Airworthiness Directives; General Electric Company CF34-1A, -3A, -3A1, -3A2, -3B, and -3B1 Turbofan Engines

[Federal Register Volume 72, Number 66 (Friday, April 6, 2007)]
[Rules and Regulations]
[Pages 16998-17001]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: E7-6345]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2007-27687; Directorate Identifier 2000-NE-42-AD; 
Amendment 39-15012; AD 2007-07-07]
RIN 2120-AA64


Airworthiness Directives; General Electric Company CF34-1A, -3A, 
-3A1, -3A2, -3B, and -3B1 Turbofan Engines

AGENCY: Federal Aviation Administration (FAA), Department of 
Transportation (DOT).

ACTION: Final rule; request for comments.

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SUMMARY: The FAA is superseding an existing airworthiness directive 
(AD) for General Electric Company (GE) CF34-1A, -3A, -3A1, -3A2, -3B, 
and -3B1 turbofan engines. That AD requires a onetime inspection of 
certain fan disks for electrical arc-out indications, replacing fan 
disks with electrical arc-out indications, and reducing the life limit 
of certain fan disks. This AD requires the same reduced life limit of 
certain fan disks, but requires on-wing inspection of certain fan disks 
installed on regional jets within 500 flight hours after the effective 
date of this AD. This AD also requires more enhanced shop-level 
inspections of all fan disks for electrical arc-out defects. This AD 
results from a report that in January 2007, a CF34-3B1 turbofan engine 
experienced an uncontained fan disk failure during flight operation. We 
are issuing this AD to prevent an uncontained fan disk failure and 
airplane damage.

DATES: Effective April 23, 2007. The Director of the Federal Register 
approved the incorporation by reference of certain publications listed 
in the regulations as of April 23, 2007.
    We must receive any comments on this AD by June 5, 2007.

ADDRESSES: Use one of the following addresses to comment 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 20590-0001.
    <bullet> Fax: (202) 493-2251.
    <bullet> 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.
    Contact General Electric Company via Lockheed Martin Technology 
Services, 10525 Chester Road, Suite C, Cincinnati, Ohio 45215; 
telephone (513) 672-8400; fax (513) 672-8422, for the service 
information identified in this AD.

FOR FURTHER INFORMATION CONTACT: Tara Chaidez, Aerospace Engineer, 
Engine Certification Office, FAA, Engine and Propeller Directorate, 12 
New England Executive Park, Burlington, MA 01803; e-mail: 
[email protected]; telephone (781) 238-7773; fax (781) 238-7199.

SUPPLEMENTARY INFORMATION: On February 24, 2006, the FAA issued AD 
2006-05-04, Amendment 39-14501 (71 FR 10832; March 3, 2006). That AD 
requires a onetime inspection, and if necessary replacement of certain 
fan disks for electrical arc-out defects. That AD also reduces the life 
limit of certain fan disks. That AD was the result of a fan disk crack 
found during a visual inspection as part of routine engine maintenance. 
That condition, if not corrected, could result in an uncontained 
failure of the engine.

Actions Since AD 2006-05-04 was Issued

    Since that AD was issued, a CF34-3B1 turbofan engine experienced an 
uncontained fan disk failure during flight operation, in January 2007. 
An inspection of the recovered segments of the fan disk found an 
electrical arc-out defect at the fracture origin site. The fan disk was 
marked using the electro-chemical etch marking (ECM) procedure during 
engine assembly. If the ECM procedure is performed incorrectly, an arc-
out defect can occur. This arc-out defect, caused during part marking, 
resulted in the uncontained failure.
    The uncontained fan disk failure during flight operation in January 
2007 showed that the inspections in GE Service Bulletin No. CF34-BJ 72-
A0088, Revision 1, dated October 30, 2000 and in GE Alert Service 
Bulletin (ASB) No. CF34-AL 72-A0103, dated August 4, 2000, mandated by 
AD 2006-05-04, are not adequate to find all electrical arc-out defects.
    We issued emergency AD 2007-04-51 on February 16, 2007, and its 
follow-up published version, AD 2007-05-16, on February 28, 2007, to 
perform an enhanced onetime inspection of a high-risk suspect 
population of 31 fan disks. While complying with those ADs, operators 
found indications of additional electrical arc-out defects.
    Because these additional indications of electrical arc-out defects 
validate our concern for the significant risk posed in the remaining 
suspect population of fan disks, we are issuing this final rule; 
request for comments AD. This AD requires an accelerated inspection 
schedule using the improved inspections of the three GE ASBs listed 
below. These ASBs include fluorescent penetrant inspection (FPI), 
tactile and enhanced visual (TEV) inspection, and eddy current 
inspection (ECI) for finding electrical arc-out defects. This 
condition, if not corrected, could result in an uncontained fan disk 
failure and airplane damage.

