Airworthiness Directives; General Electric Company CT7-5, -7, and -9 Series Turboprop Engines, 16248-16250 [E6-4700]

Download as PDF 16248 Federal Register / Vol. 71, No. 62 / Friday, March 31, 2006 / Proposed Rules aft center bodies, due to high imbalance engine conditions during flight. We are issuing this AD to prevent the forward and aft center body of the LFCEN assembly from separating, leading to additional damage to the engine and airplane, possible damage to other airplanes, and to objects on the ground. AGENCY: cooling plates installed. That AD currently requires a onetime eddy current inspection (ECI) of boltholes in certain P/N stage 2 turbine aft cooling plates. This proposed AD would expand the population of affected CT7 turboprop engine models, but would reduce the number of cooling plates affected. It would also require a onetime ECI of boltholes in certain P/N stage 2 turbine aft cooling plates. This proposed AD results from the manufacturer identifying the affected stage 2 turbine aft cooling plates by serial number. We are proposing this AD to prevent separation of the stage 2 turbine aft cooling plate, resulting in uncontained engine failure and damage to the airplane. DATES: We must receive any comments on this proposed AD by May 30, 2006. ADDRESSES: Use one of the following addresses to comment on this proposed AD. • DOT Docket Web site: Go to http://dms.dot.gov and follow the instructions for sending your comments electronically. • Government-wide rulemaking Web site: Go to http://www.regulations.gov and follow the instructions for sending your comments electronically. • Mail: Docket Management Facility; U.S. Department of Transportation, 400 Seventh Street, SW., Nassif Building, Room PL–401, Washington, DC 20590– 0001. • Fax: (202) 493–2251. • Hand Delivery: Room PL–401 on the plaza level of the Nassif Building, 400 Seventh Street, SW., Washington, DC, between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. Contact General Electric Aircraft Engines CT7 Series Turboprop Engines, 1000 Western Ave, Lynn, MA 01910; telephone (781) 594–3140, fax (781) 594–4805, for the service information identified in this proposed AD. FOR FURTHER INFORMATION CONTACT: Mark Bouyer, Engine Certification Office, FAA, Engine and Propeller Directorate, 12 New England Executive Park, Burlington, MA 01803; telephone (781) 238–7755; fax (781) 238–7199. SUPPLEMENTARY INFORMATION: SUMMARY: The FAA proposes to supersede an existing airworthiness directive (AD) for General Electric Company (GE) CT7–5A2, –5A3, –7A, –7A1, –9B, –9B1, and –9B2 turboprop engines, with certain part number (P/N) and serial number stage 2 turbine aft Comments Invited We invite you to send any written relevant data, views, or arguments regarding this proposal. Send your comments to an address listed under ADDRESSES. Include ‘‘Docket No. FAA– 2005–20944; Directorate Identifier 2003–NE–64–AD’’ in the subject line of your comments. We specifically invite comments on the overall regulatory, economic, environmental, and energy Compliance (e) You are responsible for having the actions required by this AD performed the next time the forward and aft center bodies are removed from the engine after the effective date of this AD, unless the actions have already been done. (f) Rework the forward and aft center bodies to add doublers, larger nuts and bolts, and higher strength corrosion resistant nut plates. Use paragraph 3, Accomplishment Instructions, of GE Service Bulletin No. CF6– 50 S/B 78–0242, dated September 26, 2005, to identify the procedures required to do these actions. Definition (g) For the purposes of this AD, ‘‘next time the forward and aft center bodies are removed from the engine’’ includes when the center bodies are removed from the engine to take the engine off-wing. Alternative Methods of Compliance (h) 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. Issued in Burlington, Massachusetts, on March 27, 2006. Peter A. White, Acting Manager, Engine and Propeller Directorate, Aircraft Certification Service. [FR Doc. E6–4702 Filed 3–30–06; 8:45 am] BILLING CODE 4910–13–P DEPARTMENT OF TRANSPORTATION Federal Aviation Administration 14 CFR Part 39 [Docket No. FAA–2005–20944; Directorate Identifier 2003–NE–64–AD] RIN 2120–AA64 Airworthiness Directives; General Electric Company CT7–5, –7, and –9 Series Turboprop Engines hsrobinson on PROD1PC61 with PROPOSALS Federal Aviation Administration (FAA), Department of Transportation (DOT). ACTION: Notice of proposed rulemaking (NPRM). VerDate Aug<31>2005 14:53 Mar 30, 2006 Jkt 208001 PO 00000 Frm 00003 Fmt 4702 Sfmt 4702 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:// dms.dot.