[Federal Register Volume 66, Number 194 (Friday, October 5, 2001)]
[Proposed Rules]
[Pages 50912-50915]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 01-25077]


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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: The Federal Aviation Administration (FAA) proposes to 
supersede 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 inspection of selected critical life-limited parts at 
each piece-part exposure. This proposal would modify the airworthiness 
limitations section of the manufacturer's manual and an air carrier's 
approved continuous airworthiness maintenance program to incorporate 
additional inspection requirements. A Federal Aviation Administration 
(FAA) study of in-service events involving uncontained failures of 
critical rotating engine parts has indicated the need for mandatory 
inspections. The mandatory inspections are needed to identify those 
critical rotating parts with conditions, which if allowed to continue 
in service, could result in uncontained failures. 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 4, 2001.

ADDRESSES: Submit comments in triplicate 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 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 14, 2000, the FAA issued AD 2000-08-11, Amendment 39-11697 
(65 FR 21636, April 24, 2000), 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 inspection of selected 
critical life-limited parts at each piece-part exposure.

Additional Inspection Procedures

    Since the issuance of that AD, a Federal Aviation Administration 
(FAA) study of in-service events involving uncontained failures of 
critical rotating engine parts has indicated the need for additional 
mandatory inspections. The mandatory inspections are needed to identify 
those critical rotating parts with conditions, which if allowed to 
continue in service, could result in uncontained failures. This 
proposal would modify the airworthiness limitations section of the 
manufacturer's manual and an air carrier's approved continuous 
airworthiness maintenance program to incorporate additional inspection 
requirements.

Proposed Actions

    Since an unsafe condition has been identified that is likely to 
exist or

[[Page 50913]]

develop on other products of this same type design, the proposed AD 
would supersede AD 2000-08-11 to add additional inspections for certain 
HPC and LPT components at each piece-part opportunity.

Economic Impact

    The FAA estimates that 730 engines installed on airplanes of US 
registry would be affected by this proposed AD, that it would take 
approximately 10 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 $600 per engine. It is further estimated that 
there will be about 299 shop visits per year that result in piece-part 
exposure of the additional affected components. Based on these figures, 
the total cost impact of the additional inspections on U.S. operators 
is estimated to be $179,400.

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 FR11034, 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 39-11697 (65 FR 
21636, April 24, 2000), and by adding a new airworthiness directive, to 
read as follows:

General Electric Company: Docket No. 98-ANE-41-AD. Supersedes AD 
2000-08-11, Amendment 39-11697.

    Applicability: This airworthiness directive (AD) is applicable 
to 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 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 already done.
    To prevent critical life-limited rotating engine part failure, 
which could result in an uncontained engine failure and damage to 
the airplane, do 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
------------------------------------------------------------------------
For CF6-6 Engines:
    Disk, Fan Rotor Stage One.  All..............  72-21-03  Paragraph
                                                    2.F. or Paragraph
                                                    2.A.B. Flourescent-
                                                    Penetrant Inspect,
                                                    and
                                                   72-21-03  Paragraph 3
                                                    or 3.A. Eddy Current
                                                    Inspection.
    Fan Forward Shaft.........  All..............  72-21-05  Paragraph
                                                    1. Magnetic Particle
                                                    Inspection.
    Fan Mid Shaft.............  All..............  72-24-01  Paragraph
                                                    1. and Paragraph 2.
                                                    Magnetic Particle
                                                    Inspection.
    Disk, HPC Rotor, Stage 1..  All..............  72-31-04  Paragraph
                                                    1. Fluorescent
                                                    Penetrant
                                                    Inspection.
    Disk, HPC Rotor, Stage 2..  All..............  72-31-05  Paragraph
                                                    1. Fluorescent
                                                    Penetrant
                                                    Inspection.
    Spool, HPC Rotor, Stages    All..............  72-31-06  Paragraph
     Three thru Nine.                               1. Fluorescent
                                                    Penetrant
                                                    Inspection.
    Disk, HPC Rotor, Stage 10.  All..............  72-31-07  Paragraph
                                                    1. Fluorescent
                                                    Penetrant
                                                    Inspection.
    Spool, HPC Rotor, Stages    All..............  72-31-08  Paragraph
     11-13.                                         1. Fluorescent
                                                    Penetrant
                                                    Inspection.
    Spool, HPC Rotor, Stages    All..............  72-31-08  Paragraph
     14-16.                                         1. Fluorescent
                                                    Penetrant
                                                    Inspection.
    HPC Rear Shaft............  All..............  72-31-09  Paragraph
                                                    1. and Paragraph
                                                    1.E. Fluorescent
                                                    Penetrant
                                                    Inspection.
    No. 4R Bearing Rotating     All..............  72-31-10 Fluorescent
     (CDP) Air Seal.                                Penetrant
                                                    Inspection.
    No. 4R Bearing Rotating     All..............  72-31-10
     (CDP) Air Seal Support.                        FluorescentPenetrant
                                                    Inspection.

