
[Federal Register: November 26, 2008 (Volume 73, Number 229)]
[Proposed Rules]               
[Page 71949-71951]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr26no08-26]                         

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2008-1025; Directorate Identifier 2008-NE-31-AD]
RIN 2120-AA64

 
Airworthiness Directives; General Electric Company CF6-80C2 and 
CF6-80E1 Series 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 adopt a new airworthiness directive (AD) 
for General Electric Company (GE) CF6-80C2 and CF6-80E1 series turbofan 
engines with high-pressure compressor rotor (HPCR) spool shaft stage 14 
disks, part number (P/N) 1703M49G02, 1703M49G03, or 1509M71G10 
installed. This proposed AD would require a one-time eddy current 
inspection (ECI) of the HPCR spool shaft stage 14 disk web for crack 
indications, and removing from service any parts with web cracks. This 
proposed AD results from reports of 12 HPCR spool shaft stage 14 disks 
with web cracks discovered to date. We are proposing this AD to prevent 
cracks from propagating to an uncontained failure of the disk and 
damage to the airplane.

DATES: We must receive any comments on this proposed AD by January 26, 
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.
    You can get the service information identified in this proposed AD 
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.

FOR FURTHER INFORMATION CONTACT: Christopher Richards, Aerospace 
Engineer, Engine Certification Office, FAA, Engine & Propeller 
Directorate, 12 New England Executive Park, Burlington, MA 01803; e-
mail: christopher.j.richards@faa.gov; telephone (781) 238-7133; 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-2008-1025; Directorate 
Identifier 2008-NE-31-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

    Since July 2001, GE has reported 12 HPCR spool shaft stage 14 disks 
with web cracks that were installed in CF6-80C2 and CF6-80E1 series 
turbofan engines. GE determined that the cracks were caused by defects 
created during the manufacturing process as a result of high amplitude 
fatigue (HAF). Although the parts were fluorescent penetrant inspected 
(FPI) during manufacture, the FPI did not detect the cracks. GE has 
since revised their manufacturing process to eliminate the HAF. Failure 
to inspect each affected HPCR spool shaft stage 14 disk web for cracks 
could result in uncontained failure of the disk and damage to the 
airplane.

Relevant Service Information

    We have reviewed and approved the technical contents of GE Alert 
Service Bulletin (ASB) No. CF6-80C2 S/B 72-A1122, Revision 1, dated 
June 19, 2006 (CF6-80C2 series engines), and GE ASB No. CF6-80E1 S/B 
72-A0258, Revision 1, dated June 15, 2006 (CF6-80E1 series engines). 
Those ASBs describe procedures for performing a one-time ECI of the 
HPCR spool shaft stage 14 disk web for crack indications.

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, at the next engine shop visit where the separation of a major 
engine flange will occur, a one-time ECI of the HPCR spool shaft stage 
14 disk web for crack indications, and removal from service of parts 
found cracked. The proposed AD would require you to use the service 
information described previously to perform these actions.

[[Page 71950]]

Costs of Compliance

    We estimate that this proposed AD would affect 126 CF6-80C2 and 
CF6-80E1 series turbofan engines installed on airplanes of U.S. 
registry. We also estimate that it would take about 10 work-hours per 
engine to perform the inspection, and about 281 hours to complete the 
proposed actions if done at module level, and that the average labor 
rate is $80 per work-hour. The pro-rated cost of a HPCR stage 10-14 
spool shaft, based on average life remaining on disks found cracked, is 
$526,890. Using data on the percentage of the affected fleet already in 
compliance with the corrective actions, we estimate there will be 10 
disks found cracked as a result of these inspections. Based on these 
figures, we estimate the total cost of the proposed AD to U.S. 
operators to be $594,500.

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 adding the following new 
airworthiness directive:

General Electric Company: Docket No. FAA-2008-1025; Directorate 
Identifier 2008-NE-31-AD.

