[Federal Register Volume 69, Number 38 (Thursday, February 26, 2004)]
[Proposed Rules]
[Pages 8875-8878]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 04-4101]


 ========================================================================
 Proposed Rules
                                                 Federal Register
 ________________________________________________________________________
 
 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.
 
 ========================================================================
 

  Federal Register / Vol. 69, No. 38 / Thursday, February 26, 2004 / 
Proposed Rules  

[[Page 8875]]



DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2003-NE-59-AD]
RIN 2120-AA64


Airworthiness Directives; General Electric Company CT58 and T58 
Series Turboshaft Engines

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

-----------------------------------------------------------------------

SUMMARY: The FAA proposes to adopt a new airworthiness directive (AD) 
for General Electric Company (GE) CT58-140-1, CT58-140-2, and T58-GE-5, 
-10, -100, and -402 series turboshaft engines with certain serial 
numbers (SNs) of stage 1 compressor disks, part number (P/N) 
5001T20P01, installed. This proposed AD would require removing certain 
stage 1 compressor disks from service before reaching a reduced low-
cycle-fatigue (LCF) life limit. This proposed AD results from two 
reports of low blade tip clearances in the compressor. We are proposing 
this AD to prevent LCF cracking and failure of the stage 1 compressor 
disk, an uncontained engine failure, and damage to the helicopter.

DATES: We must receive any comments on this proposed AD by April 26, 
2004.

ADDRESSES: Use one of the following addresses to submit comments on 
this proposed AD:
     By mail: Federal Aviation Administration (FAA), 
New England Region, Office of the Regional Counsel, Attention: Rules 
Docket No. 2003-NE-59-AD, 12 New England Executive Park, Burlington, MA 
01803-5299.
     By fax: (781) 238-7055.
     By e-mail: [email protected]
    You can get the service information identified in this proposed 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, 
email [email protected].
    You may examine the AD docket, by appointment, at the FAA, New 
England Region, Office of the Regional Counsel, 12 New England 
Executive Park, Burlington, MA.

FOR FURTHER INFORMATION CONTACT: Norman Brown, Senior Engineer, Engine 
Certification Office, FAA, Engine and Propeller Directorate, 12 New 
England Executive Park; telephone (781) 238-7181; fax (781) 238-7199.

SUPPLEMENTARY INFORMATION:

Comments Invited

    We invite you to submit any written relevant data, views, or 
arguments regarding this proposal. Send your comments to an address 
listed under ADDRESSES. Include ``AD Docket No. 2003-NE-59-AD'' in the 
subject line of your comments. If you want us to acknowledge receipt of 
your mailed comments, send us a self-addressed, stamped postcard with 
the docket number written on it; we will date-stamp your postcard and 
mail it back to you. We specifically invite comments on the overall 
regulatory, economic, environmental, and energy aspects of the proposed 
AD. If a person contacts us verbally, and that contact relates to a 
substantive part of this proposed AD, we will summarize the contact and 
place the summary in the docket. We will consider all comments received 
by the closing date and may amend the proposed AD in light of those 
comments.
    We are reviewing the writing style we currently use in regulatory 
documents. We are interested in your comments on whether the style of 
this document is clear, and your suggestions to improve the clarity of 
our communications that affect you. You can get more information about 
plain language at http://www.faa.gov/language and http://www.plainlanguage.gov.

Examining the AD Docket

    You may examine the AD Docket (including any comments and service 
information), by appointment, between 8 a.m. and 4:30 p.m., Monday 
through Friday, except Federal holidays. See ADDRESSES for the 
location.

Discussion

    On May 1, 2003, GE informed the FAA that 320 stage 1 compressor 
disks, P/N 5001T20P01, have high-peak stresses. GE has identified the 
affected stage 1 compressor disks by SN. An investigation by GE 
revealed that the tangential positioning of the blade dovetail slot 
resulted in the high-peak stresses. This proposed AD would require 
removing those stage 1 compressor disks, PN 5001T20P01, from service 
before reaching a reduced LCF life limit of 2,100 hours time-since-new 
(TSN) or by December 31, 2008, whichever occurs first. This condition, 
if not corrected, could result in LCF cracking and failure of the stage 
1 compressor disk, an uncontained engine failure, and damage to the 
helicopter.

Relevant Service Information

    We have reviewed and approved the technical contents of GE Alert 
Service Bulletin (ASB) No. CT58 S/B 72-A0196, dated July 24, 2003, that 
describes the procedures for replacing the stage 1 compressor disk.

FAA's Determination and Requirements of the Proposed AD

    We have evaluated all pertinent information and identified an 
unsafe condition that is likely to exist or develop on other products 
of this same type design. Therefore, we are proposing this AD which 
would require removing certain stage 1 compressor disks from service at 
or before reaching a reduced LCF life limit of 2,100 hours TSN or by 
December 31, 2008, whichever occurs first.

Changes to 14 CFR Part 39--Effect on the Proposed AD

    On July 10, 2002, we issued a new version of 14 CFR part 39 (67 FR 
47998, July 22, 2002), which governs the FAA's AD system. This 
regulation now includes material that relates to altered products, 
special flight permits, and alternative methods of compliance. This 
material previously was included in each individual AD. Since this 
material is included in 14 CFR part 39, we will not include it in 
future AD actions.