[[Page 50914]]

 
    Disk, HPT Rotor Stage One.  All..............  72-53-03  Paragraph 1
                                                    . Flourescent-
                                                    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
                                                    . Flourescent-
                                                    Penetrant Inspect,
                                                    and
                                                   72-53-04  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.
    Disk, LPT Rotor, Stages     All..............  72-57-02  Paragraph
     One thru Five.                                 1. Fluorescent
                                                    Penetrant
                                                    Inspection.
    LPT Forward Shaft.........  All..............  72-57-03  Paragraph
                                                    1. Fluorescent
                                                    Penetrant
                                                    Inspection.
    LPT Rear Shaft............  All..............  72-57-04  Paragraph
                                                    1. Fluorescent
                                                    Penetrant
                                                    Inspection.
For CF6-45, CF6-50 Engines:
    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.
    Forward Shaft, Fan........  All..............  Task 72-21-05-240-056
                                                    Magnetic Particle
                                                    Inspection.
    Mid Shaft, Fan............  All..............  Task 72-24-01-240-001-
                                                    051 Magnetic
                                                    Particle Inspection.
    Disk, HPC Rotor Stage 1...  All..............  Task 72-31-04-230-001-
                                                    051 Fluorescent
                                                    Penetrant
                                                    Inspection.
    Disk, HPC Rotor Stage 2...  All..............  Task 72-31-05-230-001-
                                                    051 Fluorescent
                                                    Penetrant
                                                    Inspection.
    Spool, HPC Rotor Stages 3-  All..............  Task 72-31-06-230-001-
     9.                                             063 Fluorescent
                                                    Penetrant
                                                    Inspection.
    Disk, HPC Rotor Stage 10..  All..............  Task 72-31-07-230-001-
                                                    051 Fluorescent
                                                    Penetrant
                                                    Inspection.
    Spool, HPC Rotor Stages 11- All..............  Task 72-31-08-230-001-
     13.                                            051 Fluorescent
                                                    Penetrant
                                                    Inspection.
    Disk, HPC Rotor Stage 14..  All..............  Task 72-31-07-230-001-
                                                    055 Fluorescent
                                                    Penetrant
                                                    Inspection.
    Rear Shaft, HPC Rotor.....  All..............  Task 72-31-09-230-001-
                                                    051 Fluorescent
                                                    Penetrant
                                                    Inspection.
    Spool/Shaft, HPC Rotor      All..............  Task 72-31-26-230-001-
     Stages 11-14.                                  052 Fluorescent
                                                    Penetrant
                                                    Inspection.
    Rotating (CDP) Air Seal,    All..............  Task 72-31-10-230-001-
     No. 4R Bearing.                                051 Fluorescent
                                                    Penetrant
                                                    Inspection.
    Rotating (CDP) Air Seal     All..............  Task 72-31-10-230-001-
     Support, No. 4R Bearing.                       051 Fluorescent
                                                    Penetrant
                                                    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 72-53-03-250-060
                                                    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 72-53-04-250-060
                                                    Disk Bore Area Eddy
                                                    Current Inspection.
    Disks, LPT Rotor Stages 1-  All..............  Task 72-57-02-230-001-
     4.                                             051 Fluorescent
                                                    Penetrant
                                                    Inspection.
    Forward Shaft, LPTR.......  All..............  Task 72-57-03-230-001-
                                                    057 Fluorescent
                                                    Penetrant
                                                    Inspection.
    Rear Shaft, LPTR..........  All..............  Task 72-57-04-230-001-
                                                    051 Fluorescent
                                                    Penetrant
                                                    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.''

[[Page 50915]]

    (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.

Continuous Airworthiness Maintenance Program

    (d) 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)] 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 25, 2001.
Jay J. Pardee,
Manager, Engine and Propeller Directorate, Aircraft Certification 
Service.
[FR Doc. 01-25077 Filed 10-4-01; 8:45 am]
BILLING CODE 4910-13-P