[Federal Register Volume 64, Number 194 (Thursday, October 7, 1999)]
[Proposed Rules]
[Pages 54587-54589]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-26209]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 98-ANE-41-AD]
RIN 2120-AA64
Airworthiness Directives; General Electric Company CF6-6, CF6-45,
and CF6-50 Series Turbofan Engines
AGENCY: Federal Aviation Administration, DOT.
ACTION: Notice of proposed rulemaking (NPRM).
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SUMMARY: This document proposes the supersedure of an existing
airworthiness directive (AD), applicable to General Electric Company
(GE) CF6-6, CF6-45, and CF6-50 series turbofan engines, that currently
requires revisions to the Time Limits Section of the manufacturer's
Instructions for Continued Airworthiness (ICA) to include required
enhanced inspection of selected critical life-limited parts at each
piece-part exposure. This action would add additional disk bore eddy
current inspections (ECI) for the high pressure turbine rotor (HPTR)
Stage 1 and 2 disks. This proposal is prompted by additional focused
inspection procedures that have been developed by the manufacturer. The
actions specified by this proposed AD are intended to prevent critical
life-limited rotating engine part failure, which could result in an
uncontained engine failure and damage to the airplane.
DATES: Comments must be received by December 6, 1999.
ADDRESSES: Submit comments to the Federal Aviation Administration
(FAA), New England Region, Office of the Regional Counsel, Attention:
Rules Docket No. 98-ANE-41-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.
FOR FURTHER INFORMATION CONTACT: Karen Curtis, Aerospace Engineer,
Engine Certification Office, FAA, Engine and Propeller Directorate, 12
New England Executive Park, Burlington, MA 01803-5299; telephone (781)
238-7192, 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 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 98-ANE-41-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
[[Page 54588]]
FAA, New England Region, Office of the Regional Counsel, Attention:
Rules Docket No. 98-ANE-41-AD, 12 New England Executive Park,
Burlington, MA 01803-5299.
Discussion
On April 2, 1999, the Federal Aviation Administration (FAA) issued
airworthiness directive (AD) 99-08-18, Amendment 39-11124 (64 FR 17958,
April 13, 1999), to require revisions to the Time Limits Section of the
manufacturer's Instructions for Continued Airworthiness (ICA) for
General Electric Company (GE) CF6-6, CF6-45, and CF6-50 series turbofan
engines to include required enhanced inspection of selected critical
life-limited parts at each piece-part exposure.
New Inspection Procedures
Since the issuance of that AD, GE has developed additional focused
inspection procedures. This proposal would add disk bore eddy current
inspections (ECI) for the high pressure turbine rotor (HPTR) Stage 1
and 2 disks.
Proposed Actions
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 supersede AD 99-08-18 to add disk bore ECI for the
HPTR Stage 1 and 2 disks at each piece-part opportunity.
Economic Analysis
The FAA estimates that 730 engines installed on airplanes of U.S.
registry would be affected by this proposed AD, that it would take
approximately 4 work hours per engine to accomplish the proposed new
inspections, and that the average labor rate is $60 per work hour for a
total approximate cost of $240 per engine. The FAA estimates that
approximately 170 HPTR Stage 1 and 2 disks would be exposed to the
piece-part level per year; therefore, the total annual cost for the
added bore ECI is estimated to be $40,800.
Regulatory Impact
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 removing Amendment 39-11124 (64 FR
17958, April 13, 1999), and by adding a new airworthiness directive, to
read as follows:
General Electric Company: Docket No. 98-ANE-41-AD. Supersedes AD 99-
08-18, Amendment 39-11124.
Applicability: General Electric Company (GE) CF6-6, CF6-45, and
CF6-50 series turbofan engines, installed on but not limited to
Airbus Industrie A300 series, Boeing 747 series, and McDonnell
Douglas DC-10 series airplanes.
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 critical life-limited rotating engine part failure,
which could result in an uncontained engine failure and damage to
the airplane, accomplish the following:
Inspections
(a) Within the next 30 days after the effective date of this AD,
revise the manufacturer's Time Limits Section of the Instructions
for Continued Airworthiness (ICA), and for air carrier operations
revise the approved continuous airworthiness maintenance program, by
adding the following:
``MANDATORY INSPECTIONS
(1) Perform inspections of the following parts at each piece-
part opportunity in accordance with the instructions provided in the
applicable manual provisions:
------------------------------------------------------------------------
Inspect per engine
Part nomenclature Part No. (P/N) shop manual chapter
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For CF6-6 Engines:
Disk, Fan Rotor Stage One.. All............ 72-21-03 Paragraph
2.F. or Paragraph
2.A.B. Fluorescent-
Penetrant Inspect,
and 72-21-03
Paragraph 3 or 3.A.
