[Federal Register Volume 66, Number 196 (Wednesday, October 10, 2001)]
[Proposed Rules]
[Pages 51607-51609]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 01-25400]


 ========================================================================
 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. 66, No. 196 / Wednesday, October 10, 2001 / 
Proposed Rules  

[[Page 51607]]



DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 98-ANE-39-AD]
RIN 2120-AA64


Airworthiness Directives; General Electric Company GE90 Series 
Turbofan Engines

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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

SUMMARY: The FAA proposes to supersede an existing airworthiness 
directive (AD), which is applicable to General Electric Company (GE) 
GE90 series turbofan engines. That AD currently requires revisions to 
the Life 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 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. 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 10, 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-39-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: Ian Dargin, Aerospace Engineer, Engine 
Certification Office, FAA, Engine and Propeller Directorate, 12 New 
England Executive Park, Burlington, MA 01803-5299; telephone (781) 238-
7178, 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 action 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 action must submit a self-addressed, 
stamped postcard on which the following statement is made: ``Comments 
to Docket Number 98-ANE-39-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. 98-ANE-39-AD, 12 New England Executive 
Park, Burlington, MA 01803-5299.

Discussion

    On April 14, 2000, the FAA issued AD 2000-08-10, Amendment 39'11696 
(65 FR 21642, April 24, 2000), to require revisions to the Life Limits 
Section of the manufacturer's Instructions for Continued Airworthiness 
(ICA) for GE GE90 series turbofan engines to include required 
inspection of selected critical life-limited parts at each piece-part 
exposure.

Additional Inspection Procedures

    Since that AD was issued, an 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 develop on other products of this same type design, the 
proposed AD would supersede AD 2000-08-10 to add additional critical 
life-limited parts for enhanced inspection at each piece-part 
opportunity.
    This proposed AD would also delete the GE90-92B model from the 
applicability and add recently certified engine model, the GE 90-94B. 
Reference to the GE90-92B model is removed from the AD applicability 
because the manufacturer has informed the FAA that no engines of that 
model were produced and has requested that the FAA remove this model 
designation.

[[Page 51608]]

Economic Analysis

    The FAA estimates that 31 engines installed on airplanes of US 
registry would be affected by this proposed AD, that it would take 
approximately 172 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 $10320 per engine. It is further estimated 
that there will be about 34 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 that will 
be mandated by this proposed AD on U.S. operators is estimated to be 
$350880.

Regulatory Impact

    This proposed rule does not have federalism implications, as 
defined in Executive Order 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 
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 39-11696 (65 FR 
21642, April 24, 2000), and by adding a new airworthiness directive, to 
read as follows:

General Electric Company: Docket No. 98-ANE-39-AD. Supersedes AD 
2000-08-10, Amendment 39-11696.

Applicability

    This airworthiness directive (AD) is applicable to General 
Electric Company (GE) GE90-76B/ -77B/ -85B/ -90B/ -94B series 
turbofan engines. These engines are installed on but not limited to 
Boeing 777 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

    Compliance with this AD is 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, accomplish the following:

