Document ID: FAA-2008-0808-0007
Agency: faa
Document Type: Rule
Title: Airworthiness Directives: General Electric Company Turboshaft Engines
Posted Date: 2015-10-14T04:00Z

[Federal Register Volume 80, Number 198 (Wednesday, October 14, 2015)]
[Rules and Regulations]
[Pages 61720-61722]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2015-25719]

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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; 
Amendment 39-18288; AD 2015-20-09]
RIN 2120-AA64

Airworthiness Directives; General Electric Company Turboshaft 
Engines

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule.

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SUMMARY: We are superseding airworthiness directives (AD) 2001-18-06 
and AD 2008-22-16, for all General Electric Company (GE) CT58 
turboshaft engines. AD 2001-18-06 and AD 2008-22-16 required 
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 
new AD would consolidate AD 2001-18-06 and AD 2008-22-16, and further 
reduce the life capability of certain parts. 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.

DATES: This AD is effective November 18, 2015.
    The Director of the Federal Register approved the incorporation by 
reference of a certain publication listed in this AD as of November 18, 
2015.

ADDRESSES: 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:

[[Page 61721]]

ge.com">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 AD, 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: Christopher McGuire, Aerospace 
Engineer, Engine Certification Office, FAA, Engine & Propeller 
Directorate, 12 New England Executive Park, Burlington, MA 01803; 
phone: 781-238-7120; fax: 781-238-7199; email: chris.mcguire@faa.gov.

SUPPLEMENTARY INFORMATION:

Discussion

    We issued a notice of proposed rulemaking (NPRM) to amend 14 CFR 
part 39 to supersede AD 2001-18-06, Amendment 39-12432 (66 FR 47575, 
September 13, 2001, (``AD 2001-18-06'') and AD 2008-22-16, Amendment 
39-15712 (73 FR 63629, October 27, 2008, (``AD 2008-22-16''). AD 2001-
18-06 and AD 2008-22-16 applied to certain GE CT58 turboshaft engines. 
The NPRM published in the Federal Register on May 1, 2015 (80 FR 
24852). The NPRM was prompted by GE updating the life limits of 
compressor spools. GE also updated the calculation method for 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. The NPRM proposed to consolidate AD 2001-18-06 and 
AD 2008-22-16, and further reduce the life capability of certain parts. 
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.

Related Service Information Under 1 CFR Part 51

    We reviewed GE CT58 Alert Service Bulletin (ASB) No. SB 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.

Comments

    We gave the public the opportunity to participate in developing 
this AD. The following presents the comments received on the NPRM and 
the FAA's response to each comment.

Request New Method for Determining Reduced Life Limits

    AAR Airlift Group (AAR) requested replacement of the current method 
for determining reduced life limits because current limits do not agree 
with operators field experience. AAR independent testing revealed that 
expired critical rotating parts showed no fatigue cracks.
    We disagree. FAA-approved life limits for rotating parts are 
specified to prevent fatigue crack initiation, using conservative 
analytical margins. The number of parts that AAR had inspected would 
not be sufficient to show a likelihood of part cracking consistent with 
FAA regulatory guidelines for rotating part life limits. We did not 
change this AD.

Request Reassessment of Cost Impact

    AAR disagrees that the NPRM has minimal impact on their company. 
AAR stated that their cost per flight would increase and company 
revenue would be reduced.
    We agree that this AD will impose an economic impact to operators. 
How an operator absorbs or passes on the cost is left to the operator 
to determine. We did not change this AD.

Clarification Requirements

    Since we issued the proposed AD, we discovered that ASB formatting 
discrepancies exist due to documentation changes implemented by GE. We 
changed paragraphs (e)(2), (e)(3), and (e)(4) to reflect the correct SB 
paragraph numbers.

Conclusion

    We reviewed the relevant data and determined that air safety and 
the public interest require adopting this AD as proposed.

Costs of Compliance

    We estimate that this AD will 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 this 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 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 that this AD:
    (1) Is not a ``significant regulatory action'' under Executive 
Order 12866,
    (2) Is not a ``significant rule'' under 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.

Adoption of the Amendment

    Accordingly, under the authority delegated to me by the 
Administrator,

[[Page 61722]]

the FAA amends 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) (``AD 2001-18-06''); and AD 
2008-22-16, Amendment 39-15712 (73 FR 63629, October 27, 2008) (``AD 
2008-22-16''), and
0
b. Adding the following new AD:

2015-20-09 General Electric Company: Amendment 39-18288; Docket No. 
FAA-2008-0808; Directorate Identifier 2008-NE-18-AD.

(a) Effective Date

    This AD is effective November 18, 2015.

(b) Affected ADs

    This AD replaces AD 2001-18-06 and AD 2008-22-16.

(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 CT58 Alert Service Bulletin (ASB) 
No. SB 72-A0162, Revision 16, dated January 7, 2015, to perform the 
calculations.

(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.A., Appendix A, in GE CT58 ASB No. SB 72-A0162, 
Revision 16, dated January 7, 2015, as re-calculated per paragraph 
(e)(1) of 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) of this AD. Use Tables I, II, III, and IV in paragraphs 3.D. 
through 3.G. in the Accomplishment Instructions in GE CT58 ASB No. 
SB 72-A0162, Revision 16, dated January 7, 2015, and paragraph 4.D., 
Appendix A of this GE CT58 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 limit. Use Tables I, II, III, and IV 
in paragraphs 3.D. through 3.G. in the Accomplishment Instructions 
in GE CT58 ASB No. SB 72-A0162, Revision 16, dated January 7, 2015, 
and paragraph 4.C., Appendix A of this GE CT58 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

    For more information about this AD, contact Christopher McGuire, 
Aerospace Engineer, Engine Certification Office, FAA, Engine & 
Propeller Directorate, 12 New England Executive Park, Burlington, MA 
01803; phone: 781-238-7120; fax: 781-238-7199; email: 
chris.mcguire@faa.gov.

(h) 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) General Electric Company (GE) CT58 Alert Service Bulletin 
No. SB 72-A0162, Revision 16, dated January 7, 2015.
    (ii) Reserved.
    (3) For GE 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: 
ge.com">aviation.fleetsupport@ge.com.
    (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/ibr-locations.html.

    Issued in Burlington, Massachusetts, on September 30, 2015.
Colleen M. D'Alessandro,
Directorate Manager, Engine & Propeller Directorate, Aircraft 
Certification Service.
[FR Doc. 2015-25719 Filed 10-13-15; 8:45 am]
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