Interim Action

    These actions are interim actions and we may take further 
rulemaking actions in the future.

Costs of Compliance

    There are about 320 GE CT58-140-1, CT58-140-2, and T58-GE-5, -10, -
100, and -402 series turboshaft engines of

[[Page 8876]]

the affected design in the worldwide fleet. We estimate that 45 engines 
installed on helicopters of U.S. registry would be affected by this 
proposed AD. The proposed action does not impose any additional labor 
costs. A new disk would cost about $7,965 per engine. We estimate that 
the prorated cost of the life reduction would be about $4,181 per 
engine. Based on these figures, we estimate the total cost of the 
proposed AD to U.S. operators to be $188,172.

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); and
    3. Would 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 proposal and 
placed it in the AD Docket. You may get a copy of this summary by 
sending a request to us at the address listed under ADDRESSES. Include 
``AD Docket No. 2003-NE-59-AD'' in your request.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Safety.

The Proposed Amendment

    Accordingly, under the authority delegated to me by the 
Administrator, the Federal Aviation Administration proposes to amend 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. The FAA amends Sec.  39.13 by adding the following new 
airworthiness directive:

General Electric Company: Docket No. 2003-NE-59-AD.

Comments Due Date

    (a) The Federal Aviation Administration (FAA) must receive 
comments on this airworthiness directive (AD) action by April 26, 
2004.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to General Electric Company (GE) CT58-140-1, 
CT58-140-2, and T58-GE-5, -10, -100, and -402 series turboshaft 
engines with stage 1 compressor disks, part number (P/N) 5001T20P01, 
that have a serial number (SN) listed in the following Table 1:

        Table 1.--Stage 1 Compressor Disk SNs Affected By This AD
GATD0PD2
GATH6RWW
GATH7PR0
GATH86K2
GATH8K0P
GATD0PD3
GATH6T00
GATH7PR1
GATH86K3
GATH8K0R
GATD0PD5
GATH6T01
GATH7PR2
GATH86K4
GATH8K0T
GATD0PD6
GATH6T02
GATH7PR3
GATH86K5
GATH8K0W
GATD0PD7
GATH6T03
GATH7PR4
GATH8A5G
GATH8K12
GATD0PD8
GATH6T04
GATH7PR5
GATH8A5H
GATH8K13
GATD0PD9
GATH6T05
GATH7PR6
GATH8A5J
GATH8K14
GATD0PDA
GATH7K4K
GATH7PR7
GATH8A5K
GATH8K15
GATD0PDC
GATH7K4L
GATH7PR8
GATH8A5L
GATH8K16
GATH53GC
GATH7K4M
GATH7PR9
GATH8A5M
GATH8K17
GATH53GD
GATH7K4N
GATH7PRA
GATH8A5N
GATH8K18
GATH53GE
GATH7K4P
GATH7PRC
GATH8A5P
GATH8K19
GATH53GF
GATH7K4R
GATH7PRD
GATH8A5T
GATH8W7H
GATH53GH
GATH7K4T
GATH7PRE
GATH8A5W
GATH8W7J
GATH53GJ
GATH7K5G
GATH7PRF
GATH8A60
GATH8W7L
GATH53GK
GATH7KGH
GATH7PRG
GATH8A61
GATH8W7M
GATH5T70
GATH7KGK
GATH7PRH
GATH8A62
GATH8W7N
GATH5T71
GATH7KGL
GATH7PRJ
GATH8A63
GATH8W7P
GATH5T72
GATH7KGM
GATH7PRK
GATH8A64
GATH8W7R
GATH5T73
GATH7KGN
GATH7PRL
GATH8A66
GATH8W7T
GATH5T74
GATH7KGP
GATH7PRM
GATH8A67
GATH8WD4
GATH5T75
GATH7KGR
GATH7PRN
GATH8A68
GATH8WD5
GATH5T76
GATH7KGT
GATH7PRP
GATH8GRG
GATH8WD6
GATH5T77
GATH7KGW
GATH7PRR
GATH8GRH
GATH8WD7
GATH5T78
GATH7KH0
GATH7PRT
GATH8GRK
GATH8WD8
GATH5T79
GATH7KH1

[[Page 8877]]

