[Federal Register Volume 66, Number 194 (Friday, October 5, 2001)]
[Proposed Rules]
[Pages 50891-50894]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 01-25054]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 99-NE-49-AD]
RIN 2120-AA64


Airworthiness Directives; General Electric Company CF34 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), that is applicable 
to General Electric Company CF34 series turbofan engines. That AD 
currently requires revisions to the Engine Maintenance Program 
specified in the manufacturer's Instructions for Continued 
Airworthiness (ICA) for General Electric Company (GE) CF34 series 
turbofan engines. This proposal would modify the airworthiness 
limitations section of the manufacturer's

[[Page 50892]]

manual and an air carrier's approved continuous airworthiness 
maintenance program to incorporate additional inspection requirements. 
An 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. 99-NE-49-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 by appointment 
between 8 a.m. and 4:30 p.m., Monday through Friday, except Federal 
holidays.

FOR FURTHER INFORMATION CONTACT: Barbara Caufield, Aerospace Engineer, 
Engine Certification Office, FAA, Engine and Propeller Directorate, 12 
New England Executive Park, Burlington, MA 01803-5299; telephone (781) 
238-7146, 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 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 99-NE-49-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-49-AD, 12 New England Executive Park, 
Burlington, MA 01803-5299.

Discussion

    On May 7, 2001, the Federal Aviation Administration (FAA) issued 
airworthiness directive (AD) 2000-03-03 R1, Amendment 39-12228 (66 FR 
26787, May 15, 2001), to require revisions to the Engine Maintenance 
Program specified in the manufacturer's Instructions for Continued 
Airworthiness (ICA) for General Electric Company (GE) CF34 series 
turbofan engines at each piece part exposure exposure.

Additional Inspection Procedures

    Since the issuance of that AD, 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 2000-03-03 R1 to add additional 
inspections for certain critical rotating engine parts at each piece-
part opportunity.

Economic Analysis

    The FAA estimates that 1022 engines installed on aircraft of U.S. 
registry would be affected by this proposed AD. The FAA also estimates 
that it would take approximately 32 work hours per engine to accomplish 
the proposed inspections, and that the average labor rate is $60 per 
work hour. Using average shop visit rates, 200 engines are expected to 
be affected per year. Based on these figures, the total annual cost 
impact of the proposed AD on U.S. operators is estimated to be 
$384,000.

Regulatory Analysis

    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 39-12228 (66 FR 
26787, May 15, 2001), and by adding a new airworthiness directive:


[[Page 50893]]


General Electric Company: Docket No. 99-NE-49-AD. Supersedes AD 
2000-03-03 R1, Amendment 39-12228.

Applicability

    This airworthiness directive (AD) is applicable to General 
Electric Company (GE) CF34-3A1 and -3B1 series turbofan engines, 
installed on but not limited to Bombardier Canadair CL 600-2B19(RJ) 
aircraft.

    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 CF34 Engine Maintenance Program, Chapter 5-21-00, of the 
GE CF34 Series Turbofan Engine Manual, SEI-756. For air carrier 
operations, revise the approved continuous airworthiness maintenance 
program, by adding the following:
    9. CF34-3A1 and CF34-3B1 Engine Maintenance Program--Mandatory 
Inspection Requirements.
    (A) This procedure is used to identify specific piece-parts that 
require mandatory inspections that must be accomplished at each 
piece-part exposure using the applicable Chapters referenced in 
Table 804 for the inspection requirements. The inspection 
requirements listed in Table 804 are not required for any piece-part 
exposure resulting when the engine remains on-wing while performing 
maintenance practice, special procedure Number 41 listed in SEI-756, 
chapter 72-00-00.
    (B) Piece-part exposure is defined as follows: Note: Fan disk 
piece-part includes the fan disk with the 56 fan pin bushings 
installed.
    (1) For engines that utilize the ``On Condition'' maintenance 
requirements: The part is considered completely disassembled to the 
piece-part level when done in accordance with the disassembly 
instructions in the GEAE authorized overhaul Engine Manual, and 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.
    (2) For engines that utilize the ``Hard Time'' maintenance 
requirements: The part is considered completely disassembled when 
done in accordance with the disassembly instructions used in the 
``Minor Maintenance'' or ``Overhaul'' instructions in the GEAE 
engine authorized Engine Manual, and 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.
    C. Refer to Table 804 below for the mandatory inspection 
requirements.