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 DMS web site, anyone can find and read the comments in any of our dockets, including 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) or you may visit http:// dms.dot.gov. Examining the AD Docket You may examine the docket that contains the proposal, any comments received and any final disposition in person at the DMS Docket Offices 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. Discussion On April 19, 2005, the FAA issued AD 2005–18–01, Amendment 39–14247 (70 FR 54835, September 19, 2005). That AD requires a onetime ECI of boltholes in certain P/N stage 2 turbine aft cooling plates. That AD resulted from reports of six stage 2 turbine aft cooling plate boltholes found cracked during inspection. That condition, if not corrected, could result in stage 2 turbine aft cooling plate separation, resulting in uncontained engine failure and damage to the airplane. Actions Since AD 2005–18–01 Was Issued Since that AD was issued, GE determined that it is necessary to expand the population of affected CT7 turboprop engine models to include CT7–9C/–9C3/–9D/–9D2 turboprop engines with stage 2 turbine aft cooling plate P/N 6064T07P01, 6064T07P02, 6064T07P05, or 6068T36P01 installed. GE also defined the affected population of cooling plates by serial number. This proposed AD includes these model engines. E:\FR\FM\31MRP1.SGM 31MRP1 Federal Register / Vol. 71, No. 62 / Friday, March 31, 2006 / Proposed Rules Relevant Service Information We have reviewed and approved the technical contents of GE Alert Service Bulletin CT7–TP S/B 72–A0464, Revision 4, dated December 12, 2005, that describes procedures for performing an ECI of boltholes in certain P/N stage 2 turbine aft cooling plates and replacing the cooling plate, if necessary, with one with a serial number not listed in Section 4, Appendix A, of the SB. 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. For that reason, we are proposing this AD, which would expand the population of affected CT7 turboprop engine models, but would reduce the actual cooling plate population by specifying the affected cooling plates by serial number. This proposed AD would also require a onetime ECI of boltholes in certain P/N stage 2 turbine aft cooling plates, and replacement of the cooling plates if necessary. The proposed AD would require that you do these actions using the service information described previously. hsrobinson on PROD1PC61 with PROPOSALS Costs of Compliance We estimate that this proposed AD would affect 494 engines installed on airplanes of U.S. registry. We also estimate that it would take about 1 work hour per engine to perform the proposed actions, and that the average labor rate is $80 per work hour. Based on the number of cracks found in the inspected engines, we estimate that 2.5% of the 494 engines will require replacing stage 2 turbine aft cooling plates because of rejection by the onetime ECI. Required parts would cost about $17,000 per engine. Based on these figures, we estimate the total cost of the proposed AD to U.S. operators to be $243,520. 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 VerDate Aug<31>2005 14:53 Mar 30, 2006 Jkt 208001 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 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. 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. See the ADDRESSES section for a location to examine the regulatory evaluation. List of Subjects in 14 CFR Part 39 Air transportation, Aircraft, Aviation safety, 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. § 39.13 [Amended] 2. The FAA amends § 39.13 by removing Amendment 39–14247 (70 FR 54835, September 19, 2005) and by adding a new airworthiness directive, to read as follows: General Electric Company: Docket No. FAA– 2005–20944; Directorate Identifier 2003– NE–64–AD. Comments Due Date (a) The Federal Aviation Administration (FAA) must receive comments on this airworthiness directive (AD) action by May 30, 2006. PO 00000 Frm 00004 Fmt 4702 Sfmt 4702 16249 Affected ADs (b) This AD supersedes AD 05–18–01, Amendment 39–14247. Applicability (c) This AD applies to General Electric Company (GE) CT7–5A2/–5A3/–7A/–7A1/– 9B/–9B1/–9B2/–9C/–9C3/–9D/–9D2 turboprop engines with stage 2 turbine aft cooling plates, part number (P/N) 6064T07P01, 6064T07P02, 6064T07P05, or 6068T36P01 installed. These engines are installed on, but not limited to, Construcciones Aeronauticas, SA CN–235 series and SAAB Aircraft AB SF340 series airplanes. Unsafe Condition (d) This AD results from the manufacturer identifying the affected stage 2 turbine aft cooling plates by serial number. We are issuing this AD to prevent separation of the stage 2 turbine aft cooling plate, resulting in uncontained engine failure and damage to the airplane. Compliance (e) You are responsible for having the actions required by this AD performed at the next engine or hot section module shop visit, but before accumulating an additional 6,000 cycles-in-service after the effective date of the AD, unless already done. Onetime Eddy Current Inspection (ECI) (f) Perform a onetime ECI of the stage 2 turbine aft cooling plates P/N 6064T07P01, 6064T07P02, 6064T07P05, or 6068T36P01, that are listed by serial number in Section 4, Appendix A, of GE Alert Service Bulletin No. CT7–TP S/B 72–A0464, Revision 04, dated December 12, 2005. Use 3.