Relevant Service Information

    We have reviewed and approved the technical contents of GE ASBs No. 
CF34-BJ S/B 72-A0212, Revision 2, dated March 22, 2007, ASB No. CF34-AL 
S/B 72-A0233, Revision 2, dated March 22, 2007, and ASB No. CF34-AL S/B 
72-A0231, dated March 7, 2007. All three ASBs list the affected fan 
disks by serial number and part number. The first two ASBs describe 
procedures for performing FPI, a tactile and TEV inspection, and ECI 
for cracks and electrical arc-out defects. The third ASB describes 
procedures for performing an on-wing TEV inspection of fan disks for 
electrical arc-out defects.

FAA's Determination and Requirements of This AD

    The unsafe condition described previously is likely to exist or 
develop on other GE CF34-1A, -3A, -3A1, -3A2, -3B, and -3B1 turbofan 
engines of the same type design. We are issuing this AD to prevent an 
uncontained fan disk failure and airplane damage. This AD requires on-
wing TEV inspection of fan disks for electrical arc-out defects on fan 
disks installed on regional jets within 500 flight hours after the 
effective date of this AD. This AD also requires for all affected fan 
disks shop-level FPI, enhanced TEV, and ECI inspections for cracks and 
electrical arc-out defects. This AD also carries forward from AD 2006-
05-04 the reduced life limit for certain fan disks. You must use the 
service information described previously to perform the actions 
required by this AD.

[[Page 16999]]

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.

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 send us any written relevant data, 
views, or arguments regarding this AD. Send your comments to an address 
listed under ADDRESSES. Include ``AD Docket No. FAA-2007-27687; 
Directorate Identifier 2000-NE-42-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.

Examining the AD Docket

    You may examine the docket that contains the AD, any comments 
received, and any final disposition in person at the Docket Management 
Facility 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.

Docket Number Change

    We are transferring the docket for this AD to the Docket Management 
System as part of our on-going docket management consolidation efforts. 
The new Docket No. is FAA-2007-27687. The old Docket No. became the 
Directorate Identifier, which is 2000-NE-42-AD. This AD might get 
logged into the DMS docket, ahead of the previously collected documents 
from the old docket file, as we are in the process of sending those 
items to the DMS.

Authority for This Rulemaking

    Title 49 of the United States Code specifies the FAA's authority to 
issue rules on aviation safety. Subtitle I, Section 106, describes the 
authority of the FAA Administrator. Subtitle VII, Aviation Programs, 
describes in more detail the scope of the Agency's authority.
    We are issuing this rulemaking under the authority described in 
Subtitle VII, Part A, Subpart III, Section 44701, ``General 
requirements.'' Under that section, Congress charges the FAA with 
promoting safe flight of civil aircraft in air commerce by prescribing 
regulations for practices, methods, and procedures the Administrator 
finds necessary for safety in air commerce. This regulation is within 
the scope of that authority because it addresses an unsafe condition 
that is likely to exist or develop on products identified in this 
rulemaking action.

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 this AD:
    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.


Sec.  39.13  [Amended]

0
2. The FAA amends Sec.  39.13 by removing Amendment 39-14501 (71 FR 
10832; March 3, 2006), and by adding a new airworthiness directive, 
Amendment 39-15012, to read as follows:

2007-07-07 General Electric Company: Amendment 39-15012. Docket No. 
FAA-2007-27687; Directorate Identifier 2000-NE-42-AD.

Effective Date

    (a) This airworthiness directive (AD) becomes effective April 
23, 2007.

Affected ADs

    (b) This AD supersedes AD 2006-05-04.

Applicability

    (c) This AD applies to General Electric Company (GE) CF34-1A, -
3A, -3A1, -3A2, -3B, and -3B1 turbofan engines, with fan disks part 
numbers (P/Ns) 5921T18G01, 5921T18G09, 5921T18G10, 5921T54G01, 
5922T01G02, 5922T01G04, 5922T01G05, 6020T62G04, 6020T62G05, 
6078T00G01, 6078T57G01, 6078T57G02, 6078T57G03, 6078T57G04, 
6078T57G05, and 6078T57G06 installed. These engines are installed 
on, but not limited to, Bombardier Canadair airplane models CL-600-
2A12, -2B16, and -2B19.

Unsafe Condition

    (d) This AD results from a report that in January 2007, a CF34-
3B1 turbofan engine experienced an uncontained fan disk failure 
during flight operation. We are issuing this AD to prevent an 
uncontained fan disk failure and airplane damage.

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.

Removal of Certain Fan Disks From Service

    (f) For fan disks listed by P/N and SN in the following Table A 
that have fewer than 8,000 cycles-since-new (CSN) on the effective 
date of this AD, replace fan disks before accumulating 8,000 CSN:

[[Page 17000]]



   Table A.--Fan Disks That Require Removal Based on Blended Callouts
------------------------------------------------------------------------
             Disk part No.                       Disk serial No.
------------------------------------------------------------------------
6078T57G02.............................  GAT6306N
6078T00G01.............................  GAT3860G
6078T57G02.............................  GAT1924L
5922T01G04.............................  GAT9599G
6078T57G04.............................  GEE05831
6078T57G04.............................  GEE06612
6078T57G04.............................  GEE06618
6078T57G04.............................  GEE06974
6078T57G04.............................  GEE06980
6078T57G05.............................  GEE143FY
6078T57G05.............................  GEE1453G
6078T57G05.............................  GEE14452
6078T57G05.............................  GEE145NA
6078T57G04.............................  GEE08086
6078T57G04.............................  GEE09287
6078T57G04.............................  GEE09337
6078T57G05.............................  GEE12720
6078T57G05.............................  GEE14214
6078T57G05.............................  GEE142YT
6078T57G05.............................  GEE146GT
------------------------------------------------------------------------

    (g) For fan disks listed in Table A of this AD that have 8,000 
CSN or more on the effective date of this AD, replace the disk 
within 15 days after the effective date of this AD.

Inspections of Fan Disks Installed in Regional Jet Airplanes

    (h) For CF34-3A1 and CF34-3B1 turbofan engines installed on 
Bombardier Canadair CL600-2B19 Regional Jet airplanes:

On-Wing Tactile and Enhanced Visual (TEV) Inspection

    (1) On-wing TEV inspect the fan disks listed by P/N and SN in 
Table 1 of GE Alert Service Bulletin (ASB) No. CF34-AL S/B 72-A0231, 
dated March 7, 2007, using the compliance times specified in the 
following Table B:

   Table B.--Regional Jet On-Wing Fan Disk Inspection Compliance Times
------------------------------------------------------------------------
             For fan disks:                          Inspect:
------------------------------------------------------------------------
(i) That have not had a shop-level       Within 500 flight hours after
 inspection.                              the effective date of this AD.
(ii) That are marked with an asterisk    Within 500 flight hours after
 in Table 1 of GE ASB No. CF34-AL S/B     the effective date of this AD.
 72-A0231, dated March 7, 2007.
------------------------------------------------------------------------

    (2) Use paragraphs 3.A. through 3.A.(13) of the Accomplishment 
Instructions of GE ASB No. CF34-AL S/B 72-A0231, dated March 7, 
2007, to do the inspection.

Shop-level Inspection

    (3) Within 5,000 flight hours or 5 calendar years after the 
effective date of this AD, whichever occurs first, fluorescent 
penetrant inspect (FPI), TEV inspect, and eddy current inspect (ECI) 
at shop-level for cracks and electrical arc-out defects on the fan 
disks listed by P/N and SN in Table 1 of GE ASB No. CF34-AL S/B 72-
A0233, Revision 2, dated March 22, 2007.
    (4) Use paragraphs 3.A.(1) through 3.A.(6) of the Accomplishment 
Instructions of GE ASB No. CF34-AL S/B 72-A0233, Revision 2, dated 
March 22, 2007, to do the inspections.

Shop-level Inspection Exemption

    (5) Fan disks are exempt from the shop-level inspection that 
meet the following criteria:
    (i) Fan disks inspected before the effective date of this AD per 
GE Engine Manual No. SEI-756, Section 72-21-00 (FAN ROTOR ASSEMBLY 
INSPECTION); and
    (ii) That have accumulated no more than 100 cycles since that 
inspection; and
    (iii) That pass the on-wing TEV inspection in paragraph (h)(2) 
of this AD.

