Document ID: FAA-2007-27687-0031
Agency: faa
Document Type: Rule
Title: Airworthiness Directives: General Electric Company CF34-1A, -3A, -3A1, -3A2, -3B, and -3B1 Turbofan Engines
Posted Date: 2009-04-17T04:00Z

[Federal Register: April 17, 2009 (Volume 74, Number 73)]
[Proposed Rules]               
[Page 17799-17802]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr17ap09-13]                         

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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]
RIN 2120-AA64

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

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Supplemental Notice of proposed rulemaking (NPRM); reopening of 
comment period.

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SUMMARY: This notice revises an earlier proposed airworthiness 
directive (AD), and supersedes an existing AD applicable to General 
Electric Company (GE) CF34-1A, -3A, -3A1, -3A2, -3B, and -3B1 turbofan 
engines. This proposed AD reopens the comment period, since we added 
additional requirements based on responses we received. This proposed 
AD would now require:
     Inspecting certain fan disks for electrical arc-out 
indications,
     Removing from service fan disks with electrical arc-out 
indications,
     Performing tactile and enhanced visual (TEV) inspections, 
fluorescent penetrant inspections (FPI), and eddy current inspections 
(ECI) on certain disks that have already had a shop-level inspection, 
and
     Repetitive FPI and ECI on certain fan disks.
    This proposed AD results from an updated risk analysis by GE that 
shows we need to take corrective action that is more stringent. We are 
proposing this AD to prevent an uncontained failure of the fan disk, 
which could result in damage to the airplane.

DATES: We must receive any comments on this proposed AD by June 16, 
2009.

ADDRESSES: Use one of the following addresses to comment on this 
proposed AD.
     Federal eRulemaking Portal: Go to http://
www.regulations.gov and follow the instructions for sending your 
comments electronically.
     Mail: Docket Management Facility, U.S. Department of 
Transportation, 1200 New Jersey Avenue SE., West Building Ground Floor, 
Room W12-140, Washington, DC 20590-0001.
     Hand Delivery: Deliver to Mail address above between 9 
a.m. and 5 p.m., Monday through Friday, except Federal holidays.
     Fax: (202) 493-2251.
    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 proposed 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: 
tara.chaidez@faa.gov; telephone (781) 238-7773; fax (781) 238-7199.

SUPPLEMENTARY INFORMATION:

Comments Invited

    We invite you to send us any written relevant data, views, or 
arguments regarding this proposal. Send your comments to an address 
listed under ADDRESSES. Include ``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 proposed AD. We will 
consider all comments received by the closing date and may amend the 
proposed AD in light of those comments.
    We will post all comments we receive, without change, to http://
www.regulations.gov, including any personal information you provide. We 
will also post a report summarizing each substantive verbal contact 
with FAA personnel concerning this proposed AD. Using the search 
function of the Web site, anyone can find and read the comments in any 
of our dockets, including, if provided, 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).

Examining the AD Docket

    You may examine the AD docket on the Internet at http://
www.regulations.gov; or in person at the Docket Operations office 
between 9 a.m. and 5 p.m., Monday through Friday, except Federal 
holidays. The AD docket contains this proposed AD, the regulatory 
evaluation, any comments received, and other information. The street 
address for the Docket Operations office (telephone (800) 647-5527) is 
the same as the Mail address provided in the ADDRESSES section. 
Comments will be available in the AD docket shortly after receipt.

