[Federal Register Volume 65, Number 64 (Monday, April 3, 2000)]
[Proposed Rules]
[Pages 17471-17473]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 00-8134]


=======================================================================
-----------------------------------------------------------------------

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 99-NE-13-AD]
RIN 2120-AA64


Airworthiness Directives; General Electric Company CT58 Series 
Turboshaft Engines

AGENCY: Federal Aviation Administration, DOT.

[[Page 17472]]


ACTION: Notice of proposed rulemaking (NPRM).

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

SUMMARY: This document proposes the adoption of a new airworthiness 
directive that would supersede two existing airworthiness directives 
(AD's), applicable to General Electric Company (GE) CT58 series 
turboshaft engines. The current AD's revised the counting method for 
hours in repetitive heavy-lift (RHL) service and reduced the life limit 
for rotating components. Life-limited rotating components must be 
removed from service in accordance with the multiplying factors and 
retirement lives contained in General Electric Alert Service Bulletin 
(ASB) CT58 A72-162 (CEB-258), dated July 9, 1979. This proposal would 
require applying an additional multiplying factor to life-limited 
rotating parts when the engine is used in heavy lifting operations. 
This proposal is prompted by a review of the current AD's, 69-23-02 and 
79-23-04, and a determination that the requirements of those AD's may 
conflict. This AD would prevent RHL and utility service multiplier 
factors from being applied incorrectly. The actions specified in the 
proposed AD are intended to prevent low-cycle fatigue failure of 
rotating parts that could result in uncontained engine failure and 
damage to the helicopter.

DATES: Comments must be received by June 2, 2000.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), New England Region, Office of the Regional 
Counsel, Attention: Rules Docket No. 99-NE-13-AD, 12 New England 
Executive Park, Burlington, MA 01803-5299. Comments may also be sent 
via the Internet using the following address: ``[email protected]''. 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 GE Aircraft Engines, General Electric Company, 1000 
Western Avenue, Lynn, MA 01910. This information may be examined at the 
FAA, New England Region, Office of the Regional Counsel, 12 New England 
Executive Park, Burlington, MA.

FOR FURTHER INFORMATION CONTACT: Kevin Donovan, Aerospace Engineer, 
Engine Certification Office, FAA, Engine and Propeller Directorate, 12 
New England Executive Park, Burlington, MA 01803-5299; telephone (781) 
238-7743, fax (781) 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 99-NE-13-AD.'' The postcard will be date stamped and 
returned to the commenter.

Availability of NPRM's

    Any person may obtain a copy of this NPRM by submitting a request 
to the FAA, New England Region, Office of the Regional Counsel, 
Attention: Rules Docket No. 99-NE-13-AD, 12 New England Executive Park, 
Burlington, MA 01803-5299.

Discussion

    On November 4, 1969, the Federal Aviation Administration (FAA) 
issued airworthiness directive (AD) 69-23-02, Amendment 39-870 (34FR 
18296, November 15, 1969), to reduce the life limits for stage 2 
compressor rotor disk shafts and to remove from service stage 2 
compressor rotor disk shafts before reaching those reduced life limits. 
That action was prompted by analyses that indicated the need for a 
reduced life-limit for certain life-limited parts when the engine is 
used in repetitive heavy lift (RHL) operations. That condition, if not 
corrected, could result in low-cycle fatigue failure of rotating parts 
that could result in uncontained engine failure and damage to the 
helicopter.
    On December 13, 1979, the Federal Aviation Administration (FAA) 
issued airworthiness directive (AD) 79-23-04, Amendment 39-3610 (44 FR 
72103, December 13, 1979), to require that the life-limits of certain 
life-limited rotating parts be revised based on multiplying factors 
specified in GEAE alert service bulletin (ASB) (CT58) 72-162 CEB 258, 
dated July 9, 1979, for RHL operations. That action was prompted by the 
need for lower life limits for life-limited rotating parts that are 
installed on engines used for RHL operations. That condition, if not 
corrected, could result in low-cycle fatigue failure of rotating parts 
that could result in uncontained engine failure and damage to the 
helicopter.

