2015. The service information describes procedures for 
calculating life limits for the affected life-limited rotating parts. 
This service information is reasonably available because the interested 
parties have access to it through their normal course of business or 
see ADDRESSES for other ways to access this service information.

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 reduce the life limits of certain compressor 
spools used in all operations and, through imposition of a new lifing 
methodology, increase the life consumption of all rotating parts used 
in Utility operations.

Costs of Compliance

    We estimate that this proposed AD would affect about 60 engines 
installed on aircraft of U.S. registry. The average pro-rated cost of 
the life-limited rotating parts is $20,000. The average labor rate is 
$85 per hour. Based on these figures, we estimate the cost of the 
proposed AD on U.S. operators to be $8,715,000.

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. The FAA amends Sec.  39.13 by:
0
a. Removing airworthiness directives (AD) 2001-18-06; Amendment 39-
12432 (66 FR 47575, September 13, 2001); and AD 2008-22-16, Amendment 
39-15712 (73 FR 63629, October 27, 2008), and
0
b. Adding the following new AD:

General Electric Company: Docket No. FAA-2008-0808; Directorate 
Identifier 2008-NE-18-AD.

(a) Comments Due Date

    The FAA must receive comments on this AD action by June 30, 
2015.

(b) Affected ADs

    This AD replaces AD 2001-18-06, Amendment 39-12432 (66 FR 47575, 
September 13, 2001) and AD 2008-22-16, Amendment 39-15712 (73 FR 
63629, October 27, 2008.

(c) Applicability

    This AD applies to all General Electric Company (GE) CT58-100-2, 
CT58-110-1, CT58-110-2, CT58-140-1, and CT58-140-2 turboshaft 
engines.

(d) Unsafe Condition

    This AD was prompted by recalculation of life for parts 
installed on engines used in Utility operations, and a reduced life 
for compressor spools in all operations. We are issuing this AD to 
prevent failure of life-limited rotating parts, uncontained part 
release, damage to the engine, and damage to the aircraft.

(e) Compliance

    Do the actions required by this AD, unless already done.

(1) Calculating Cyclic Life Consumption

    Re-calculate the cycles-since-new for all compressor spools, and 
for life-limited rotating parts other than compressor spools used in 
Utility operations. Use paragraphs 3.A.(1) and 3.B.(1) in the 
Accomplishment Instructions of GE Alert Service Bulletin (ASB) No. 
CT58 S/B 72-A0162, Revision 16, dated January 7, 2015, to perform 
the calculations.

[[Page 24854]]

(2) Removal of Compressor Spools

    After the effective date of this AD, remove compressor spools, 
part numbers (P/Ns) 5124T94G02, 6010T57G04, 6010T57G07, and 
6010T57G08 from service, before reaching the life limits specified 
in paragraph 4.(1), Appendix A, in GE ASB No. CT58 S/B 72-A0162, 
Revision 16, dated January 7, 2015, as re-calculated per paragraph 
(e)(1) in this AD.

(3) Removal of Rotating Parts Used in Utility Operations Other Than 
Compressor Spools

    After the effective date of this AD, remove from service any 
life-limited rotating part used in Utility operations other than the 
compressor spools with P/Ns listed in paragraph (e)(2) of this AD 
that exceeds its life limit, as re-calculated per paragraph (e)(1) 
in this AD. Use Tables I, II, III, and IV in paragraphs 3.D. through 
3.G. in the Accomplishment Instructions in GE ASB No. CT58 S/B 72-
A0162, Revision 16, dated January 7, 2015, and paragraph 4.(4), 
Appendix A, of this GE ASB, to determine when to remove these parts.

(4) Removal of Rotating Parts Not Used in Utility Operations Other Than 
Compressor Spools

    After the effective date of this AD, remove from service any 
life-limited rotating part not used in Utility operations other than 
the compressor spools with P/Ns listed in paragraph (e)(2) of this 
AD that exceeds its life limits. Use Tables I, II, III, and IV in 
paragraphs 3.D. through 3.G. in the Accomplishment Instructions in 
GE ASB No. CT58 S/B 72-A0162, Revision 16, dated January 7, 2015, 
and paragraph 4.(3), Appendix A of this GE ASB to determine when to 
remove these parts.

(f) 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.

(g) Related Information

    (1) For more information about this AD, contact Sanjana Murthy, 
Aerospace Engineer, Engine Certification Office, FAA, Engine & 
Propeller Directorate, 12 New England Executive Park, Burlington, MA 
01803; phone: 781-238-7750; fax: 781-238-7199; email: 
sanjana.murthy@faa.gov.
    (2) GE ASB No. CT58 S/B 72-A0162, Revision 16, dated January 7, 
2015, can be obtained from GE using the contact information in 
paragraph (g)(3) of this proposed AD.
    (3) For service information identified in this AD, contact 
General Electric Company, GE Aviation, Room 285, One Neumann Way, 
Cincinnati, OH 45215; phone: 513-552-3272; email: 
aviation.fleetsupport@ge.com.
    (4) 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.

    Issued in Burlington, Massachusetts, on April 17, 2015.
Thomas A. Boudreau,
Acting Manager, Engine & Propeller Directorate, Aircraft Certification 
Service.
[FR Doc. 2015-09932 Filed 4-30-15; 8:45 am]
 BILLING CODE 4910-13-P
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