Airworthiness Directives; General Electric Company CF34-3A1 and -3B1 Series Turbofan Engines

[Federal Register Volume 69, Number 146 (Friday, July 30, 2004)]
[Rules and Regulations]
[Pages 45562-45564]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 04-17040]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2004-18648; Directorate Identifier 2004-NE-26-AD; 
Amendment 39-13737; AD 2004-15-03]
RIN 2120-AA64


Airworthiness Directives; General Electric Company CF34-3A1 and -
3B1 Series Turbofan Engines

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule; request for comments.

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SUMMARY: The FAA is adopting a new airworthiness directive (AD) for 
General Electric Company (GE) CF34-3A1 and -3B1 series turbofan engines 
with certain serial numbers (SNs) of stage 5 low pressure turbine (LPT) 
disks, part number (P/N) 6078T92P01, and or certain SNs of stage 6 LPT 
disks, P/N 6089T89P01. This AD requires initial and repetitive visual 
and eddy current inspections of those disks. This AD also allows as 
optional terminating action to the repetitive inspections, replacement 
of those SN disks. This AD also requires replacement of certain stage 5 
and stage 6 LPT disks. This AD results from a report of a stage 5 LPT 
disk that failed due to cracking from low-cycle-fatigue (LCF) during 
factory testing. We are issuing this AD to prevent LCF failure of stage 
5 LPT disks and stage 6 LPT disks, which could lead to uncontained 
engine failure.

DATES: This AD becomes effective August 16, 2004. The Director of the 
Federal Register approved the incorporation by reference of certain 
publications listed in the regulations as of August 16, 2004.
    We must receive any comments on this AD by September 28, 2004.

ADDRESSES: Use one of the following addresses to submit comments on 
this AD.
    <bullet> DOT Docket Web site: Go to http://dms.dot.gov and follow 
the instructions for sending your comments electronically.
    <bullet> Government-wide rulemaking Web site: Go to http://www.regulations.gov and follow the instructions for sending your 
comments electronically.
    <bullet> Mail: Docket Management Facility; U.S. Department of 
Transportation, 400 Seventh Street, SW., Nassif Building, Room PL-401, 
Washington, DC 20590-001.
    <bullet> Fax: (202) 493-2251.
    <bullet> Hand Delivery: Room PL-401 on the plaza level of the 
Nassif Building,

[[Page 45563]]

400 Seventh Street, SW., Washington, DC, between 9 a.m. and 5 p.m., 
Monday through Friday, except Federal holidays.
    You can get the service information identified in this AD from GE 
Aircraft Engines, 1000 Western Avenue, Lynn, MA 01910; Attention: CF34 
Product Support Engineering, Mail Zone: 34017; telephone (781) 594-
6323; fax (781) 594-0600.
    You may examine the comments on this AD in the AD docket on the 
Internet at http://dms.dot.gov.

FOR FURTHER INFORMATION CONTACT: Robert Grant, Aerospace Engineer, 
Engine Certification Office, FAA, Engine and Propeller Directorate, 12 
New England Executive Park, Burlington, MA 01803-5299; telephone (781) 
238-7757; fax (781) 238-7199.

SUPPLEMENTARY INFORMATION: In February of 2004, we became aware of an 
LCF failure of a stage 5 LPT disk that occurred during factory testing. 
GE performed a metallurgical evaluation of the disk. The evaluation 
showed that the origin of the LCF failure was at a disk location 
contacted inadvertently by electrochemical etch probes. These probes 
were used to match-mark components during engine assembly. The 
evaluation concluded that the probe contact caused damage known as 
electrical arc-out. Electrical arc-out damage can lead to LCF failure 
of the disk. This condition, if not corrected, could result in 
uncontained engine failure.

Relevant Service Information

    We have reviewed and approved the technical contents of GE Alert 
Service Bulletin No. CF34-AL S/B 72-A0173, Revision 3, dated July 20, 
2004, that lists applicable disks by SN, and describes the procedures 
for performing visual and eddy current inspections on the applicable 
stage 5 LPT disks and stage 6 LPT disks.

FAA's Determination and Requirements of This AD

    The unsafe condition described previously is likely to exist or 
develop on other GE CF34-3A1 and -3B1 series turbofan engines of the 
same type design. We are issuing this AD to prevent LCF failure of 
stage 5 LPT disks and stage 6 LPT disks, which could lead to 
uncontained engine failure. This AD requires:
    <bullet> Initial and repetitive visual and eddy current inspections 
of certain SN stage 5 LPT disks and stage 6 LPT disks.
    <bullet> Replacement of the suspect disks as optional terminating 
action to the repetitive inspections.
    <bullet> Replacement of certain stage 5 LPT disks and stage 6 LPT 
disks.
    You must use the service information described previously to 
perform the actions required by this AD.

FAA's Determination of the Effective Date

    Since an unsafe condition exists that requires the immediate 
adoption of this AD, we have found that notice and opportunity for 
public comment before issuing this AD are impracticable, and that good 
cause exists for making this amendment effective in less than 30 days.

