Document ID: FAA-2008-0808-0002
Agency: faa
Document Type: Rule
Title: Airworthiness Directives; General Electric Company (GE) CT58 Series Turboshaft Engines
Posted Date: 2008-10-27T04:00Z

[Federal Register: October 27, 2008 (Volume 73, Number 208)]
[Rules and Regulations]               
[Page 63629-63630]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr27oc08-6]                         

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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 39-15712; AD 2008-22-16]
RIN 2120-AA64

 
Airworthiness Directives; General Electric Company (GE) CT58 
Series Turboshaft Engines

AGENCY: Federal Aviation Administration (FAA), Department of 
Transportation (DOT).

ACTION: Final rule.

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SUMMARY: The FAA is adopting a new airworthiness directive (AD) for 
certain GE CT58 series turboshaft engines. This AD requires 
recalculating the lives of certain part numbered compressor spools 
using a new repetitive heavy lift (RHL) multiplying factor. This AD 
results from reports of cracks originating from the inner faces of the 
locking screw holes in the compressor spool. We are issuing this AD to 
prevent cracks due to RHL missions. Cracks could result in an 
uncontained rotor burst and damage to, or loss of, the helicopter and 
serious injuries to any person onboard.

DATES: This AD becomes effective December 1, 2008.

ADDRESSES: You can get the service information identified in this AD 
from GE Aircraft Engines Customer Support Center, M/D 285, 1 Neumann 
Way, Evendale, OH 45215; telephone (513) 552-3272; fax (513) 552-3329; 
e-mail GEAE.csc@ae.ge.com.
    The Docket Operations office is located at Docket Management 
Facility, U.S. Department of Transportation, 1200 New Jersey Avenue 
SE., West Building Ground Floor, Room W12-140, Washington, DC 20590-
0001.

FOR FURTHER INFORMATION CONTACT: Christopher J. Richards, Aerospace 
Engineer, Engine Certification Office, FAA, Engine & Propeller 
Directorate, 12 New England Executive Park, Burlington, MA 01803; e-
mail: christopher.j.richards@faa.gov; telephone (781) 238-7133; fax 
(781) 238-7199.

SUPPLEMENTARY INFORMATION: The FAA proposed to amend 14 CFR part 39 
with a proposed AD. The proposed AD applies to certain GE CT58 series 
turboshaft engines. We published the proposed AD in the Federal 
Register on July 23, 2008 (73 FR 42724). That action proposed to 
require recalculating the cycles on certain compressor spools using new 
RHL mission multipliers within 30 days after the effective date of the 
proposed AD.

Examining the AD Docket

    You may examine the AD docket on the Internet at http://
www.regulations.gov; or in person at the Docket Operations office 
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 street address for 
the Docket Operations office (telephone (800) 647-5527) is provided in 
the ADDRESSES section. Comments will be available in the AD docket 
shortly after receipt.

Comments

    We provided the public the opportunity to participate in the 
development of this AD. We received no comments on the proposal or on 
the determination of the cost to the public.

Conclusion

    We have carefully reviewed the available data and determined that 
air safety and the public interest require adopting the AD as proposed.

Costs of Compliance

    We estimate that this proposed AD will affect 89 engines installed 
on helicopters of U.S. registry. We also estimate that it will take 
about 0.5 work-hour per engine to perform the proposed actions, and 
that the average labor rate is $80 per work-hour. Prorated life lost 
for the compressor spools will cost about $16,972 per engine. Based on 
these figures, we estimate the total cost of this AD to U.S. operators 
to be $1,514,068.

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); and
    (3) 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.
    We prepared a summary of the costs to comply with this AD and 
placed it in the AD Docket. You may get a copy of this summary at the 
address listed under ADDRESSES.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Safety.

Adoption of the Amendment

0
Accordingly, under the authority delegated to me by the Administrator, 
the Federal Aviation Administration 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 adding the following new airworthiness 
directive:

2008-22-16 General Electric Company (GE): Amendment 39-15712. Docket 
No. FAA-2008-0808; Directorate Identifier 2008-NE-18-AD.

[[Page 63630]]

Effective Date

    (a) This airworthiness directive (AD) becomes effective December 
1, 2008.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to GE CT58 series turboshaft engines with a 
compressor spool, part number (P/N) 5920T82G07, 6010T57G07, or 
6010T57G08, installed. These engines are installed on, but not 
limited to, Sikorsky S-61A, S-61L, S-61N, S-61R, S-62, and Columbia 
107-II helicopters.

Unsafe Condition

    (d) This AD results from reports of cracks originating from the 
inner faces of the locking screw holes in the compressor spool. We 
are issuing this AD to prevent cracks due to repetitive heavy lift 
(RHL) missions. Cracks could result in an uncontained rotor burst 
and damage to, or loss of, the helicopter and serious injuries to 
any person onboard.

Compliance

    (e) You are responsible for having the actions required by this 
AD performed within the compliance times specified unless the 
actions have already been done.

Recalculating Compressor Spool Cycles

    (f) Within 30 days after the effective date of this AD, 
recalculate the life of compressor spools, P/N 5920T82G07, 
6010T57G07, or 6010T57G08, using an RHL mission multiplying factor 
of both 3.7 cycles per hour and 6.0 cycles per hour. GE Alert 
Service Bulletin CT58 S/B 72-A0162, Revision 12, dated April 17, 
2008, contains information on calculating life cycles for the 
compressor spools.

Removing Compressor Spools Based on the New Recalculated Cycles

    (g) Before January 1, 2010, remove the compressor spools, P/N 
5920T82G07, 6010T57G07, or 6010T57G08, at the earlier of when:
    (1) The compressor spool reaches its part life limit as 
calculated using an RHL multiplying factor of 3.7, or
    (2) You can see the spool at shop visit after it has reached its 
part life limit using an RHL multiplying factor of 6.0.
    (h) On January 1, 2010 and thereafter, remove the engine before 
the compressor spool exceeds its part life limit as calculated using 
an RHL multiplying factor of 6.0.
    (i) As of January 1, 2010, don't use an RHL multiplying factor 
of 3.7 to calculate the life of the compressor spool.

Installation Prohibition

    (j) After the effective date of this AD, don't install any 
engine that has a compressor spool installed that meets or exceeds 
the life limits as calculated in paragraph (g)(1) through (g)(2) or 
(h) of this AD.

Alternative Methods of Compliance

    (k) The Manager, Engine Certification Office, has the authority 
to approve alternative methods of compliance for this AD if 
requested using the procedures found in 14 CFR 39.19.

Related Information

    (l) GE Alert Service Bulletin CT58 S/B 72-A0162, Revision 12, 
dated April 17, 2008, pertains to the subject of this AD.
    (m) Contact Christopher J. Richards, Aerospace Engineer, Engine 
Certification Office, FAA, Engine & Propeller Directorate, 12 New 
England Executive Park, Burlington, MA 01803; e-mail: 
christopher.j.richards@faa.gov; telephone (781) 238-7133; fax (781) 
238-7199, for more information about this AD.

Material Incorporated by Reference

    (n) None.

    Issued in Burlington, Massachusetts, on October 20, 2008.
Peter A. White,
Assistant Manager, Engine and Propeller Directorate, Aircraft 
Certification Service.
[FR Doc. E8-25442 Filed 10-24-08; 8:45 am]

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