Airworthiness Directives; General Electric Company CF6-50C Series Turbofan Engines

[Federal Register Volume 72, Number 104 (Thursday, May 31, 2007)]
[Rules and Regulations]
[Pages 30249-30251]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: E7-10316]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2006-24171; Directorate Identifier 2006-NE-08-AD; 
Amendment 39-15075; AD 2007-11-18]
RIN 2120-AA64


Airworthiness Directives; General Electric Company CF6-50C Series 
Turbofan Engines

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

ACTION: Final rule.

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SUMMARY: The FAA is adopting a new airworthiness directive (AD) for 
certain General Electric Company (GE) CF6-50C series turbofan engines. 
This AD requires reworking certain forward fan stator cases and 
installing a fan module secondary containment shield. This AD results 
from reports of uncontained fan blade failures causing damage and 
separation of airplane hydraulic lines. We are issuing this AD to 
prevent uncontained fan blade failures, which can result in separation 
of airplane hydraulic lines, damage to critical airplane systems, and 
possible loss of airplane control.

DATES: This AD becomes effective July 5, 2007. The Director of the 
Federal Register approved the incorporation by reference of certain 
publications listed in the regulations as of July 5, 2007.

ADDRESSES: You can get the service information identified in this AD 
from General Electric Company via GE-Aviation, Attn: Distributions, 111 
Merchant St., Room 230, Cincinnati, Ohio 45246, telephone (513) 552-
3272; fax (513) 552-3329.
    You may examine the AD docket on the Internet at http://dms.dot.gov 
or in Room PL-401 on the plaza level of the Nassif Building, 400 
Seventh Street, SW., Washington, DC.

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: The FAA proposed to amend 14 CFR part 39 
with a proposed AD. The proposed AD applies to GE CF6-50C series 
turbofan engines. We published the proposed AD in the Federal Register 
on April 17, 2006 (71 FR 19661). That action proposed to require 
reworking certain forward fan stator cases and installing a fan module 
secondary containment shield.

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.

Comments

    We provided the public the opportunity to participate in the 
development of this AD. We have considered the comments received.

Reworked and Re-Identified Fan Stator Cases

    A private citizen states that some fan stator cases with certain 
part numbers (P/Ns) listed in the proposed AD might have been be 
reworked and re-identified to different P/Ns, per GE Service Bulletin 
(SB) No. CF6-50 S/B 72-0277. The commenter feels that the rework P/Ns 
should also be listed in the AD.
    We agree. We added P/Ns 9173M37G01, G02, G03, G04, G05, and G06 to 
the list of affected fan stator cases in the AD.

Updated Service Bulletin

    Since we issued the proposed AD, GE issued Revision 2 to the SBs 
incorporated by reference in this AD. These revisions contain minor 
formatting changes to the text,

[[Page 30250]]

incorporate improved illustrations, and add fan stator case P/Ns. We 
want operators to use the Revision 2 SBs. We removed the incorporations 
by reference to the original, and Revision 1 of the SBs that appeared 
in the proposed AD and incorporated by reference Revision 2 of the SBs 
into this AD.

Compliance Date Is Not Justified by the Risk

    FedEx Express states that the proposed AD compliance date of no 
later than June 30, 2007, is not consistent with the historical 
importance associated with this design deficiency. They reference GE 
CF6-50 engine Service Bulletin No. 72-0986, issued in 1991 and revised 
in 1998, which contain GE's recommended compliance of ``at operator 
convenience''. FedEx Express states that they feel this recommendation 
is consistent with their fan blade separation service experience, of 
never having an event of uncontained fan blades on the CF6-50C engine. 
FedEx Express further states that they feel that this current 
regulatory action is only in response to a test cell incident from 
April 2003. They suggest that this compliance date would create an 
unnecessary operational and financial burden. FedEx Express requests 
that the proposed AD action be done only at next engine shop visit.
    We partially agree. We reviewed our risk assessment and found that 
the risk can be managed by extending the compliance date three years. 
We changed the AD compliance date to no later than June 30, 2010.
    We do not agree with eliminating the compliance date. This AD 
results from six reported fan uncontainment events with hydraulic line 
damage that occurred during aircraft operation. This is the safety 
concern we are addressing in this AD. We did not eliminate the 
compliance date from the AD.