Docket Management System (DMS)

    We have implemented new procedures for maintaining AD dockets 
electronically. As of May 17, 2004, we posted new AD actions on the DMS 
and assigned a DMS docket number. We track each action and assign a 
corresponding Directorate identifier. The DMS docket number is in the 
form ``Docket No. FAA-200X-XXXXX.'' Each DMS docket also lists the 
Directorate identifier (``Old Docket Number'') as a cross-reference for 
searching purposes.

Comments Invited

    This AD is a final rule that involves requirements affecting flight 
safety and was not preceded by notice and an opportunity for public 
comment; however, we invite you to submit any written relevant data, 
views, or arguments regarding this AD. Send your comments to an address 
listed under ADDRESSES. Include ``AD Docket No. FAA-2004-18648; 
Directorate Identifier 2004-NE-26-AD'' in the subject line of your 
comments. We specifically invite comments on the overall regulatory, 
economic, environmental, and energy aspects of the rule that might 
suggest a need to modify it.
    We will post all comments we receive, without change, to http://dms.dot.gov, including any personal information you provide. We will 
also post a report summarizing each substantive verbal contact with FAA 
personnel concerning this AD. Using the search function of the DMS Web 
site, anyone can find and read the comments in any of our dockets, 
including the name of the individual who sent the comment (or signed 
the comment on behalf of an association, business, labor union, etc.). 
You may review the DOT's complete Privacy Act Statement in the Federal 
Register published on April 11, 2000 (65 FR 19477-78), or you may visit 
http://dms.dot.gov.
    We are reviewing the writing style we currently use in regulatory 
documents. We are interested in your comments on whether the style of 
this document is clear, and your suggestions to improve the clarity of 
our communications with you. You can get more information about plain 
language at http://www.faa.gov/language and http://www.plainlanguage.gov.

Examining the AD Docket

    You may examine the docket that contains the AD, any comments 
received, and any final disposition in person at the DMS Docket Offices 
between 9 a.m. and 5 p.m., Monday through Friday, except Federal 
holidays. The Docket Office (telephone (800) 647-5227) is located on 
the plaza level of the Department of Transportation Nassif Building at 
the street address stated in ADDRESSES. Comments will be available in 
the AD docket shortly after the DMS receives them.

Regulatory Findings

    We have determined that this AD will not have federalism 
implications under Executive Order 13132. This AD 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.
    For the reasons discussed above, I certify that the 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. 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.
    We prepared a summary of the costs to comply with this AD and 
placed it in the AD Docket. You may get a copy of this summary at the 
address listed under ADDRESSES.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Incorporation by 
reference, Safety.

Adoption of the Amendment

0
Under 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

0
1. The authority citation for part 39 continues to read as follows:

    Authority: 49 U.S.C. 106(g), 40113, 44701.

[[Page 45564]]

Sec.  39.13  [Amended]

0
2. The FAA amends Sec.  39.13 by adding the following new airworthiness 
directive:

2004-15-03 General Electric Company: Amendment 39-13737. Docket No. 
FAA-2004-18648; Directorate Identifier 2004-NE-26-AD.

Effective Date

    (a) This airworthiness directive (AD) becomes effective August 
16, 2004.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to General Electric Company (GE) CF34-3A1 
and -3B1 series turbofan engines with stage 5 low pressure turbine 
(LPT) disks, part number (P/N) 6078T92P01, and or stage 6 LPT disks, 
P/N 6089T89P01, with serial numbers (SNs) listed in Figure 3 of GE 
Alert Service Bulletin (ASB) No. CF34-AL S/B 72-A0173, Revision 3, 
dated July 20, 2004. These engines are installed on, but not limited 
to, Bombardier Canadair CL600-2B19 (RJ) airplanes.

Unsafe Condition

    (d) This AD results from a report of a stage 5 LPT disk that 
failed due to cracking from low-cycle-fatigue during factory 
testing. The crack started at the site of an electrical arc-out.

Compliance

    (e) You are responsible for having the actions required by this 
AD performed within the compliance times specified unless the 
actions have already been done.

Initial Inspection or Replacement

    (f) Using the compliance schedule in Table 1 of this AD:
    (1) Visually inspect and eddy current inspect (ECI) applicable 
stage 5 LPT disks and applicable stage 6 LPT disks using paragraphs 
3.C.(1) through 3.E.(6) of GE ASB No. CF34-AL S/B 72-A0173, Revision 
3, dated July 20, 2004, if the inspections can be completed within 9 
calendar months after the effective date of this AD; or
    (2) If the inspections specified in paragraph (f)(1) of this AD 
cannot be completed within 9 calendar months after the effective 
date of this AD, replace applicable stage 5 LPT disks and applicable 
stage 6 LPT disks with a serviceable disk using the compliance 
schedule in Table 1 of this AD.
    (3) The requirements of paragraphs (f)(1) and (f)(2) of this AD 
do not apply if the inspections were conducted using paragraph 
(g)(1) of this AD.