Discussion

    We proposed to amend 14 CFR part 39 by superseding AD 2007-07-07R1, 
Amendment 39-15179 (72 FR 49183, August 28, 2007). 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. That NPRM was 
prompted by us determining that we inadvertently left out an inspection 
requirement in Table C of AD 2007-07-07R1 to perform a shop inspection 
on disks that have greater than 6,000 flight hours and have already 
undergone a shop inspection. That condition, if not corrected, could 
result in an uncontained fan disk failure and airplane damage. On 
January 18, 2008, we published that proposal as an NPRM in the Federal 
Register (73 FR 3425). That NPRM would have required:
     Replacing certain fan disks installed on regional jets 
within 15 days after the effective date of the proposed AD, and
     On-wing and shop-level inspections of fan disks for 
electrical arc-out defects on fan disks installed on regional jets, and
     Shop-level inspections of fan disks for electrical arc-out 
defects on fan disks installed on business jets.
    Since we issued that NPRM, GE performed an updated risk analysis 
that shows we need to take corrective action that is more stringent 
than that proposed in the NPRM. We also propose to amend 14 CFR part 39 
by superseding AD 2007-05-16, Amendment 39-14977 (72 FR 10054, March 7, 
2007). That AD requires a onetime visual and tactile inspection of 
certain areas of certain P/N and SN fan disks for an arc-out defect, 
within 20 engine flight hours after the effective date of that AD. 
Since we issued that AD, GE has added those SN fan disks to the 
applicable service bulletins for the repetitive inspection requirements 
of this proposed AD.
    Since these changes expand the scope of the originally proposed 
rule, we have determined that it is necessary to reopen the comment 
period to provide additional opportunity for public comment. This 
condition, if not corrected, could result in an uncontained failure of 
the fan disk and damage to the airplane.

[[Page 17800]]

Relevant Service Information

    We have reviewed and approved the technical contents of GE Alert 
Service Bulletins (ASBs) No. CF34-BJ S/B 72-A0212, Revision 04, dated 
October 27, 2008; CF34-BJ S/B 72-A0234, dated October 27, 2008; CF34-BJ 
S/B 72-A0235, dated October 27, 2008; CF34-AL S/B 72-A0233, Revision 
04, dated October 27, 2008; CF34-AL S/B 72-A0252, dated October 27, 
2008; and CF34-AL S/B 72-A0253, dated October 27, 2008. These ASBs list 
the affected fan disks by serial number, part number, and tier, and 
describe procedures for performing TEV inspections, FPI, and ECI for 
cracks and electrical arc-out defects.

FAA's Determination and Requirements of the Proposed AD

    We have evaluated all pertinent information and identified an 
unsafe condition that is likely to exist or develop on other products 
of this same type design. We are proposing this AD, which would require 
initial and repetitive FPI, ECI, and TEV inspections. The proposed AD 
would require you to use the service information described previously 
to perform these actions.

Costs of Compliance

    We estimate that this proposed AD would affect 1,531 engines 
installed on airplanes of U.S. registry. We also estimate that it would 
take about 2 work-hours per engine to perform the proposed on-wing 
inspection on 300 engines, and 4 work-hours per engine to perform the 
proposed shop inspection on 1,531 engines. The average labor rate is 
$80 per work-hour. There are no required parts. Based on these figures, 
we estimate the total cost of the proposed AD to U.S. operators to be 
$537,920.

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 proposed AD would not have federalism 
implications under Executive Order 13132. This proposed AD 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.
    For the reasons discussed above, I certify that the proposed 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. Would 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 regulatory evaluation of the estimated costs to 
comply with this proposed AD. 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.

The Proposed Amendment

    Under the authority delegated to me by the Administrator, the 
Federal Aviation Administration proposes to amend 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. The FAA amends Sec.  39.13 by removing Amendment 39-14977 (72 FR 
10054, March 7, 2007) and Amendment 39-15179 (72 FR 49183, August 28, 
2007), and by adding a new airworthiness directive to read as follows:

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

Comments Due Date

    (a) The Federal Aviation Administration (FAA) must receive 
comments on this airworthiness directive (AD) action by June 16, 
2009.
    (b) This AD supersedes AD 2007-05-16, Amendment 39-14977 and AD 
2007-07-07R1, Amendment 39-15179.

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 an updated risk analysis by GE that 
shows we need to take corrective action that is more stringent. We 
are issuing this AD to prevent an uncontained failure of the fan 
disk, which could result in damage to the airplane.

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.

Removing Certain Fan Disks from Service

    (f) For fan disks listed by P/N and serial number (SN) in Table 
2 of GE Alert Service Bulletin (ASB) CF34-BJ S/B 72-A0212, Revision 
04, dated October 27, 2008; or in Table 2 of GE ASB CF34-AL S/B 72-
A0233, Revision 04, dated October 27, 2008 that have 8,000 CSN or 
more on the effective date of this AD, remove fan disks from service 
within 15 days after the effective date of this AD.
    (g) For fan disks listed by P/N and serial number (SN) in Table 
2 of GE Alert Service Bulletin (ASB) CF34-BJ S/B 72-A0212, Revision 
04, dated October 27, 2008; or in Table 2 of GE ASB CF34-AL S/B 72-
A0233, Revision 04, dated October 27, 2008, that have fewer than 
8,000 CSN on the effective date of this AD, remove fan disks from 
service before accumulating 8,000 CSN.