Comments Due Date

    (a) The Federal Aviation Administration (FAA) must receive 
comments on this airworthiness directive (AD) action by January 26, 
2009.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to General Electric Company (GE) CF6-80C2 
and CF6-80E1 series turbofan engines with high-pressure compressor 
rotor (HPCR) spool shaft stage 14 disks part number (P/N) 
1703M49G02, 1703M49G03, or 1509M71G10 installed. These engines are 
installed on, but not limited to, Airbus A300-600R/F, A310-200/300, 
and A330-200/300, and Boeing 747-300/400/400ER, 767-200/200ER/300/
300ER/400ER and MD-11 airplanes.

Unsafe Condition

    (d) This AD results from reports of 12 cracked HPCR spool shaft 
stage 14 disk webs discovered to date. We are issuing this AD to 
prevent cracks from propagating to an uncontained failure of the 
disk and damage to the airplane.

Compliance

    (e) You are responsible for having the actions required by this 
AD performed at the next engine shop visit where the separation of a 
major engine flange will occur after the effective date of this AD, 
unless the actions have already been done.
    (f) For the purpose of this AD, introduction of an engine into a 
shop solely for the following maintenance actions is not considered 
an engine shop visit:
    (1) Removal of a compressor case for airfoil or variable stator 
vane bushing maintenance.
    (2) Removal or replacement of the stage 1 fan disk.
    (3) Replacement of the turbine rear frame.
    (4) Removal or replacement of the accessory and/or transfer 
gearbox.
    (5) Removal or replacement of the fan forward case.
    (6) Any combination of the maintenance actions listed above.

One-Time Eddy Current Inspection (ECI)

    (g) Using the following Alert Service Bulletin (ASB) 
instructions, perform a one-time ECI of the HPCR spool shaft stage 
14 disk web for crack indications, and remove from service those 
parts found to be cracked.
    (1) Use paragraphs 3.B.(1) through 3.B.(5) of the Accomplishment 
Instructions of GE ASB No. CF6-80C2 S/B 72-A1122, Revision 1, dated 
June 19, 2006, to ECI the CF6-80C2 series engine HPCR spool shaft 
stage 14 disk web at the module level.
    (2) Use paragraph 3.C.(1) of the Accomplishment Instructions of 
GE ASB No. CF6-80C2 S/B 72-A1122, Revision 1, dated June 19, 2006, 
to ECI the CF6-80C2 series engine HPCR spool shaft stage 14 disk web 
at the piece-part level.
    (3) Use paragraphs 3.B.(1) through 3.B.(5) of the Accomplishment 
Instructions of GE ASB No. CF6-80E1 S/B 72-A0258, Revision 1, dated 
June 15, 2006, to ECI the CF6-80E1 series engine HPCR spool shaft 
stage 14 disk web at the module level.
    (4) Use paragraph 3.C.(1) of the Accomplishment Instructions of 
GE ASB No. CF6-80E1 S/B 72-A0258, Revision 1, dated June 15, 2006, 
to ECI the HPCR spool shaft stage 14 disk web at the piece-part 
level.

Previous Credit

    (h) Performance of a one-time ECI of the HPCR spool shaft stage 
14 disk web for crack indications, done before the effective date of 
this AD and following the procedures defined in GE ASB No. CF6 80C2 
S/B 72-A1122, dated January 19, 2004, for CF6-80C2 series engines or 
GE ASB No. CF6 80E1 S/B 72-A0258, dated January 19, 2004, for CF6-
80E1 series engines satisfies the compliance requirements specified 
in this AD.

Alternative Methods of Compliance

    (i) 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

    (j) Contact Christopher Richards, Aerospace Engineer, Engine 
Certification Office, FAA, Engine & Propeller Directorate, 12 New 
England Executive Park, Burlington, MA 01803; e-mail: 
christopher.j.richards@faa.gov; telephone (781) 238-7133; fax (781) 
238-7199, for more information about this AD.


[[Page 71951]]


    Issued in Burlington, Massachusetts, on November 18, 2008.
Peter A. White,
Assistant Manager, Engine and Propeller Directorate, Aircraft 
Certification Service.
[FR Doc. E8-28054 Filed 11-25-08; 8:45 am]

BILLING CODE 4910-13-P
