[Federal Register Volume 62, Number 110 (Monday, June 9, 1997)]
[Proposed Rules]
[Pages 31370-31371]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 97-14957]
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Proposed Rules
Federal Register
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This section of the FEDERAL REGISTER contains notices to the public of
the proposed issuance of rules and regulations. The purpose of these
notices is to give interested persons an opportunity to participate in
the rule making prior to the adoption of the final rules.
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Federal Register / Vol. 62, No. 110 / Monday, June 9, 1997 / Proposed
Rules
[[Page 31370]]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 97-ANE-18-AD]
RIN 2120-AA64
Airworthiness Directives; General Electric Company CT58 Series
Turboshaft Engines
AGENCY: Federal Aviation Administration, DOT.
ACTION: Notice of proposed rulemaking (NPRM).
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SUMMARY: This document proposes the adoption of a new airworthiness
directive (AD) that is applicable to General Electric Company CT58
series turboshaft engines. This proposal would require removal from
service of certain stage 1 and 2 forward cooling plates, and stage 2
aft cooling plates, and replacement with serviceable parts. This
proposal is prompted by reports of certain cooling plates forged with
contaminated alloy that could reduce the lives of the parts. The
actions specified by the proposed AD are intended to prevent cooling
plate fracture, which could result in a contained engine failure, and
an inflight engine shutdown.
DATES: Comments must be received by August 8, 1997.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), New England Region, Office of the Assistant Chief
Counsel, Attention: Rules Docket No. 97-ANE-18-AD, 12 New England
Executive Park, Burlington, MA 01803-5299. Comments may also be sent
via the Internet using the following address: ``engineprop@faa.dot.gov''. Comments sent via the Internet must contain
the docket number in the subject line. Comments may be inspected at
this location between 8:00 a.m. and 4:30 p.m., Monday through Friday,
except Federal holidays.
The service information referenced in the proposed rule may be
obtained from General Electric Company (GE), 1000 Western Ave., Lynn,
MA 01909; telephone (671) 594-9894, fax (617) 594-1527. This
information may be examined at the FAA, New England Region, Office of
the Assistant Chief Counsel, 12 New England Executive Park, Burlington,
MA.
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 (617) 238-
7134, fax (617) 238-7199.
SUPPLEMENTARY INFORMATION:
Comments Invited
Interested persons are invited to participate in the making of the
proposed rule by submitting such written data, views, or arguments as
they may desire. Communications should identify the Rules Docket number
and be submitted in triplicate to the address specified above. All
communications received on or before the closing date for comments,
specified above, will be considered before taking action on the
proposed rule. The proposals contained in this notice may be changed in
light of the comments received.
Comments are specifically invited on the overall regulatory,
economic, environmental, and energy aspects of the proposed rule. All
comments submitted will be available, both before and after the closing
date for comments, in the Rules Docket for examination by interested
persons. A report summarizing each FAA-public contact concerned with
the substance of this proposal will be filed in the Rules Docket.
Commenters wishing the FAA to acknowledge receipt of their comments
submitted in response to this notice must submit a self-addressed,
stamped postcard on which the following statement is made: ``Comments
to Docket Number 97-ANE-18-AD.'' The postcard will be date stamped and
returned to the commenter.
Availability of NPRMs
Any person may obtain a copy of this NPRM by submitting a request
to the FAA, New England Region, Office of the Assistant Chief Counsel,
Attention: Rules Docket No. 97-ANE-18-AD, 12 New England Executive
Park, Burlington, MA 01803-5299.
Discussion
The Federal Aviation Administration (FAA) has received reports of
certain stage 1 and stage 2 forward cooling plates and stage 2 aft
cooling plates, installed on General Electric Company (GE) Models CT58-
110-1, -110-2, -140-1, -140-2, and T58-GE-3/-5/-8F/-10/-100 turboshaft
engines, forged with contaminated alloy that could reduce the lives of
the parts. Iron-rich inclusions were found in forgings produced by a
vendor using A286 material. These inclusions were first found on parts
from two heat lots during the normal Vacuum Induction Melt (VIM) in-
process macroetch inspections. The parts from these two heat lots were
then scrapped. Corrective actions to the VIM process were implemented
to prevent the reoccurrence of iron-rich inclusions. Records of all
heat lots produced from this vendor prior to the implementation of the
corrective actions, totaling 56 heat lots, were reviewed. Twenty five
out of the 56 heat lots were determined to be potentially contaminated.
Approximately 300 GE CT58 cooling plates were produced from one
potentially contaminated heat lot. A retired cooling plate from this
suspected heat lot was macroetch inspected and was found with an
inclusion. This condition, if not corrected, could result in cooling
plate fracture, which could result in a contained engine failure, and
an inflight engine shutdown.
The FAA has reviewed and approved the technical contents of GE
Aircraft Engines CT58 Service Bulletin (SB) No. 72-188 (CEB-293), dated
March 25, 1997, that describes procedures for removal from service of
certain stage 1 and 2 forward cooling plates, and stage 2 aft cooling
plates, and replacement with serviceable parts.
Since an unsafe condition has been identified that is likely to
exist or develop on other products of this same type design, the
proposed AD would require removal from service of certain stage 1 and 2
forward cooling plates, and stage 2 aft cooling plates, and replacement
with serviceable parts. The actions would be required to be
accomplished in accordance with the SB described previously.
[[Page 31371]]
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 would be affected by this proposed AD, and
that it would not take any additional work hours per engine to
accomplish the proposed actions at next part exposure. Required parts
would cost approximately $2,730 per engine, based on the estimated
current part cost. Based on these figures, the total cost impact of the
proposed 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 proposed herein would 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
proposal would not have sufficient federalism implications to warrant
the preparation of a Federalism Assessment.
For the reasons discussed above, I certify that this 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);
and (3) if promulgated, 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 copy of the draft
regulatory evaluation prepared for this action is contained in the
Rules Docket. A copy of it may be obtained by contacting the Rules
Docket at the location provided under the caption ADDRESSES.
List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation safety, Safety.
The Proposed Amendment
Accordingly, pursuant to the authority delegated to me by the
Administrator, the Federal Aviation Administration proposes to amend
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:
General Electric Company: Docket No. 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 (b) 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), dated March 25, 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.
Issued in Burlington, Massachusetts, on May 27, 1997.
Jay J. Pardee,
Manager, Engine and Propeller Directorate, Aircraft Certification
Service.
[FR Doc. 97-14957 Filed 6-6-97; 8:45 am]
BILLING CODE 4910-13-U
