On January 15, 2002, the FAA issued AD 2002-01-04, Amendment 39-12595 (67 FR 4326, January 30, 2002). That AD requires flex borescope inspections of HPT S2 NGVs installed in CF6-80E1 model turbofan engines. That AD was the result of an uncontained engine failure attributed to HPT S2 NGV distress. That condition, if not corrected, could result in failure of HPT rotor blades from HPT S2 NGV distress, which could result in an uncontained engine failure.
Actions After AD 2002-01-04 Was Issued
After AD 2002-01-04 was issued, GE received inspection findings of HPT S2 NGVs that show cracks from distress. GE and the FAA have determined that cracks from this distress could occur sooner and propagate faster than originally predicted, and have also determined that the inspection compliance intervals of AD 2002-01-04 are too long.
Relevant Service Information
We have reviewed and approved the technical contents of GE Service Bulletin (SB) No. CF6-80E1 S/B 72-0217, Revision 2, dated January 5, 2004, that describes procedures for initial and repetitive flex borescope inspection of HPT S2 NGV P/Ns 1647M84G09 and 1647M84G10.
FAA's Determination and Requirements of This AD
Although no airplanes that are registered in the United States use these GE CF6-80E1 model turbofan engines, the possibility exists that the engine model could be used on airplanes that are registered in the United States in the future. The unsafe condition described previously is likely to exist or develop on other GE CF6-80E1 model turbofan engines of the same type design. We are issuing this AD to prevent blade failure from HPT S2 NGV distress, which could result in an uncontained engine failure. This AD requires flex borescope inspections of HPT S2 NGVs installed in GE CF6-80E1 model turbofan engines. These actions are required at initial and repetitive compliance intervals that are reduced from the intervals in AD 2002-01-04. You must use the service information described previously to perform the actions required by this AD.
FAA's Determination of the Effective Date
Since there are currently no domestic operators of this engine model, notice and opportunity for public comment before issuing this AD are unnecessary. Therefore, a situation exists that allows the immediate adoption of this regulation.
Comments Invited
This AD is a final rule that involves requirements affecting flight safety and was not preceded by notice and an opportunity for public comment; however, we invite you to submit any written relevant data, views, or arguments regarding this AD. Send your comments to an address listed under ADDRESSES. Include "AD Docket No. 2001-NE-45-AD" in the subject line of your comments. If you want us to acknowledge receipt of your mailed comments, send us a self-addressed, stamped postcard with the docket number written on it; we will date-stamp your postcard and mail it back to you. We specifically invite comments onthe overall regulatory, economic, environmental, and energy aspects of the rule that might suggest a need to modify it. If a person contacts us verbally, and that contact relates to a substantive part of this AD, we will summarize the contact and place the summary in the docket. We will consider all comments received by the closing date and may amend the AD in light of those comments.
We are reviewing the writing style we currently use in regulatory documents. We are interested in your comments on whether the style of this document is clear, and your suggestions to improve the clarity of our communications with you. You may get more information about plain language at http://www.faa.gov/language and http://www/plainlanguage.gov.
Examining the AD Docket
You may examine the AD Docket (including any comments and service information), by appointment, between 8 a.m. and 4:30 p.m., Monday through Friday, except Federal holidays. See ADDRESSES for the location.
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 the regulation:
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. 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 by sending a request to us at the address listed under ADDRESSES. Include "AD Docket No. 2001-NE-45-AD" in your request.
List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation safety, Incorporation by reference, Safety.
Adoption of the Amendment
Accordingly, under the authority delegated to me by the Administrator, the Federal Aviation Administration amends part 39 of the Federal Aviation Regulations (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.
39.13 [Amended]
2. The FAA amends 39.13 by removing Amendment 39-12595 (67 FR 4326, January 30, 2002) and by adding a new airworthiness directive, Amendment 39-13625, to read as follows: