Airworthiness Directives; General Electric Company CT58 Series Turboshaft Engines

[Federal Register Volume 62, Number 202 (Monday, October 20, 1997)]
[Rules and Regulations]
[Pages 54373-54374]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 97-27351]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 97-ANE-18-AD; Amendment 39-10161; AD 97-21-08]
RIN 2120-AA64


Airworthiness Directives; General Electric Company CT58 Series 
Turboshaft Engines

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule.

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SUMMARY: This amendment adopts a new airworthiness directive (AD), 
applicable to General Electric Company CT58 series turboshaft engines, 
that requires removal from service of certain stage 1 and 2 forward 
cooling plates, and stage 2 aft cooling plates, and replacement with 
serviceable parts. This amendment is prompted by reports of certain 
cooling plates forged with contaminated alloy that could reduce the 
lives of the parts. The actions specified by this AD are intended to 
prevent cooling plate fracture, which could result in a contained 
engine failure, and an inflight engine shutdown.

DATES: Effective December 19, 1997.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of December 19, 1997.

ADDRESSES: The service information referenced in this AD may be 
obtained from General Electric Company (GE), 1000 Western Ave., Lynn, 
MA 01909; telephone (781) 594-9894, fax (781) 594-1527. This 
information may be examined at the Federal Aviation Administration 
(FAA), New England Region, Office of the Assistant Chief Counsel, 12 
New England Executive Park, Burlington, MA; or at the Office of the 
Federal Register, 800 North Capitol Street, NW., suite 700, Washington, 
DC.

FOR FURTHER INFORMATION CONTACT: Diane Cook, Aerospace Engineer, Engine 
Certification Office, FAA, Engine and Propeller Directorate, 12 New 
England Executive Park, Burlington, MA 01803-5299; telephone (781) 238-
7133, fax (781) 238-7199.

SUPPLEMENTARY INFORMATION: A proposal to amend part 39 of the Federal 
Aviation Regulations (14 CFR part 39) to include an airworthiness 
directive (AD) that is applicable to General Electric Company (GE) 
Models CT58-110-1, -110-2, -140-1, -140-2, and T58-GE-3/-5/-8F/-10/-100 
turboshaft engines was published in the Federal Register on June 9, 
1997 (62 FR 31370). That action proposed to require removal from 
service of certain stage 1 and 2 forward cooling plates, and stage 2 
aft cooling plates, and replacement with serviceable parts.
    Interested persons have been afforded an opportunity to participate 
in the making of this amendment. No comments were received on the 
proposal or the FAA's determination of the cost to the public.
    Since publication of the proposed rule, GE Aircraft Engines has 
issued GE Aircraft Engines CT58 Service Bulletin (SB) No. 72-188 (CEB-
293), Revision 1, dated July 15, 1997. This final rule references this 
current revision.
    The FAA has determined that air safety and the public interest 
require the adoption of the rule with the changes described previously.

[[Page 54374]]

    There are approximately 400 engines of the affected design in the 
worldwide fleet. The FAA estimates that 126 engines installed on 
aircraft of U.S. registry will be affected by this AD, that it will not 
take any additional work hours per engine to accomplish the required 
actions at next part exposure. Required parts will cost approximately 
$2,730 per engine. Based on these figures, the total cost impact of the 
AD on U.S. operators is estimated to be $343,980. The manufacturer, 
however, has advised the FAA of a program to prorate the cost of 
required parts downward by a factor equal to the quotient of the 
difference between the original life limit of 4,000 hours time in 
service and the total cycles of life consumed at time of removal, 
divided by the original life limit. Therefore, the actual cost to 
operators may be less than the FAA's estimate.
    The regulations adopted herein will not have substantial direct 
effects 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. Therefore, in 
accordance with Executive Order 12612, it is determined that this final 
rule does not have sufficient federalism implications to warrant the 
preparation of a Federalism Assessment.
    For the reasons discussed above, I certify that this action (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. A final evaluation has been prepared for this action 
and it is contained in the rules docket. A copy of it may be obtained 
from the rules docket at the location provided under the caption 
ADDRESSES.

List of Subjects in 14 CFR Part 39

    Air Transportation, Aircraft, Aviation safety, Incorporation by 
reference, Safety.

Adoption of the Amendment

    Accordingly, pursuant to the authority delegated to me by the 
Administrator, the Federal Aviation Administration amends part 39 of 
the Federal Aviation Regulations (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.