Eddy Current
Inspection
Disk, HPT Rotor Stage One.. All............ 72-53-03 Paragraph 1.
One Fluorescent-
Penetrant Inspect,
and 72-53-03
Paragraph 4. Eddy
Current Inspection of
the HPTR Disk Rim
Boltholes and 72-53-
03 Paragraph 5. Disk
Bore Area Eddy
Current Inspection
Disk, HPT Rotor Stage Two.. All............ 72-53-04 Paragraph 1.
Florescent-Penetrant
Inspect, and
Paragraph 4. Eddy
Current Inspection of
the Stage 2 HPTR Disk
Rim Boltholes and 72-
53-04 Paragraph 5.
Eddy Current
Inspection of the
Stage 2 Disk Inner
Boltholes and 72-53-
04 Paragraph 6. Disk
Bore Area Eddy
Current Inspection
For CF6-45, CF6-50 Engines:
[[Page 54589]]
Disk, Fan Rotor Stage One.. All............ Task 72-21-03-230-051
Fluorescent-Penetrant
Inspection, and Task
72-21-03-250-002-052
Manual Eddy Current
Inspection or 72-21-
03-250-003-053
Automated Eddy
Current Inspection
Disk, HPT Rotor Stage One.. All............ Task 72-53-03-230-001-
059 Fluorescent-
Penetrant Inspect
Disk, and Task 72-53-
03-250-052 Eddy
Current Inspection of
the HPTR Stage 1 Rim
Boltholes, and Task
72-53-03-250-054 Disk
Bore Area Eddy
Current Inspection
Disk, HPT Rotor Stage Two.. All............ Task 72-53-04-230-001-
057 Fluorescent-
Penetrant Inspect
Disk, and Task 72-53-
04-250-053 Eddy
Current Inspection of
the HPTR Stage 2 Rim
and/or Inner
Boltholes, and Task
72-53-04-250-056 Disk
Bore Area Eddy
Current Inspection
------------------------------------------------------------------------
(2) For the purposes of these mandatory inspections, piece-part
opportunity means:
(i) The part is considered completely disassembled when
accomplished in accordance with the disassembly instructions in the
manufacturer's engine manual; and
(ii) The part has accumulated more than 100 cycles in service
since the last piece-part opportunity inspection, provided that the
part was not damaged or related to the cause for its removal from
the engine.''
(b) Except as provided in paragraph (c) of this AD, and
notwithstanding contrary provisions in section 43.16 of the Federal
Aviation Regulations (14 CFR 43.16), these mandatory inspections
shall be performed only in accordance with the Time Limits Section
of the manufacturer's ICA.
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 Engine Certification Office (ECO). Operators
shall submit their requests through an appropriate FAA Principal
Maintenance Inspector (PMI), who may add comments and then send it
to the 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.
Ferry Flights
(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 airplane to a location where
the requirements of this AD can be accomplished.
Continuous Airworthiness Maintenance Program
(e) FAA-certificated air carriers that have an approved
continuous airworthiness maintenance program in accordance with the
record keeping requirement of Sec. 121.369(c) of the Federal
Aviation Regulations [14 CFR 121.369(c)] of this chapter must
maintain records of the mandatory inspections that result from
revising the Time Limits Section of the Instructions for Continuous
Airworthiness (ICA) and the air carrier's continuous airworthiness
program. Alternately, certificated air carriers may establish an
approved system of record retention that provides a method for
preservation and retrieval of the maintenance records that include
the inspections resulting from this AD, and include the policy and
procedures for implementing this alternate method in the air
carrier's maintenance manual required by Sec. 121.369(c) of the
Federal Aviation Regulations [14 CFR 121.369(c)]; however, the
alternate system must be accepted by the appropriate PMI and require
the maintenance records be maintained either indefinitely or until
the work is repeated. Records of the piece-part inspections are not
required under Sec. 121.380(a)(2)(vi) of the Federal Aviation
Regulations [14 CFR 121.380(a)(2) (vi)]. All other Operators must
maintain the records of mandatory inspections required by the
applicable regulations governing their operations.
Note 3: The requirements of this AD have been met when the
engine shop manual changes are made and air carriers have modified
their continuous airworthiness maintenance plans to reflect the
requirements in the engine shop manuals.
Issued in Burlington, Massachusetts, on September 30, 1999.
David A. Downey,
Assistant Manager, Engine and Propeller Directorate, Aircraft
Certification Service.
[FR Doc. 99-26209 Filed 10-6-99; 8:45 am]
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