Inspection of Fan Disks Installed in Business Jet Airplanes

    (i) For CF34-1A, -3A, -3A1, -3A2, and -3B turbofan engines 
installed on Bombardier Canadair Models CL-600-2A12 (CL-601), CL-
600-2B16 (CL-601-3A), (CL-601-3R), and (CL-604) Business Jet 
airplanes:
    (1) FPI, TEV inspect, and ECI for cracks and electrical arc-out 
defects at shop-level on the fan disks listed by P/N and SN in Table 
1 of GE ASB No. CF34-BJ S/B 72-A0212, Revision 2, dated March 22, 
2007, using the compliance times specified in the following Table C:

 Table C.--Business Jet Shop-Level Fan Disk Inspection Compliance Times
------------------------------------------------------------------------
             For fan disks:                          Inspect:
------------------------------------------------------------------------
(i) That have more than 5,500 flight     Within 500 flight hours after
 hours on the effective date of this AD.  the effective date of this AD.
(ii) That have 5,500 or fewer flight     Within accumulating a total of
 hours on the effective date of this AD.  6,000 fan disk operating hours-
                                          since-new, or 5 calendar
                                          years, whichever occurs first.
------------------------------------------------------------------------

    (2) Use paragraphs 3.A. through 3.A.(10) of the Accomplishment 
Instructions of GE ASB No. CF34-BJ S/B 72-A0212, Revision 2, dated 
March 22, 2007, to do the inspections.

Reporting Requirements

    (j) Report the results of the on-wing inspections performed in 
paragraph (h)(2) by following the instructions in paragraph 3.A.(14) 
of the Accomplishment Instructions of GE ASB No. CF34-AL S/B 72-
A0231, dated March 7, 2007. Under the provisions of the Paperwork 
Reduction Act of 1980 (44 U.S.C. 3501 et seq.), the Office of 
Management and Budget (OMB) has approved the information collection 
requirements contained in this AD, and has assigned OMB Control 
Number 2120-0056.

Previous Credit

    (k) Credit is allowed for fan disks previously shop-level 
inspected using GE ASB No. CF34-AL S/B 72-A0233, dated March 7, 2007 
or Revision 1 of that ASB dated March 16, 2007, or GE ASB No. CF34-
BJ S/B 72-A0212, dated March 7, 2007 or Revision 1 of that ASB dated 
March 16, 2007, before the effective date of this AD.

Alternative Methods of Compliance

    (l) 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.

Related Information

    (m) Emergency AD 2007-04-51 and AD 2007-05-16 also pertain to 
the subject of this AD.

Material Incorporated by Reference

    (n) You must use the General Electric Alert Service Bulletins 
listed in Table D of this AD to perform the inspections required by 
this AD. The Director of the Federal Register approved the 
incorporation by reference of the documents listed in Table D of 
this AD in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. You 
can get a copy from General Electric Company via Lockheed Martin 
Technology Services, 10525 Chester Road, Suite C, Cincinnati, Ohio 
45215; telephone (513) 672-8400; fax (513) 672-8422. You can

[[Page 17001]]

review copies at the FAA, New England Region, Office of the Regional 
Counsel, 12 New England Executive Park, Burlington, MA; 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/cfr/ibr-locations.html.

                                      Table D.--Incorporation by Reference
----------------------------------------------------------------------------------------------------------------
     Alert Service Bulletin No.             Page No.                Revision                     Date
----------------------------------------------------------------------------------------------------------------
CF34-AL S/B 72-A0231...............  All...................  Original..............  March 7, 2007.
Total Pages: 94....................
CF34-AL S/B 72-A0233...............  All...................  2.....................  March 22, 2007
Total Pages: 91....................
CF34-BJ S/B 72-A0212...............  All...................  2.....................  March 22, 2007
Total Pages: 95....................
----------------------------------------------------------------------------------------------------------------


    Issued in Burlington, Massachusetts, on March 30, 2007.
Peter A. White,
Acting Manager, Engine and Propeller Directorate, Aircraft 
Certification Service.
[FR Doc. E7-6345 Filed 4-5-07; 8:45 am]
BILLING CODE 4910-13-P

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