AD 2000-03-03

[Federal Register Volume 65, Number 25 (Monday, February 7, 2000)]
[Rules and Regulations]
[Pages 5759-5760]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 00-2687]



[[Page 5759]]

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 99-NE-49-AD; Amendment 39-11560; AD 2000-03-03]
RIN 2120-AA64


Airworthiness Directives; General Electric Company CF34 Series 
Turbofan Engines

AGENCY:  Federal Aviation Administration, DOT.

ACTION:  Final rule.

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SUMMARY:  This amendment adopts a new airworthiness directive (AD), 
that 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 to include 
required enhanced inspection of selected critical life-limited parts at 
each piece-part exposure. This AD also requires that an air carrier's 
approved continuous airworthiness maintenance program incorporate these 
inspection procedures. This amendment is prompted by a Federal Aviation 
Administration (FAA) study of in-service events involving uncontained 
failures of critical rotating engine parts that indicated the need for 
improved inspections. The improved 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 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:  Effective March 13, 2000.

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 (238) 238-7199.

SUPPLEMENTARY INFORMATION:  A proposal to amend part 39 of the Federal 
Aviation Regulations (14 CFR part 39) to include an airworthiness 
directive (AD) that is applicable to General Electric Company CF34 
series turbofan engines was published in the Federal Register on 
October 7, 1999 (64 FR 54584). That action proposed to require, within 
the next 30 days after the effective date of this AD, revisions to the 
CF34 Engine Maintenance Program specified in the manufacturer's 
Instructions for Continued Airworthiness (ICA), and, for air carriers, 
their approved continuous airworthiness maintenance program. General 
Electric Company, the manufacturer of CF34-3A1 and -3B1 series turbofan 
engines, has provided the FAA with a detailed proposal that identifies 
and prioritizes the critical rotating engine parts with the highest 
potential to hazard the airplane in the event of failure, along with 
instructions for enhanced, focused inspection methods. These enhanced 
inspections will be conducted at piece-part opportunity, as defined in 
this AD, rather than at specific inspection intervals.

Comments Received

    Interested persons have been afforded an opportunity to participate 
in the making of this amendment. Due consideration has been given to 
the comments received.

Change Name of Manual Section

    One commenter (the manufacturer) states that the proposal should 
reference the Airworthiness Limitations Section instead of the Time 
Limits Section. The FAA concurs in part. The reference to the Time 
Limits Section will be removed and changed to the CF34 Engine 
Maintenance Program in this final rule.

Part Numbers (P/Ns)

    One commenter notes that in Table 804 of the proposal, the Stage 2 
High Pressure Turbine (HPT) Rotor Disk, P/N 5079T53 is incorrect. The 
correct P/N is 5079T73. The FAA concurs. To make this AD consistent 
with other enhanced inspection ADs, and in response to comments 
received on the other ADs, the P/Ns have been removed from Table 804 
and the word ``all'' has been substituted for P/Ns.

Concurs With Proposal

    One commenter concurs with the rule as proposed.

Conclusion

    After careful review of the available data, including the comments 
noted above, the FAA has determined that air safety and the public 
interest require the adoption of the rule with the changes described 
previously. The FAA has determined that these changes will neither 
increase the economic burden on any operator nor increase the scope of 
the AD.

Economic Analysis

    The FAA estimates that 352 engines installed on aircraft of US 
registry will be affected by this AD, that it will take approximately 2 
work hours per engine to accomplish the required actions, and that the 
average labor rate is $60 per work hour. The total cost of the new 
inspections per engine will be approximately $120 per year. Using 
average shop visit rates, 275 engines are expected to be affected per 
year. The annual cost impact of the AD on US operators is therefore 
estimated to be $33,000.

Regulatory Impact

    The regulations adopted herein will 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. Therefore, it 
is determined that this final rule does not have federalism 
implications under Executive Order (EO) 13132.
    For the reasons discussed above, I certify that this action (1) is 
not a ``significant regulatory action'' under EO 12866; (2) is not a 
``significant rule'' under DOT Regulatory Policies and Procedures (44 
FR 11034, February 26, 1979); and (3) 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 final 
evaluation has been prepared for this action and it is contained in the 
Rules Docket. A copy of it may be obtained from 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.

Adoption of the Amendment

    Accordingly, pursuant to the authority delegated to me by the 
Administrator, the Federal Aviation Administration amends 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 adding the following new 
airworthiness directive:

2000-03-03  General Electric Company: Amendment 39-11560. Docket 99-
NE-49-AD.

    Applicability: General Electric Company (GE) CF34-3A1 and -3B1 
series turbofan

[[Page 5760]]

engines, installed on but not limited to Bombardier Canadair CL601R 
(RJ) aircraft.

    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 CF34 Engine Maintenance Program, Chapter 5-21-00, of the 
GE CF34 Series Turbofan Engine Manual, SEI-756, and for air carrier 
operations revise the approved continuous airworthiness maintenance 
program, by adding the following:
    ``9. CF34-3A1 and CF34-3B1 Engine Maintenance Program--Shop 
Level 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.
    B. Piece-part exposure is defined as follows:
    (1) For engines that utilize the ``On Condition'' maintenance 
requirements:
    The part is considered completely disassembled when done in 
accordance with the disassembly instructions in the GEAE engine 
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
----------------------------------------------------------------------------------------------------------------
            Part nomenclature              Manual chapter/section/subject           Mandatory inspection
----------------------------------------------------------------------------------------------------------------
Fan Disk (all)..........................  72-21-00, Inspection............  All areas (FPI) \1\
                                                                            Bores (ECI) \2\
Stage 1 high pressure turbine (HPT)       72-46-00, Inspection............  All areas (FPI) \1\
 Rotor Disk (all).                                                          Bores (ECI) \2\
                                                                            Boltholes (ECI) \2\
                                                                            Air Holes (ECI) \2\
Stage 2 HPT Rotor Disk (all)............  72-46-00, Inspection............  All areas (FPI) \1\
                                                                            Bores (ECI) \2\
                                                                            Boltholes (ECI) \2\
                                                                            Air Holes (ECI) \2\
HPT Rotor Outer Torque Coupling (all)...  72-46-00, Inspection............  All areas (FPI)\1\
                                                                            Bore (ECI) \1\
----------------------------------------------------------------------------------------------------------------
\1\ FPI = Fluorescent Penetrant Inspection Method.
\2\ ECI = Eddy Current Inspection.

    (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 CF34 Engine 
Maintenance Program, Chapter 5-21-00, of the General Electric 
Company, CF34 Series Turbofan Engine Manual, SEI-756.
    (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. Operators shall 
submit their requests through an appropriate FAA Principal 
Maintenance Inspector (PMI), who may add comments and then send it 
to the Engine Certification Office.

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

    (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.
    (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.

    (f) This amendment becomes effective on March 13, 2000.

    Issued in Burlington, Massachusetts, on February 1, 2000.
David A. Downey,
Assistant Manager, Engine and Propeller Directorate, Aircraft 
Certification Service.
[FR Doc. 00-2687 Filed 2-4-00; 8:45 am]
BILLING CODE 4910-13-P