AD 2008-26-02

This AD becomes effective January 26, 2009.

You can get the service information identified in this AD from General Electric Aircraft Engines CT7 Series Turboshaft Engines, 1000 Western Ave., Lynn, MA 01910; telephone (781) 594-6726; fax (781) 594-1583.

The Docket Operations office is located at Docket Management Facility, U.S. Department of Transportation, 1200 New Jersey Avenue, SE., West Building Ground Floor, Room W12-140, Washington, DC 20590-0001.

Christopher Richards, Aerospace Engineer, Engine Certification Office, FAA, Engine and Propeller Directorate, 12 New England Executive Park, Burlington, MA 01803; e-mail: christopher.j.richards@faa.gov; telephone (731) 238-7133; fax (781) 238-7199.

The FAA proposed to amend 14 CFR part 39 by superseding AD 2006-06-51, Amendment 39-14566 (71 FR 19627, April 17, 2006), with a proposed AD. The proposed AD applies to certain GE CT7-8A turboshaft engines. We published the proposed AD in the Federal Register on March 19, 2008 (73 FR 14731). That action proposed to:

• Delete the requirements to inspect the electrical chip detector, and

• Require removing any engine that has a serial number (SN) listed in Table 1 of the proposed AD within 6,200 cycles-since-new (CSN) unless the front frame was flushed and the No. 3 bearing replaced, and

• Prohibit installing any engine that has a SN listed in Table 1 of the proposed AD unless the front frame was flushed and the No. 3 bearing replaced.

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 AD, the regulatory evaluation, any comments received, and other information. The street address for the Docket Operations office (telephone (800) 647-5527) is provided in the ADDRESSES section. Comments will be available in the AD docket shortly after receipt.

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

One commenter, GE, asks that we change a typographical error in the contact information for the service information from Turboprop to Turboshaft. They also inform us they changed the contact telephone and fax numbers.

We agree. We changed Turboprop to Turboshaft, and we changed the contact telephone and fax numbers to (781) 594-6726 and (781) 594-1583 respectively.

The same commenter asks us to change the second bulleted item in Actions Since AD 2006-06-51 Was Issued section and to delete the third bulleted item.

We partially agree. Adding “within 6,200 cycles-since-new (CSN) unless * * * replaced” is more clear. However, that section appears in the preamble of the NPRM only. The final rule doesn't contain that section so we can't make the requested change to the preamble.

The same commenter asks us to remove the paragraph prohibiting reinstallation of an engine until this AD has been complied with. The commenter states there should be no restriction on reinstalling an engine already in the field that might have been temporarily removed for maintenance or used as a spare engine. The commenter states when these engines are sent to an Engine Overhaul Shop (within 6,200 CSN) they will get their front frame flushed and No. 3 bearing replaced. Therefore, within the 6,200 CSN compliance requirement, there should be no restriction to reinstalling the engines listed in Table 1 of the proposed AD.

We agree. We have deleted the installation prohibition from the regulatory text of the final rule.

The same commenter asks us to change the Relevant Service Information section and the Related Information paragraph to include Service Bulletin (SB) CT7-8 S/B 72-0017, Revision 01, dated February 15, 2008, and SB CT7-8 S/B 72-0017, Revision 02, dated May 14, 2008. The commenter states that GE issued SB CT7-8 S/B 72-0017, Revision 01, dated February 15, 2008, and SB CT7-8 S/B 72-0017, Revision 02, dated May 14, 2008, after we issued the NPRM.

We partially agree. We added SB CT7-8 S/B 72-0017, Revision 02, dated May 14, 2008, to the Related Information paragraph (i) and changed paragraph (g) to state “remove the engine from service and flush the front frame and replace the No. 3 bearing. GE Aircraft Engines Service Bulletin No. CT7-8 S/B 72-0017, Revision 02, dated May 14, 2008 or earlier revision, contains information on flushing the front frame and replacing the No. 3 bearing.” However, the Relevant Service Information section appears in the preamble of the NPRM only. The final rule doesn't contain that section so we can't make the requested change to the preamble.

The same commenter asks us to change the Related Service Information paragraph to include the compliance time of “within 6,200 CSN or at the next shop visit, whichever occurs first.” The commenter recommends inserting this information to provide a brief explanation of the intent of GE CT7-8 Service Bulletin 72-0017.

We don't agree. We already specify the compliance times in the regulatory text. The purpose of the Related Service Information paragraph is to provide a user with additional information that they can use when complying with the regulatory requirements of the AD.

The same commenter asks us to remove engine SN 947266 from Table 1 of the AD. The commenter states that they added that engine to the “completed compliance list” in Revision 01 of GE Aircraft Engines CT7-8 Service Bulletin 72-0017.

We agree. We removed engine SN 947266 from Table 1 of the AD.

The same commenter asks us to replace the phrase “remove the engine from service” in paragraph (g) with “Comply with GE Aircraft Engines CT7-8 Service Bulletin 72-0017 Rev 00 or Rev 01 or Rev 02, unless the front frame was flushed and the No. 3 bearing was replaced previously.” The commenter recommends the change to clarify the requirements by stating that each engine listed in Table 1 of the AD must comply with the requirements of GE Aircraft Engines CT7-8 Service Bulletin 72-0017 within 6,200 CSN.

We partially agree. We determined paragraph (g) is clear because it states the actions apply to engines with SNs listed in Table 1 and because paragraph (e) requires performing the actions unless the actions have already been done. However, we did change paragraph (g) from “within 6,200 cycles-since new, remove engine from service” to “within 6,200 cycles-since new, remove the engine from service and flush the front frame and replace the No. 3 bearing. GE CT7-8 Shop Manual, GEK 10517, and GE Aircraft Engines Service Bulletin No. CT7-8 S/B 72-0017, Revision 02, dated May 14, 2008, or earlier revision, contain information on flushing the front frame and replacing the No. 3 bearing.” We also added a new paragraph (h) to prohibit installing any No. 3 bearing removed as required by paragraph (g).

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.

We estimate that this AD will affect 29 engines installed on helicopters of U.S. registry. We also estimate that it will take about 66.0 work-hours per engine to perform the required actions, and that the average labor rate is $80 per work-hour. Required parts will cost about $3,476 per engine. Based on these figures, we estimate the total cost of the AD to U.S. operators to be $253,924.

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.

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.

Accordingly, under the authority delegated to me by the Administrator, the Federal Aviation Administration amends 14 CFR part 39 as follows:

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

2. The FAA amends § 39.13 by removing Amendment 39-14566 (71 FR 19627, April 17, 2006) and by adding a new airworthiness directive, Amendment 39-15768, to read as follows: