[Federal Register Volume 73, Number 13 (Friday, January 18, 2008)]
[Proposed Rules]
[Pages 3425-3428]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: E8-821]


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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), Department of 
Transportation (DOT).

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: The FAA proposes to supersede an existing airworthiness 
directive (AD) for General Electric Company (GE) CF34-1A, -3A, -3A1, -
3A2, -3B, and -3B1 turbofan engines. That AD currently 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 proposed AD 
would require the same reduced life limit of certain fan disks, on-wing 
inspection of certain fan disks installed on regional jets, and would 
add a requirement to perform an inspection on certain business jet 
applications that have already had a shop-level inspection. This 
proposed AD results from us determining that we inadvertently left out 
an inspection requirement. We are proposing this AD to prevent 
uncontained fan disk failure and airplane damage.

DATES: We must receive any comments on this proposed AD by March 18, 
2008.

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: 
[email protected]; telephone (781) 238-7773; fax (781) 238-7199.

SUPPLEMENTARY INFORMATION:

Comments Invited

    We invite you to send 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

[[Page 3426]]

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

    The FAA proposes 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 AD 
was the result of GE revising their service information and a comment 
from an operator asking us to clarify Table C of this AD. That 
condition, if not corrected, could result in an uncontained fan disk 
failure and airplane damage.

Actions Since AD 2007-07-07R1 Was Issued

    Since we issued that AD, we determined that we inadvertently left 
out an inspection requirement in Table C of that AD to perform a shop 
inspection on disks that have greater than 6,000 flight hours and have 
already undergone a shop inspection.

Relevant Service Information

    We have reviewed and approved the technical contents of GE ASB No. 
CF34-BJ S/B 72-A0212, Revision 3, dated June 27, 2007, ASB No. CF34-AL 
S/B 72-A0233, Revision 3, dated June 27, 2007, and ASB No. CF34-AL S/B 
72-A0231, Revision 1, dated June 27, 2007. All three ASBs list the 
affected fan disks by serial number and part number. The first two ASBs 
describe procedures for performing fluorescent penetrant inspection 
(FPI), a Tactile and Enhanced Visual (TEV) inspection, and eddy current 
inspection (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. For that reason, we are proposing this 
AD to prevent an uncontained fan disk failure and airplane damage. This 
proposed AD would require:
     Replacing certain fan disks installed on regional jets 
within 15 days after the effective date of this proposed AD, and
     On-wing and shop-level inspections of fan disks for 
electrical arc-out defects on fan disks installed on regional jets.
     Shop-level inspections of fan disks for electrical arc-out 
defects on fan disks installed on business jets.
    You must use the service information described previously to 
perform the actions required by this AD.

Costs of Compliance

    We estimate that this proposed AD would affect 1,727 engines 
installed on airplanes of U.S. registry. We also estimate that it would 
take about 6.0 work-hours per engine to perform the proposed actions, 
and that 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 $828,960.

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. See the ADDRESSES section for a location 
to examine the regulatory evaluation.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, 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 39-15179 (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 March 18, 
2008.

Affected ADs

    (b) This AD supersedes 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 us determining that we inadvertently 
left out an inspection requirement. We are issuing this AD to 
prevent 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.

[[Page 3427]]

Removal of Certain Fan Disks From Service

    (f) For fan disks listed by P/N and serial number (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:

   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) Perform an on-wing TEV inspection on the fan disks listed by 
P/N and SN in Table 1 of GE ASB No. CF34-AL S/B 72-A0231, Revision 
1, dated June 27, 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.                              September 12, 2007.
(ii) That are marked with an asterisk    Within 500 flight hours after
 in Table 1 of GE ASB No. CF34-AL S/B     September 12, 2007.
 72-A0231, Revision 1, dated June 27,
 2007.
------------------------------------------------------------------------

    (2) Use paragraphs 3.A. through 3.A.(13) of the Accomplishment 
Instructions of GE ASB No. CF34-AL S/B 72-A0231, Revision 1, dated 
June 27, 2007, to do the inspection.

Shop-Level Inspection

    (3) Within 5,000 flight hours or by September 12, 2012, 
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 3, dated June 
27, 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 3, dated 
June 27, 2007, to do the inspections.

Shop-Level Inspection Exemption

    (5) Fan disks that meet the following criteria are exempt from 
the shop-level inspection:
    (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 3, dated June 27, 
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 not had a shop-level       Within 500 flight hours after
 inspection and have more than 5,500      September 12, 2007.
 flight hours on September 12, 2007.
(ii) That have not had a shop-level      Within accumulating a total of
 inspection and have 5,500 or fewer       6,000 fan disk operating hours-
 flight hours on the effective date of    since-new or by September 12,
 this AD.                                 2012, whichever occurs first.
(iii) That have had a shop-level         Within accumulating an
 inspection.                              additional 6,000 fan disk
                                          operating hours-since-shop-
                                          level inspection, or by
                                          September 12, 2012, 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 3, dated 
June 27, 2007, to do the inspections.

Reporting Requirements

    (j) 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.
    (1) Report the results of the on-wing inspections performed in 
paragraph (h)(2) of this AD by following the instructions in 
paragraph 3.A.(14) of the Accomplishment Instructions of GE ASB No. 
CF34-AL S/B 72-A0231, Revision 1, dated June 27, 2007.
    (2) Report the results of the shop-level inspections performed 
in paragraph (h)(4) of this AD by following the instructions in 
paragraph 3.A.(3)(b)11 of the Accomplishment Instructions of GE ASB 
No. CF34-AL S/B 72-A0233, Revision 3, dated June 27, 2007.
    (3) Report the results of the shop-level inspections performed 
in paragraph (i)(2) of this AD by following the instructions in 
paragraph 3.A.(3)(b)11 of the Accomplishment Instructions of GE ASB 
No. CF34-AL S/B 72-A0212, Revision 3, dated June 27, 2007.

Previous Credit

    (k) We are allowing previous credit for:
    (1) Fan disks previously shop-level inspected before the 
effective date of this AD using GE ASB No. CF34-AL S/B 72-A0233,

[[Page 3428]]

dated March 7, 2007, Revision 1, dated March 16, 2007, or Revision 
2, dated March 22, 2007; and GE ASB No. CF34-BJ S/B 72-A0212, dated 
March 7, 2007, Revision 1, dated March 16, 2007, or Revision 2, 
dated March 22, 2007.
    (2) Fan disks previously on-wing TEV inspected before the 
effective date of this AD using GE ASB No. CF34-AL S/B 72-A0231, 
dated March 7, 2007.

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.
    (n) GE Alert Service Bulletins ASB No. CF34-BJ S/B 72-A0212, 
Revision 3, dated June 27, 2007; ASB No. CF34-AL S/B 72-A0233, 
Revision 3, dated June 27, 2007; and ASB No. CF34-AL S/B 72-A0231, 
Revision 1, dated June 27, 2007; pertain to the subject of this AD.
    (o) 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, 
for more information about this AD.

    Issued in Burlington, Massachusetts, on January 10, 2008.
Peter A. White,
Assistant Manager, Engine and Propeller Directorate, Aircraft 
Certification Service.
 [FR Doc. E8-821 Filed 1-17-08; 8:45 am]
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