Inspections of Tier 1 Fan Disks

    (h) For CF34-3A1 engines with fan drive shaft, P/N 6036T78P02, 
and airworthiness limitation section life limit of 22,000 CSN, and 
CF34-3B1 turbofan engines with Tier 1 fan disks listed by P/N, SN, 
and Tier in Table 1 of GE ASB No. CF34-AL S/B 72-A0233, Revision 04, 
dated October 27, 2008, do the following:

Tactile and Enhanced Visual (TEV) Inspections, Fluorescent Penetrant 
Inspections (FPI), and Eddy Current Inspections (ECI)

    (1) For Tier 1 fan disks not already inspected using GE ASB No. 
CF34-AL S/B 72-A0233, Revision 03, dated June 27, 2007, or earlier 
issue, do the following:
    (i) Perform a TEV inspection, an FPI, and an ECI on the Tier 1 
fan disks within 650 cycles-in-service (CIS) after the effective 
date of this AD. Use paragraph 3.A of the Accomplishment 
Instructions of GE ASB CF34-AL S/B 72-A0233, Revision 04, dated

[[Page 17801]]

October 27, 2008, to perform the TEV inspection, FPI, and ECI.
    (ii) Thereafter, perform repetitive ECI on the Tier 1 fan disks 
within intervals of 3,000 cycles-since-last inspection (CSLI). Use 
paragraph 3.A of the Accomplishment Instructions of GE ASB CF34-AL 
S/B 72-A0252, dated October 27, 2008, to perform the repetitive ECI.
    (2) For Tier 1 fan disks, listed by P/N, SN, and Tier in Table 1 
of GE ASB No. CF34-AL S/B 72-A0233, Revision 04, dated October 27, 
2008; already inspected using GE ASB No. CF34-AL S/B 72-A0233, 
Revision 03, dated June 27, 2007, or earlier issue, do the 
following:
    (i) For Tier 1 fan disks with 2,500 or more CSLI on the 
effective date of this AD, perform an ECI on the Tier 1 fan disks 
within 500 CIS after the effective date of this AD. Use paragraph 
3.A of the Accomplishment Instructions of GE ASB CF34-AL S/B 72-
A0252, dated October 27, 2008, to perform the ECI.
    (ii) For Tier 1 fan disks with fewer than 2,500 CSLI on the 
effective date of this AD, perform an ECI on the Tier 1 fan disks 
within 3,000 CSLI. Use paragraph 3.A of the Accomplishment 
Instructions of GE ASB CF34-AL S/B 72-A0252, dated October 27, 2008, 
to perform the ECI.
    (iii) Thereafter, perform repetitive ECI on the Tier 1 fan disks 
within intervals of 3,000 CSLI. Use paragraph 3.A of the 
Accomplishment Instructions of GE ASB CF34-AL S/B 72-A0252, dated 
October 27, 2008, to perform the repetitive ECI.

Inspections of Tier 2 Fan Disks

    (i) For CF34-3A1 engines with fan drive shaft, P/N 6036T78P02, 
and airworthiness limitation section life limit of 22,000 CSN, and 
CF34-3B1 turbofan engines with Tier 2 fan disks listed by P/N, SN, 
and Tier in Table 1 of GE ASB No. CF34-AL S/B 72-A0233, Revision 04, 
dated October 27, 2008, do the following:

TEV Inspections, FPI, and ECI

    (1) For Tier 2 fan disks not already inspected using GE ASB No. 
CF34-AL S/B 72-A0233, Revision 03, dated June 27, 2007, or earlier 
issue, do the following:
    (i) Perform a TEV inspection, an FPI, and an ECI on the Tier 2 
fan disks within 2,000 CIS after the effective date of this AD, or 
within 5,000 CIS after September 12, 2007, or by March 19, 2012, 
whichever occurs first. Use paragraph 3.A of the Accomplishment 
Instructions of GE ASB CF34-AL S/B 72-A0233, Revision 04, dated 
October 27, 2008, to perform the TEV inspection, FPI, and ECI.
    (ii) Thereafter, perform repetitive eddy current inspections on 
the Tier 2 fan disks within intervals of 3,000 CSLI. Use paragraph 
3.A of the Accomplishment Instructions of GE ASB CF34-AL S/B 72-
A0252, dated October 27, 2008, to perform the repetitive ECI.
    (2) For Tier 2 fan disks, listed by P/N, SN, and Tier in Table 1 
of GE ASB No. CF34-AL S/B 72-A0233, Revision 04, dated October 27, 
2008; already inspected using GE ASB No. CF34-AL S/B 72-A0233, 
Revision 03, dated June 27, 2007, or earlier issue, do the 
following:
    (i) For Tier 2 fan disks with 2,500 or more CSLI on the 
effective date of this AD, perform an ECI on the Tier 2 fan disks 
within 500 CIS after the effective date of this AD. Use paragraph 
3.A of the Accomplishment Instructions of GE ASB CF34-AL S/B 72-
A0252, dated October 27, 2008, to perform the ECI.
    (ii) For Tier 2 fan disks with fewer than 2,500 CSLI on the 
effective date of this AD, perform an ECI on the Tier 2 fan disks 
within 3,000 CSLI. Use paragraph 3.A of the Accomplishment 
Instructions of GE ASB CF34-AL S/B 72-A0252, dated October 27, 2008, 
to perform the ECI.
    (iii) Thereafter, perform repetitive ECI on the Tier 2 fan disks 
within intervals of 3,000 CSLI. Use paragraph 3.A of the 
Accomplishment Instructions of GE ASB CF34-AL S/B 72-A0252, dated 
October 27, 2008, to perform the repetitive ECI.

Inspections of Tier 3 Fan Disks

    (j) For CF34-3A1 engines with fan drive shaft, P/N 6036T78P02, 
and airworthiness limitation section life limit of 22,000 CSN, and 
CF34-3B1 turbofan engines with Tier 3 fan disks, listed by P/N, SN, 
and Tier in Table 1 of GE ASB No. CF34-AL S/B 72-A0233, Revision 04, 
dated October 27, 2008, do the following:

TEV Inspections, FPI, and ECI

    (1) For Tier 3 fan disks not already inspected using GE ASB No. 
CF34-AL S/B 72-A0233, Revision 03, dated June 27, 2007, or earlier 
issue, perform a TEV inspection, an FPI, and an ECI on the Tier 3 
fan disks within 5,000 CIS after September 12, 2007, or by March 19, 
2012, whichever is earlier. Use paragraph 3.A of the Accomplishment 
Instructions of GE ASB CF34-AL S/B 72-A0253, Revision 04, dated 
October 27, 2008, to perform the TEV inspection, FPI, and ECI.
    (2) For Tier 3 fan disks, listed by P/N, SN, and Tier in Table 1 
of GE ASB No. CF34-AL S/B 72-A0233, Revision 04, dated October 27, 
2008; already inspected using GE ASB No. CF34-AL S/B 72-A0233, 
Revision 03, dated June 27, 2007, or earlier issue, perform a TEV 
inspection and an ECI on the Tier 3 fan disks at the next shop 
visit. Use paragraph 3.A of the Accomplishment Instructions of GE 
ASB CF34-AL S/B 72-A0253, dated October 27, 2008, to perform the TEV 
inspection and ECI.
    (3) Repetitive ECI on the Tier 3 fan disks are not required.

Inspections of Tier 1 Fan Disks

    (k) For CF34-1A turbofan engines with fan drive shaft, P/N 
6036T78P02, and airworthiness limitation section life limit of 
15,000 CSN, CF34-3A, CF34-3A2, and CF34-3B turbofan engines with 
Tier 1 fan disks listed by P/N, SN, and Tier in Table 1 of GE ASB 
No. CF34-BJ S/B 72-A0212, Revision 04, dated October 27, 2008, do 
the following:

TEV Inspections, FPI, and ECI

    (1) For Tier 1 fan disks not already inspected using GE ASB No. 
CF34-BJ S/B 72-A0212, Revision 03, dated June 27, 2007, or earlier 
issue:
    (i) Perform a TEV inspection, FPI, and ECI on the Tier 1 fan 
disks within 350 CIS after the effective date of this AD. Use 
paragraph 3.A of the Accomplishment Instructions of GE ASB CF34-BJ 
S/B 72-A0212, Revision 04, dated October 27, 2008, to perform the 
TEV inspection.
    (ii) Thereafter, perform repetitive ECI on the Tier 1 fan disks 
within intervals of 3,000 CSLI. Use paragraph 3.A of the 
Accomplishment Instructions of GE ASB CF34-BJ S/B 72-A0235, dated 
October 27, 2008, to perform the repetitive ECI.
    (2) For Tier 1 fan disks, listed by P/N, SN, and Tier in Table 1 
of GE ASB No. CF34-BJ S/B 72-A0212, Revision 04, dated October 27, 
2008; already inspected using GE ASB No. CF34-BJ S/B 72-A0212, 
Revision 03, dated June 27, 2007, or earlier issue, do the 
following:
    (i) For Tier 1 fan disks with 2,500 or more CSLI on the 
effective date of this AD, perform an ECI on the Tier 1 fan disks 
within 500 CIS after the effective date of this AD. Use paragraph 
3.A of the Accomplishment Instructions of GE ASB CF34-BJ S/B 72-
A0235, dated October 27, 2008, to perform the ECI.
    (ii) For Tier 1 fan disks with fewer than 2,500 CSLI on the 
effective date of this AD, perform an ECI on the Tier 1 fan disks 
within 3,000 CSLI after the effective date of this AD. Use paragraph 
3.A of the Accomplishment Instructions of GE ASB CF34-BJ S/B 72-
A0235, dated October 27, 2008, to perform the ECI.
    (iii) Thereafter, perform repetitive ECI on the Tier 1 fan disks 
within intervals of 3,000 CSLI. Use paragraph 3.A of the 
Accomplishment Instructions of GE ASB CF34-AL S/B 72-A0235, dated 
October 27, 2008, to perform the repetitive ECI.

Inspections of Tier 2 Fan Disks

    (l) For CF34-1A turbofan engines with fan drive shaft, P/N 
6036T78P02, and airworthiness limitation section life limit of 
15,000 CSN, CF34-3A, CF34-3A2, and CF34-3B turbofan engines with 
Tier 2 fan disks listed by P/N, SN, and Tier in Table 1 of GE ASB 
No. CF34-AL S/B 72-A0212, Revision 04, dated October 27, 2008, do 
the following:

TEV Inspections, FPI, and ECI

    (1) For Tier 2 fan disks not already inspected using GE ASB No. 
CF34-AL S/B 72-A0212, Revision 03, dated June 27, 2007, or earlier 
issue, do the following:
    (i) Perform a TEV inspection, FPI, and ECI on the Tier 2 fan 
disks within 2,000 CIS after the effective date of this AD, or 
within 3,500 CIS after September 12, 2007, or by March 19, 2012, 
whichever occurs first. Use paragraph 3.A of the Accomplishment 
Instructions of GE ASB CF34-BJ S/B 72-A0212, Revision 04, dated 
October 27, 2008, to perform the TEV inspection, FPI, and ECI.
    (ii) Thereafter, perform repetitive ECI on the Tier 2 fan disks 
within intervals of 3,000 CSLI. Use paragraph 3.A of the 
Accomplishment Instructions of GE ASB CF34-BJ S/B 72-A0235, dated 
October 27, 2008, to perform the repetitive ECI.
    (2) For Tier 2 fan disks, listed by P/N, SN, and Tier in Table 1 
of GE ASB No. CF34-BJ S/B 72-A0212, Revision 04, dated October 27, 
2008; already inspected using GE ASB

[[Page 17802]]