                      Table 1.--Compliance Schedule
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                                             Then perform the actions
                                           defined in paragraph (f) of
  On the effective date of this AD, if      this AD at next piece-part
             the disk has:                 exposure, not to exceed the
                                                 accumulation of:
------------------------------------------------------------------------
(i) 14,750 or more cycles-since-new      An additional 250 cycles-in-
 (CSN) and has not been fluorescent       service (CIS) after the
 penetrant inspected (FPI) at an          effective date of this AD.
 earlier piece-part exposure.
(ii) 14,750 or more CSN and has been     An additional 500 CIS after the
 FPI at an earlier piece-part exposure.   effective date of this AD.
(iii) 14,500 or more CSN but fewer than  An additional 500 CIS after the
 14,750 CSN.                              effective date of this AD.
(iv) 14,250 or more CSN but fewer than   An additional 750 CIS after the
 14,500 CSN.                              effective date of this AD.
(v) 13,000 or more CSN but fewer than    An additional 1,000 CIS after
 14,250 CSN.                              the effective date of this AD.
(vi) 2,500 or more CSN but fewer than    An additional 4,000 CIS after
 13,000 CSN.                              the effective date of this AD,
                                          or 14,000 CSN, whichever comes
                                          first.
(vii) Fewer than 2,500 cycles-since-new  6,500 CSN.
 (CSN).
------------------------------------------------------------------------

    (g) Before installation in an airplane:
    (1) Visually inspect and ECI applicable stage 5 LPT disks and 
applicable stage 6 LPT disks installed in replacement engines or 
replacement LPT modules using paragraphs 3.C.(1) through 3.E.(6) of 
GE ASB No. CF34-AL S/B 72-A0173, Revision 3, dated July 20, 2004, if 
the inspections can be completed within 9 calendar months after the 
effective date of this AD; or
    (2) If the inspections specified in paragraph (g)(1) of this AD 
cannot be completed within 9 calendar months after the effective 
date of this AD, replace applicable stage 5 LPT disks and applicable 
stage 6 LPT disks installed in replacement engines or replacement 
LPT modules with a serviceable disk.

Repetitive Inspections

    (h) For stage 5 LPT disks and stage 6 LPT disks initially 
inspected as specified in paragraph (f)(1) or (g)(1) of this AD, 
perform repetitive visual inspections and ECIs within every 3,100 
cycles-since-last-inspection, using paragraphs 3.C.(1) through 
3.E.(6) of GE ASB No. CF34-AL S/B 72-A0173, Revision 3, dated July 
20, 2004, until the life limit of the part is reached.

Disks That Pass Inspection

    (i) If a disk passes inspection, it must be reinstalled into the 
same LPT module it was removed from.

Optional Terminating Action

    (j) Replacement of an applicable stage 5 LPT disk or applicable 
stage 6 LPT disk with a disk not listed in Figure 3 of GE ASB No. 
CF34-AL S/B 72-A0173, Revision 3, dated July 20, 2004, is 
terminating action to the inspections required by this AD for that 
disk.

Definitions

    (k) For the purposes of this AD, a serviceable disk is defined 
as a disk that has a SN not listed in Figure 3 of GE ASB No. CF34-AL 
S/B 72-A0173, Revision 3, dated July 20, 2004.
    (l) For the purposes of this AD, the definition of piece-part 
exposure for the stage 5 LPT disk is when the disk is separated from 
the forward and aft bolted joints.
    (m) For the purpose of this AD, the definition of piece-part 
exposure for the stage 6 LPT disk is when the disk is separated from 
the forward bolted joint.
    (n) For the purposes of this AD, the definition of a replacement 
engine or replacement LPT module is an engine or LPT module that is 
not installed on an operational airplane on the effective date of 
this AD.

Alternative Methods of Compliance

    (o) The Manager, Engine Certification Office, has the authority 
to approve alternative methods of compliance for this AD if 
requested using the procedures found in 14 CFR 39.19.

Material Incorporated by Reference

    (p) You must use GE Aircraft Engines ASB No. CF34-AL S/B 72-
A0173, Revision 3, dated July 20, 2004, to perform the visual 
inspections, ECIs, and disk replacements required by this AD. The 
Director of the Federal Register approved the incorporation by 
reference of this service bulletin in accordance with 5 U.S.C. 
552(a) and 1 CFR part 51. You can get a copy from GE Aircraft 
Engines, 1000 Western Avenue, Lynn, MA 01910; Attention: CF34 
Product Support Engineering, Mail Zone: 34017; telephone (781) 594-
6323; fax (781) 594-0600, or at the National Archives and Records 
Administration (NARA). For information on the availability of this 
material at NARA, call 202-741-6030, or go to: http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html.

Related Information

    (q) GE Alert Service Bulletin No. CF34-AL S/B 72-A0178 pertains 
to the subject of this AD.

    Issued in Burlington, Massachusetts, on July 20, 2004.
Francis A. Favara,
Acting Manager, Engine and Propeller Directorate, Aircraft 
Certification Service.
[FR Doc. 04-17040 Filed 7-29-04; 8:45 am]
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