Skip to Content

Rule

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

Document Details

Information about this document as published in the Federal Register.

Published Document

This document has been published in the Federal Register. Use the PDF linked in the document sidebar for the official electronic format.

Start Preamble

AGENCY:

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

ACTION:

Final rule.

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.

Start Further Info

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.

End Further Info End Preamble Start Supplemental Information

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, Start Printed Page 30250incorporate 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.

Start List of Subjects

List of Subjects in 14 CFR Part 39

End List of Subjects

Adoption of the Amendment

Start Amendment Part

Accordingly, under the authority delegated to me by the Administrator, the Federal Aviation Administration amends

End Amendment Part Start Part

PART 39—AIRWORTHINESS DIRECTIVES

End Part Start Amendment Part

1. The authority citation for part 39 continues to read as follows:

End Amendment Part Start Authority

Authority: 49 U.S.C. 106(g), 40113, 44701.

End Authority
[Amended]
Start Amendment Part

2. The FAA amends § 39.13 by adding the following new airworthiness directive:

End Amendment Part

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-Start Printed Page 302510985, 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: tara.chaidez@faa.gov; 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

Service Bulletin No.PageRevisionDate
CF6-50 S/B 72-0985All2March 21, 2007.
Total Pages: 13
CF6-50 S/B 72-0986All2March 21, 2007.
Total Pages: 13
Start Signature

Issued in Burlington, Massachusetts, on May 22, 2007.

Peter A. White,

Acting Manager, Engine and Propeller Directorate, Aircraft Certification Service.

End Signature End Supplemental Information

[FR Doc. E7-10316 Filed 5-30-07; 8:45 am]

BILLING CODE 4910-13-P