No. CF34-BJ S/B 72-A0212, Revision 03, dated June 27, 2007, or 
earlier issue, do the following:
    (i) For Tier 2 fan disks with 2,500 or more CSLI on the 
effective date of this AD, perform an ECI on the Tier 2 fan disks 
within 500 CIS after the effective date of this AD. Use paragraph 
3.A of the Accomplishment Instructions of GE ASB CF34-BJ S/B 72-
A0235, dated October 27, 2008, to perform the ECI.
    (ii) For Tier 2 fan disks with fewer than 2,500 CSLI on the 
effective date of this AD, perform an ECI on the Tier 2 fan disks 
within 3,000 CSLI. Use paragraph 3.A of the Accomplishment 
Instructions of GE ASB CF34-BJ S/B 72-A0235, dated October 27, 2008, 
to perform the ECI.
    (iii) Thereafter, perform repetitive ECI on the Tier 2 fan disks 
within intervals of 3,000 CSLI. Use paragraph 3.A of the 
Accomplishment Instructions of GE ASB CF34-BJ S/B 72-A0235, dated 
October 27, 2008, to perform the repetitive ECI.

Inspections of Tier 3 Fan Disks

    (m) For CF34-1A turbofan engines with fan drive shaft, P/N 
6036T78P02, and airworthiness limitation section life limit of 
15,000 CSN, CF34-3A, CF34-3A2, and CF34-3B turbofan engines with 
Tier 3 fan disks listed by P/N, SN, and Tier in Table 1 of GE ASB 
No. CF34-BJ S/B 72-A0212, Revision 04, dated October 27, 2008, do 
the following:

TEV Inspections, FPI, and ECI

    (1) For Tier 3 fan disks not already inspected using GE ASB No. 
CF34-AL S/B 72-A0212, Revision 03, dated June 27, 2007, or earlier 
issue, perform a TEV inspection, FPI, and ECI on the Tier 3 fan 
disks within 3,500 CIS after September 12, 2007, or by March 19, 
2012, whichever is earlier. Use paragraph 3.A of the Accomplishment 
Instructions of GE ASB CF34-AL S/B 72-A0234, dated October 27, 2008, 
to perform the TEV inspection, FPI, and ECI.
    (2) For Tier 3 fan disks, listed by P/N, SN, and Tier in Table 1 
of GE ASB No. CF34-BJ S/B 72-A0212, Revision 04, dated October 27, 
2008; already inspected using GE ASB No. CF34-BJ S/B 72-A0212, 
Revision 03, dated June 27, 2007, or earlier issue, perform a TEV 
inspection and an ECI on the Tier 3 fan disks within 3,500 CSLI, but 
no later than March 19, 2012. Use paragraph 3.A of the 
Accomplishment Instructions of GE ASB CF34-BJ S/B 72-A0234, dated 
October 27, 2008, to perform the TEV inspection and ECI.
    (3) Repetitive ECI on the Tier 3 fan disks are not required.

Alternative Methods of Compliance

    (n) 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.

Mandatory Terminating Action

    (o) Remove from service, Tier 1 and Tier 2 fan disks listed by 
P/N, SN, and Tier in Table 1 of GE ASB No. CF34-AL S/B 72-A0233, 
Revision 04, dated October 27, 2008; or CF34-BJ S/B 72-0212, 
Revision 04, dated October 27, 2008, before they exceed their 
limited life cycles or September 30, 2018, whichever occurs first.

Related Information

    (p) Contact Tara Chaidez, Aerospace Engineer, Engine 
Certification Office, FAA, Engine and Propeller Directorate, 12 New 
England Executive Park, Burlington, MA 01803; e-mail: 
tara.chaidez@faa.gov; telephone (781) 238-7773; fax (781) 238-7199, 
for more information about this AD.
    (q) The following GE Alert Service Bulletins pertain to the 
subject of this AD:
     CF34-AL S/B 72-A0233, Revision 04, dated October 27, 
2008,
     CF34-AL S/B 72-A0252, dated October 27, 2008,
     CF34-AL S/B 72-A0253, dated October 27, 2008,
     CF34-BJ S/B 72-A0212, Revision 04, dated October 27, 
2008,
     CF34-BJ S/B 72-A0234, dated October 27, 2008, and
     CF34-BJ S/B 72-A0235, dated October 27, 2008.
    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 a copy of this 
service information.

    Issued in Burlington, Massachusetts, on April 9, 2009.
Peter A. White,
Assistant Manager, Engine and Propeller Directorate, Aircraft 
Certification Service.
[FR Doc. E9-8787 Filed 4-16-09; 8:45 am]

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