Sec. 39.13  [Amended]

    2. Section 39.13 is amended by adding the following new 
airworthiness directive:

97-21-08 General Electric Company: Amendment 39-10161. Docket 97-
ANE-18-AD.

    Applicability: General Electric Company (GE) Models CT58-110-1, 
-110-2, -140-1, and -140-2, and T58-GE-3/-5/-8F/-10/-100 series 
turboshaft engines, with stage 1 forward cooling plate, Part Number 
(P/N) 37C300055P101, stage 2 forward cooling plate, P/N 3000T88P02, 
and stage 2 aft cooling plate, P/N 3002T27P01, installed. These 
engines are installed on but not limited to Boeing Vertol 107 
series, and Sikorsky S61 and S62 series aircraft.

    Note 1: This airworthiness directive (AD) applies to each engine 
identified in the preceding applicability provision, regardless of 
whether it has been modified, altered, or repaired in the area 
subject to the requirements of this AD. For engines that have been 
modified, altered, or repaired so that the performance of the 
requirements of this AD is affected, the owner/operator must request 
approval for an alternative method of compliance in accordance with 
paragraph (c) of this AD. The request should include an assessment 
of the effect of the modification, alteration, or repair on the 
unsafe condition addressed by this AD; and, if the unsafe condition 
has not been eliminated, the request should include specific 
proposed actions to address it.

    Compliance: Required as indicated, unless accomplished 
previously.
    To prevent cooling plate fracture, which could result in a 
contained engine failure and an inflight engine shutdown, accomplish 
the following:
    (a) Remove from service affected cooling plates, listed by 
serial number in GE Aircraft Engines CT58 Service Bulletin (SB) No. 
72-188 (CEB-293), Revision 1, dated July 15, 1997, and replace with 
serviceable parts, at the next part exposure, or next light 
overhaul, whichever occurs first, but not to exceed 1,000 hours time 
in service (TIS) for engines installed on aircraft that have engaged 
in Repetitive Heavy Lift (RHL) operations, or 2,000 hours TIS for 
engines installed on aircraft that have never engaged in RHL 
operations, in accordance with that SB.
    (b) For the purpose of this AD, the following definitions apply:
    (1) RHL operation is defined as performing more than 10 lift-
carry-drop cycles per hour TIS without landing, or more than 10 
takeoffs and landings per hour TIS.
    (2) Light overhaul is defined as scheduled engine maintenance 
that allows the engine to continue in service until scheduled major 
overhaul time is reached.
    (c) An alternative method of compliance or adjustment of the 
compliance time that provides an acceptable level of safety may be 
used if approved by the Manager, Engine Certification Office. The 
request shall be forwarded through an appropriate FAA Principal 
Maintenance Inspector, who may add comments and then send it to the 
Manager, Engine Certification Office.

    Note 2: Information concerning the existence of approved 
alternative methods of compliance with this airworthiness directive, 
if any, may be obtained from the Engine Certification Office.

    (d) Special flight permits may be issued in accordance with 
sections 21.197 and 21.199 of the Federal Aviation Regulations (14 
CFR 21.197 and 21.199) to operate the aircraft to a location where 
the requirements of this AD can be accomplished.
    (e) The actions required by this AD shall be done in accordance 
with the following GE Aircraft Engines SB:

------------------------------------------------------------------------
          Document No             Pages   Revision          Date        
------------------------------------------------------------------------
72-188 (CEB-293)...............     1-7          1  July 15, 1997       
Total Pages: 7.                                                         
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    This incorporation by reference was approved by the Director of 
the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR 
part 51. Copies may be obtained from General Electric Company (GE), 
1000 Western Ave., Lynn, MA 01909; telephone (781) 594-9894, fax 
(781) 594-1527. Copies may be inspected at the FAA, New England 
Region, Office of the Assistant Chief Counsel, 12 New England 
Executive Park, Burlington, MA; or at the Office of the Federal 
Register, 800 North Capitol Street NW., suite 700, Washington, DC.
    (f) This amendment becomes effective on December 19, 1997.

    Issued in Burlington, Massachusetts, on October 8, 1997.
Jay J. Pardee,
Manager, Engine and Propeller Directorate, Aircraft Certification 
Service.
[FR Doc. 97-27351 Filed 10-17-97; 8:45 am]
BILLING CODE 4910-13-U

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