Events Since the Issuing of AD 69-23-02 and AD 79-23-04

    Since the issuance of those AD's, the FAA has determined that some 
operators may be applying the multiplying factors for RHL operations 
incorrectly because the requirements of AD 79-23-04 apparently conflict 
with the requirements of AD 69-23-02. The requirements contained in AD 
79-23-04 should have superseded the hourly life limits contained in AD 
69-23-02 and should have specified the use of GEAE ASB (CT58) 72-162 
CEB 258 for all CT58 series engines.

Service Information

    The FAA has reviewed and approved the technical contents of GEAE 
ASB (CT58) 72-162 CEB 258, revision 9, dated October 6, 1998, that 
describes procedures for calculating revised cyclic life limits from 
the hourly life limits based on multiplying factors when the engine is 
used in RHL and utility service operation.

Requirements of the Proposed AD

    Since an unsafe condition has been identified that is likely to 
exist or develop on other GEAE CT58 series turboshaft engines of the 
same type design, this AD supersedes AD 69-23-02 and AD 79-23-04 to 
require calculation of life cycles for life-limited rotating parts 
based on multipliers for RHL and utility service operation, and 
replacement of any part that exceeds the revised limits. The actions 
are required to be accomplished in accordance with the service bulletin 
described previously.

Economic Impact

    There are approximately 380 engines of the affected design in the 
worldwide fleet. The FAA estimates that 130

[[Page 17473]]

engines installed on aircraft of U.S. registry would be affected by 
this proposed AD, that it would take approximately 0.25 work hour per 
engine to accomplish the proposed calculations, and that the average 
labor rate is $60 per work hour. Based on these figures, the total cost 
impact of the proposed AD on U.S. operators is estimated to be $1,950.

Regulatory Impact

    This proposed rule does not have federalism implications, as 
defined in Executive Order (EO) No. 13132, because it 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. 
Accordingly, the FAA has not consulted with state authorities prior to 
publication of this proposed rule.
    For the reasons discussed above, I certify that this proposed 
regulation (1) is not a ``significant regulatory action'' under EO No. 
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 removing Amendment 39-1086 (34 FR 
18296, October 15, 1970) and Amendment 39-3610 (44 FR 72103, December 
13, 1979), and by adding a new airworthiness directive,

    GE Aircraft Engines: Docket No. 99-NE-13-AD.
    Applicability: GE Aircraft Engines CT58 series turboshaft engine 
installed on, but not limited to Boeing -Vertol V-107 series, Kaman 
UH-1F series; and Sikorsky CH/HH-3E series, S-61 A/L/N/R series, and 
S-62 series rotorcraft.

    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 thisAD 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 low-cycle fatigue failure of rotating parts that 
could result in uncontained engine failure and damage to the 
helicopter, accomplish the following:

Calculating New Life Limits for Rotating Parts

    (a) Within 50 hours time-in-service (TIS) after the effective 
date of this AD, calculate the new cycles-since-new (CSN) for life-
limited rotating parts in accordance with the Accomplishment 
Instructions, 2.A. through 2.G. of GEAE service bulletin (CT58)72-
162 CEB-258, revision 9, dated October 6, 1998.
    (b) Remove any part from service that exceeds the new caculated 
life limit and replace it with a serviceable part.

Alternative Methods of Compliance

    (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 (ECO). 
Operators shall submit their requests through an appropriate FAA 
Principal Maintenance Inspector, who may add comments and then send 
it to the Manager, ECO.

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

    (d) Special flight permits may be issued in accordance with 
Sec. Sec. 21.197 and 21.199 of the Federal Aviation Regulations (14 
CFR 21.197 and 21.199) to operate the helicopter to a location where 
the requirements of this AD can be accomplished.

    Issued in Burlington, Massachusetts, on March 28, 2000.
David A. Downey,
Assistant Manager, Engine and Propeller Directorate, Aircraft 
Certification Service.
[FR Doc. 00-8134 Filed 3-31-00; 8:45 am]
BILLING CODE 4910-13-P