[Federal Register Volume 69, Number 157 (Monday, August 16, 2004)]
[Rules and Regulations]
[Pages 50299-50302]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 04-18635]


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DEPARTMENT OF TRANSPORTATION (DOT)

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2004-18648; Directorate Identifier 2004-NE-26-AD; 
Amendment 39-13773; AD 2004-15-03R1]
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 revising an existing 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 6078T89P01. That AD currently requires 
initial and repetitive visual and eddy current inspections of those 
disks. That AD also allows as optional terminating action to the 
repetitive inspections, replacement of those SN disks. Also, that AD 
requires replacement of certain stage 5 and stage 6 LPT disks. This ad 
requires the same actions. This AD results from the discovery that an

[[Page 50300]]

incorrect part number for stage 6 LPT disks was published in the 
existing AD and from the need to allow credit for actions completed per 
previous releases of Alert Service Bulletin CF34-AL S/B 72-A0173. 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: Effective August 31, 2004. The incorporation of certain 
publications, as listed in the regulations, was approved previously by 
the Director of the Federal Register as of August 16, 2004 (69 FR 
45562; July 30, 2004).
    We must receive any comments on this AD by October 15, 2004.

ADDRESSES: Use one of the following addresses to submit comments on 
this proposed AD.
     DOT Docket Web site: Go to http://dms.dot.gov and follow 
the instructions for sending your comments electronically.
     Government-wide rulemaking Web site: Go to http://www.regulations.gov and follow the instructions for sending your 
comments electronically.
     Mail: Docket Management Facility; U.S. Department of 
Transportation, 400 Seventh Street, SW., Nassif Building, Room PL-401, 
Washington, DC 20590-001.
     Fax: (202) 493-2251.
     Hand Delivery: Room PL-401 on the plaza level of the 
Nassif Building, 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: On July 20, 2004, the FAA issued AD 2004-15-
03, Amendment 39-13737 (69 FR 45562; July 30, 2004). That AD requires:
     Initial and repetitive visual and eddy current inspections 
of certain SN stage 5 LPT disks and stage 6 LPT disks.
     Replacement of the suspect disks as optional terminating 
action to the repetitive inspections.
     Replacement of certain stage 5 LPT disks and stage 6 LPT 
disks.
    That AD was the result of a report of a stage 5 LPT disk that 
failed due to cracking from low-cycle-fatigue (LCF) during factory 
testing. That condition, if not corrected, could result in uncontained 
engine failure.

Actions Since AD 2004-15-03 Was Issued

    Since that AD was issued, we discovered that we published an 
incorrect part number (P/N) of 6089T89P01 for stage 6 LPT disks. This 
AD revision corrects that P/N to 6078T89P01. Also, since that AD was 
issued, we determined that credit for actions completed per previous 
releases of Alert Service Bulletin CF34-AL S/B 72-A0173 need to be 
allowed. This AD revision adds a paragraph in the compliance section to 
allow that credit.

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:
     Initial and repetitive visual and eddy current inspections 
of certain SN stage 5 LPT disks and stage 6 LPT disks.
     Replacement of the suspect disks as optional terminating 
action to the repetitive inspections.
     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 No. 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-

[[Page 50301]]

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.

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.


Sec.  39.13  [Amended]

0
2. The FAA amends Sec.  39.13 by removing Amendment 39-13737 (69 FR 
45562; July 30, 2004), and by adding a new airworthiness directive, 
Amendment 39-13773, to read as follows:

2004-15-03R1 General Electric Company: Amendment 39-13773. Docket 
No. FAA-2004-18648; Directorate Identifier 2004-NE-26-AD.

Effective Date

    (a) This airworthiness directive (AD) becomes effective August 
31, 2004.

Affected ADs

    (b) This AD revises AD 2004-15-03, Amendment 39-13737.

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 6078T89P01, 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:
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(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.

[[Page 50302]]

Actions Completed per Previous Releases of Alert Service Bulletin CF34-
AL S/B 72-A0173

    (k) Actions completed before the effective date of this AD using 
GE ASB No. CF34-AL S/B 72-A0173, dated April 2, 2004; or Revision 1, 
dated May 20, 2004; or Revision 2, dated June 22, 2004; or Revision 
3, dated July 20, 2004; are considered acceptable for compliance 
with the corresponding action in this AD.

Definitions

    (l) 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.
    (m) 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.
    (n) 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.
    (o) 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

    (p) 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

    (q) You must use GE 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 incorporation by 
reference of this publication was approved previously by the 
Director of the Federal Register as of August 16, 2004 (69 FR 45562; 
July 30, 2004), 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

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

    Issued in Burlington, Massachusetts, on August 9, 2004.
Ann Mollica,
Acting Manager, Engine and Propeller Directorate, Aircraft 
Certification Service.
[FR Doc. 04-18635 Filed 8-13-04; 8:45 am]
BILLING CODE 4910-13-P