Conclusion

    We have carefully reviewed the available data, including the 
comments received, and determined that air safety and the public 
interest require adopting the AD with the changes described previously. 
We have determined that these changes will neither increase the 
economic burden on any operator nor increase the scope of the AD.

Costs of Compliance

    We estimate that this AD will affect 226 CF6-50C series turbofan 
engines installed on airplanes of U.S. registry. We also estimate that 
it will take about 2.5 work hours per engine to perform the actions, 
and that the average labor rate is $80 per work-hour. Required parts 
will cost about $9,451 per engine. Based on these figures, we estimate 
the total cost of the AD to U.S. operators to be $2,181,126.

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 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
Accordingly, under the authority delegated to me by the Administrator, 
the Federal Aviation Administration amends 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 adding the following new airworthiness 
directive:

2007-11-18 General Electric Company: Amendment 39-15075. Docket No. 
FAA-2006-24171; Directorate Identifier 2006-NE-08-AD.

Effective Date

    (a) This airworthiness directive (AD) becomes effective July 5, 
2007.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to General Electric Company (GE) CF6-50C, 
CF6-50C1, CF6-50C2, CF6-50C2B, CF6-50C2F, and CF6-50C2R turbofan 
engines, with a forward fan stator case, part number (P/N) 
9064M53G04, GO5, G06, G07, G08, G09, G10, G12, or G13, or P/N 
9173M37G01, G02, G03, G04, G05, or G06 installed. These engines are 
installed on, but not limited to, Airbus A300, McDonnell Douglas DC-
10 series, and DC-10-30F (KC-10A, KDC-10) airplanes.

Unsafe Condition

    (d) This AD results from reports of uncontained fan blade 
failures causing damage and separation of airplane hydraulic lines. 
We are issuing this AD to prevent uncontained fan blade failures, 
which can result in separation of airplane hydraulic lines, damage 
to critical airplane systems, and possible loss of airplane control.

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.
    (f) At the next engine shop visit after the effective date of 
this AD, but no later than June 30, 2010, rework the forward fan 
stator case and install the fan module secondary containment shield.
    (1) For engines on Airbus 300 series airplanes, use paragraph 3, 
Accomplishment Instructions, of GE Service Bulletin (SB) No. CF6-50 
S/B 72-0985, Revision 2, dated March 21, 2007, to do the rework and 
installation.
    (2) For engines on McDonnell Douglas airplanes, use paragraph 3, 
Accomplishment Instructions, of GE SB No. CF6-50 S/B 72-0986, 
Revision 2, dated March 21, 2007, to do the rework and installation.
    (g) The rework and installation specified in paragraphs (f)(1) 
through (f)(2) of this AD can also be done on-wing.

Previous Credit

    (h) Previous credit is allowed for fan stator cases reworked and 
containment shields installed using GE SB No. CF6-50 S/B 72-

[[Page 30251]]

0985, dated December 2, 1991 or Revision 1, dated September 15, 
1998, or GE SB No. CF6-50 S/B 72-0986, dated December 2, 1991 or 
Revision 1, dated September 15, 1998, before the effective date of 
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) European Aviation Safety Agency airworthiness directive 
2004-0007, dated December 15, 2004, also addresses the subject of 
this AD.
    (k) 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.

Material Incorporated by Reference

    (l) You must use the General Electric Company service 
information specified in Table 1 of this AD to perform the rework 
and installations required by this AD. The Director of the Federal 
Register approved the incorporation by reference of the documents 
listed in Table 1 of this AD in accordance with 5 U.S.C. 552(a) and 
1 CFR part 51. 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. You may 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 1.--Incorporation by Reference
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           Service Bulletin No.                      Page            Revision                 Date
----------------------------------------------------------------------------------------------------------------
CF6-50 S/B 72-0985.......................  All....................          2  March 21, 2007.
Total Pages: 13
CF6-50 S/B 72-0986.......................  All....................          2  March 21, 2007.
Total Pages: 13
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    Issued in Burlington, Massachusetts, on May 22, 2007.
Peter A. White,
Acting Manager, Engine and Propeller Directorate, Aircraft 
Certification Service.
[FR Doc. E7-10316 Filed 5-30-07; 8:45 am]
BILLING CODE 4910-13-P

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