Inspections

    (a) Within the next 30 days after the effective date of this AD, 
revise the manufacturer's Life 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)       manual chapter
------------------------------------------------------------------------
For GE90 Engines:
    HPCR Disk, Stage 1........  All..............  72-31-05-200-001-001
                                                    Fluorescent
                                                    Penetrant Inspection
                                                    (subtask 72-31-05-
                                                    230-051), and 72-31-
                                                    05-200-001-001 Eddy
                                                    Current Inspection
                                                    of the Bore, and 72-
                                                    31-05-200-001-001
                                                    Eddy Current
                                                    Inspection of the
                                                    Dovetail Slots.
    HPCR Spool, Stage 2-6.....  All..............  72-31-06-200-001-001
                                                    Fluorescent
                                                    Penetrant Inspection
                                                    (subtask 72-31-06-
                                                    230-051), and 72-31-
                                                    06-200-001-001 Eddy
                                                    Current Inspection
                                                    of the S2 Dovetail
                                                    Slots.
    HPCR, Disk, Stage 7.......  All..............  72-31-07-200-001-001
                                                    Fluorescent
                                                    Penetrant Inspection
                                                    (subtask 72-31-07-
                                                    230-051), and 72-31-
                                                    07-200-001-001 Eddy
                                                    Current Inspection
                                                    (subtask 72-31-07-
                                                    250-051 or 72-31-07-
                                                    230-052 or 72-31-07-
                                                    230-053.
    HPCR Spool, Stage 8-10....  All..............  72-31-08-200-001-001
                                                    Fluorescent
                                                    Penetrant Inspection
                                                    and 72-31-08-800-001
                                                    Eddy Current
                                                    Inspection of the
                                                    stage 8-9 inertia
                                                    weld.
    HPCR Seal, Compressor       All..............  72-31-09-200-001-001
     Discharge Pressure.                            Fluorescent
                                                    Penetrant Inspection
                                                    (subtask 72-31-09-
                                                    230-051), and 72-31-
                                                    09-200-001-001 Eddy
                                                    Current Inspection
                                                    of the Boltholes.
    HPCR Ring, Tube Supporter.  All..............  72-31-10-200-001-001
                                                    Fluorescent
                                                    Penetrant
                                                    Inspection.
    HPTR, Interstage Seal.....  All..............  72-53-03-200-001-001
                                                    Fluorescent
                                                    Penetrant Inspection
                                                    (subtask 72-53-03-
                                                    230-053), and 72-53-
                                                    03-200-001-001 Eddy
                                                    Current Inspection
                                                    of the Bore.
    Fan Disk, Stage 1.........  All..............  72-21-03-200-001-001
                                                    Fluorescent
                                                    Penetrant Inspection
                                                    (subtask 72-21-03-
                                                    230-051), and 72-21-
                                                    03-200-001-001 Eddy
                                                    Current, and 72-21-
                                                    03-200-001-001
                                                    Ultrasonic
                                                    Inspection of
                                                    Dovetail Slots.

[[Page 51609]]

 
    HPTR Disk, Stage 1........  All..............  72-53-02-200-001-002
                                                    Fluorescent
                                                    Penetrant Inspection
                                                    (subtask 72-53-02-
                                                    160-051), and 72-53-
                                                    02-200-001-002 Eddy
                                                    Current Inspection
                                                    of the Bore.
    HPTR Disk, Stage 2........  All..............  72-53-04-200-001-004
                                                    Fluorescent
                                                    Penetrant Inspection
                                                    (subtask 72-53-04-
                                                    230-052), and 72-53-
                                                    04-200-001-004 Eddy
                                                    Current Inspection
                                                    of the Bore.
    LPTR Cone Shaft...........  All..............  72-56-07-200-001-001
                                                    Fluorescent
                                                    Penetrant
                                                    Inspection.
    LPTR Fan Mid Shaft........  All..............  72-58-01-200-001-001
                                                    Magnetic Particle
                                                    Inspection.
    LPTR Disk, Stage 1........  All..............   72-56-02-200-001-001
                                                    Fluorescent
                                                    Penetrant
                                                    Inspection.
    LPTR Disk, Stage 2........  All..............  72-56-02-200-001-001
                                                    Fluorescent
                                                    Penetrant
                                                    Inspection.
    LPTR Disk, Stage 3........  All..............  72-56-02-200-001-001
                                                    Fluorescent
                                                    Penetrant
                                                    Inspection.
    LPTR Disk, Stage 4........  All..............  72-56-02-200-001-001
                                                    Fluorescent
                                                    Penetrant
                                                    Inspection.
    LPTR Disk, Stage 5........  All..............  72-56-02-200-001-001
                                                    Fluorescent
                                                    Penetrant
                                                    Inspection.
    LPTR Disk, Stage 6........  All..............  72-56-02-200-001-001
                                                    Fluorescent
                                                    Penetrant
                                                    Inspection.
    Fan Shaft, Forward........  All..............  72-22-01-200-001-001
                                                    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.''
    (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 
must be performed only in accordance with the Life 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 
must 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.

Special Flight Permits

    (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 
recordkeeping 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 
Life Limits Section of the ICA and the air carrier's continuous 
airworthiness program. Alternatively, 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 manual changes are made and air carriers have modified their 
continuous airworthiness maintenance plans to reflect the 
requirements in the engine manuals.


    Issued in Burlington, Massachusetts, on September 26, 2001.
Jay J. Pardee,
Manager, Engine and Propeller Directorate, Aircraft Certification 
Service.
[FR Doc. 01-25400 Filed 10-9-01; 8:45 am]
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