              Table 804.--Mandatory Inspection Requirements
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                                 Manual/chapter
      Part nomenclature          section/subject    Mandatory inspection
------------------------------------------------------------------------
Fan Disk (all)..............  72-21-00, INSPECTION  All areas (FPI).
                                                    Bores (ECI).
Stage 1 high pressure         72-46-00, INSPECTION  All areas (FPI).
 turbine (HPT) Rotor Disk                           Bores (ECI).
 (all).                                             Boltholes (ECI).
                                                    Air Holes (ECI).
Stage 2 HPT Rotor Disk (all)  72-46-00, INSPECTION  All Areas (FPI).
                                                    Bores (ECI).
(a) Boltless Rim                                    Boltholes (FPI).
 Configuration.                                     Air Holes (FPI).
(b) Bolted Rim Configuration                        Boltholes (ECI).
                                                    Air Holes (ECI).
HPT Rotor Outer Torque        72-46-00, INSPECTION  All areas (FPI).
 Coupling (all).                                    Bore (ECI).
Forward Fan Shaft (all).....  72-21-00, INSPECTION  All Areas (FPI).
Fan Drive Shaft (all).......  72-22-00, INSPECTION  All Areas (FPI).
Stage 1 Compressor Rotor      72-33-00, INSPECTION  All Areas (FPI).
 Disk (CF34-3A1) or.
Stage 1 Compressor Rotor
 Blisk (CF34-3B1) (all).
Compressor Forward Shaft      72-33-00, INSPECTION  All Areas (FPI).
 (all).
Stage 2 Compressor Rotor      72-33-00, INSPECTION  All Areas (FPI).
 Disk (all).
Stage 3-8 Compressor Rotor    72-33-00, INSPECTION  All Areas (FPI).
 Spool (all).
Stage 9 Compressor Rotor      72-33-00, INSPECTION  All Areas (FPI).
 Disk (all).
Compressor Rotor Rear Shaft   72-33-00, INSPECTION  All Areas (FPI).
 (all).
Compressor Discharge          72-33-00, INSPECTION  All non-coated Areas
 Rotating Seal (all).                                (FPI).
Stage 10-14 Compressor Rotor  72-33-00, INSPECTION  All non-coated Areas
 Spool (all).                                        (FPI).
Turbine Rear Shaft (LPT       72-53-00, INSPECTION  All Areas (FPI).
 Rotor) (all).
Stage 3 Turbine Disk (all)..  72-53-00, INSPECTION  All Areas (FPI).
Stage 4 Turbine Disk (all)..  72-53-00, INSPECTION  All Areas (FPI).
Stage 5 Turbine Disk (all)..  72-53-00, INSPECTION  All Areas (FPI).
Stage 6 Turbine Disk (all)..  72-53-00, INSPECTION  All Areas (FPI).
Turbine Driver Cone (all)...  72-53-00, INSPECTION  All Areas (FPI).
------------------------------------------------------------------------
FPI = Fluorescent Penetrant Inspection Method
ECI = Eddy Current Inspection''

    (b) Except as provided in paragraph (c) of this AD, and 
notwithstanding the provisions of section 43.16 of the Federal 
Aviation Regulations (14 CFR 43.16), these mandatory inspections 
shall be performed only in accordance with the CF34 Engine 
Maintenance Program, Chapter 5-21-00, of the General Electric 
Company, CF34 Series Turbofan Engine Manual, SEI-756.

[[Page 50894]]

Alternative Method 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 (PMI), 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 AD, 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 
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 CF34 Engine 
Maintenance Program 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 manual changes are made and air carriers have modified their 
continuous airworthiness maintenance plans to reflect the Engine 
Maintenance Program requirements specified in the GE CF34 Series 
Turbofan Engine Manual.


    Issued in Burlington, Massachusetts, on October 1, 2001.
Jay J. Pardee,
Manager, Engine and Propeller Directorate, Aircraft Certification 
Service.
[FR Doc. 01-25054 Filed 10-4-01; 8:45 am]
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