 
GATH7PRW
GATH8GRL
GATH8WD9
GATH5T7A
GATH7KH2
GATH7PT0
GATH8GRM
GATH8WDA
GATH5T7C
GATH7LAL
GATH7RTP
GATH8GRN
GATH8WDC
GATH5T7D
GATH7LAM
GATH7RTR
GATH8GRP
GATH8WDD
GATH5T7E
GATH7LAN
GATH7RTT
GATH8GRR
GATH8WDE
GATH5T7F
GATH7LAP
GATH82R8
GATH8GRT
GATH8WDF
GATH5T7G
GATH7LAR
GATH82R9
GATH8GRW
GATH8WDG
GATH5T7H
GATH7LAT
GATH82RA
GATH8GT0
GATH8WDH
GATH6CDL
GATH7LAW
GATH82RD
GATH8GT1
GATH8WDJ
GATH6CDM
GATH7LC0
GATH82RE
GATH8GT3
GATH8WDK
GATH6CDN
GATH7LC1
GATH82RF
GATH8GT5
GATH8WDL
GATH6CDP
GATH7LC2
GATH82RG
GATH8GT7
GATH94R3
GATH6CDR
GATH7LC3
GATH82RH
GATH8GT8
GATH94R4
GATH6CDT
GATH7LC4
GATH82RJ
GATH8HGF
GATH94R6
GATH6CE0
GATH7LC5
GATH82RK
GATH8HGG
GATH94R7
GATH6CE1
GATH7LC6
GATH82RL
GATH8HGH
GATH94R8
GATH6CE2
GATH7LC7
GATH82RM
GATH8HGJ
GATH94R9
GATH6CE3
GATH7LC8
GATH82RN
GATH8HGK
GATH94RA
GATH6CE4
GATH7M8G
GATH82RP
GATH8HGL
GATH94RC
GATH6CE5
GATH7M8H
GATH82RR
GATH8HGM
GATH94RD
GATH6CE6
GATH7M8J
GATH82RT
GATH8HGN
GATH94RE
GATH6CE7
GATH7M8K
GATH82RW
GATH8HGP
GATH94RF
GATH6CE8
GATH7M8L
GATH82T0
GATH8HGR
GATH94RG
GATH6CE9
GATH7M8M
GATH82T1
GATH8HGT
GATH94RJ
GATH6CEA
GATH7M8N
GATH86JD
GATH8HGW
GATH94RK
GATH6CEC
GATH7MLK
GATH86JE
GATH8HH0
GATH94RN
GATH6CED
GATH7MLL
GATH86JF
GATH8HH1
GATH94RP
GATH6CEE
GATH7MLM
GATH86JG
GATH8HH2
GATH94RR
GATH6CEF
GATH7MLN
GATH86JH
GATH8HH3
GATH94RT
GATH6RH8
GATH7MLP
GATH86JJ
GATH8HH4
GATH96HF
GATH6RH9
GATH7MLR
GATH86JK
GATH8HH5
GATH96HG
GATH6RHC
GATH7MLT
GATH86JL
GATH8HH6
GATH96HK
GATH6RHD
GATH7MLW
GATH86JM
GATH8HH7
GATH96HL
GATH6RHE
GATH7MM0
GATH86JN
GATH8K0H
GATH96HM
GATH6RHF
GATH7MM1
GATH86JP
GATH8K0J
GATH96HN
GATH6RHG
GATH7MM2
GATH86JR
GATH8K0K
GATH96HR
GATH6RHH
GATH7MM3
GATH86JT
GATH8K0L
GATH96HT
GATH6RHJ
GATH7PPT
GATH86JW
GATH8K0M
GATH96HW
GATH6RWT
GATH7PPW
GATH86K0
GATH8K0N
GATH96J0
------------------------------------------------------------------------

    These engines are installed on, but not limited to Agusta S.p.A 
AS-61N, AS-61N1, Sikorsky S-61L, S-61N, S-61R, and S-61NM 
helicopters, and the following surplus military helicopters that 
have been certified in accordance with sections 21.25 or 21.27 of 
the Federal Aviation Regulations (14 CFR 21.25 or 21.27): Sikorsky 
S-61D and S-61V, Glacier CH-3E, Siller CH-3E and SH-3A, and Robinson 
Crane CH-3C, CH-3E, HH-3C, HH-3E, and Carson S-61L helicopters.

Unsafe Condition

    (d) This AD results from two reports of low blade tip clearances 
in the compressor. We are issuing this AD to prevent low-cycle-
fatigue (LCF) cracking and failure of the stage 1 compressor disk, 
an uncontained engine failure, and damage to the helicopter.

[[Page 8878]]

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.

Replacement of Stage 1 Compressor Disks

    (f) If you have a stage 1 compressor disk, P/N 5001T20P01, with 
a SN listed in Table 1 of this AD, replace that stage 1 compressor 
disk at or before reaching a reduced LCF life limit of 2,100 hours 
time-since-new (TSN) or by December 31, 2008, whichever occurs 
first. GE Alert Service Bulletin (ASB) No. CT58 S/B 72-A0196, dated 
July 24, 2003, contains information on replacing the stage 1 
compressor disk.
    (g) After the effective date of this AD, do not install any 
stage 1 compressor disk, P/N 5001T20P01, that has a SN listed in 
Table 1 of this AD and has 2,100 hours TSN or more, into any engine.

Alternative Methods of Compliance

    (h) 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.

Material Incorporated by Reference

    (i) None.

Related Information

    (j) GE Alert Service Bulletin (ASB) No. CT58 S/B 72-A0196, dated 
July 24, 2003, pertains to the subject of this AD.

    Issued in Burlington, Massachusetts, on February 17, 2004.
Francis A. Favara,
Acting Manager, Engine and Propeller Directorate, Aircraft 
Certification Service.
[FR Doc. 04-4101 Filed 2-25-04; 8:45 am]
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