(1) through 3.B.(3) of GE Alert Service Bulletin (ASB) No. CT7– TP S/B 72–A0464, Revision 4, dated December 12, 2005 to perform the inspection. (g) For stage 2 turbine aft cooling plates that do not pass the Return to Service Criteria, do either of the following: (1) Replace the stage 2 turbine aft cooling plate with a new cooling plate that has a serial number that is not listed in Section 4, Appendix A, of GE Alert Service Bulletin No. CT7–TP S/B 72–A0464, Revision 04, dated December 12, 2005, or (2) Replace the stage 2 turbine aft cooling plate with a cooling plate that meets the acceptance criteria of 3.B.(1) through 3.B.(3) of GE Alert Service Bulletin (ASB) No. CT7– TP S/B 72–A0464, Revision 4, dated December 12, 2005. (h) After the effective date of this AD, do not install any stage 2 turbine aft cooling plates with serial numbers identified in Section 4, Appendix A, without inspecting the cooling plate as specified in 3.B.(1) through 3.B.(3) of GE Alert Service Bulletin No. CT7–TP S/B 72–A0464 Revision 04, December 12, 2005. Previous Credit (i) Eddy current inspections of the stage 2 turbine aft cooling plate boltholes done before the effective date of this AD that use GE ASB No. CT7–TP S/B 72–A0464, dated February 25, 2003; or Revision 1, dated March 12, 2003; or Revision 2, dated May 9, E:\FR\FM\31MRP1.SGM 31MRP1 16250 Federal Register / Vol. 71, No. 62 / Friday, March 31, 2006 / Proposed Rules 2003; or Revision 3, dated July 23, 2004, comply with the requirements specified in this AD. Definition of Engine or Hot Section Module Shop Visit (j) For the purposes of this AD, an engine or hot section module shop visit is defined as the introduction of the engine or hot section module into a shop that includes separating major case flanges. Alternative Methods of Compliance (k) 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 (l) None. Issued in Burlington, Massachusetts, on March 24, 2006. Thomas Boudreau, Acting Manager, Engine and Propeller Directorate, Aircraft Certification Service. [FR Doc. E6–4700 Filed 3–30–06; 8:45 am] BILLING CODE 4910–13–P DEPARTMENT OF TRANSPORTATION Federal Aviation Administration 14 CFR Part 71 [Docket FAA 2005–23157; Airspace Docket 05–ANM–15] RIN 2120–AA66 Proposed Amendment to Class E Airspace; Kalispell, MT Federal Aviation Administration (FAA), DOT. ACTION: Notice of proosed rulemaking (NPRM). hsrobinson on PROD1PC61 with PROPOSALS AGENCY: SUMMARY: This action proposes to revise Class E surface airspace at Kalispell, MT. This action is necessary for the safety of Instrument Flight Rules (FR) aircraft executing Instrument Landing System (ILS) approach procedures to the newly extended runway at Kalispell/ Glacier Park International Airport, Kalispell, MT. DATES: Comments must be received on or before May 15, 2006. ADDRESSES: Send comments on this proposal to the Docket Management System, U.S. Department of Transportation, Room Plaza 401, 400 Seventh Street, SW., Washington, DC 20590–0001. You must identify FAA Docket No. FAA–2005–23157 and Airspace Docket No. 05–ANM–15, at the beginning of your comments. You may also submit comments through the Internet at http://dms.dot.gov. VerDate Aug<31>2005 14:53 Mar 30, 2006 Jkt 208001 Ed Haeseker, Federal Aviation Administration, Western En Route and Oceanic Area Office, Airspace Branch, 1601 Lind Avenue, SW., Renton, WA 98055–4056; telephone (425) 227–2527. SUPPLEMENTARY INFORMATION: FOR FURTHER INFORMATION CONTACT: Comments Invited Interested parties are invited to participate in this proposed rulemaking by submitting such written data, views, or arguments, as they may desire. Comments that provide the factual basis supporting the views and suggestions presented are particularly helpful in developing reasoned regulatory decisions on the proposal. Comments are specifically invited on the overall regulatory, aeronautical, economic, environmental, and energy-related aspects of the proposal. Communications should identify both docket numbers (FAA Docket No. 2005– 23157 and Airspace Docket No. 05– ANM–15) and be submitted in triplicate to the Docket Management System (See ADDRESSES section for address and phone number). You may also submit comments through the Internet at http://dms.got.gov. Commenters wishing to FAA to acknowledge receipt of their comments on this action must submit, with those comments, a self-addressed, stamped postcard on which the following statement is made: ‘‘Comments to FAA Docket No. 2005–23157 and Airspace Docket No. 05–ANM–15.’’ The postcard will be date/time stamped and returned to the commenter. All communications received on or before the specified closing date for comments will be considered before taking action on the proposed rule. The proposal contained in this action may be changed in light of comments received. All comments submitted will be available for examination in the public docket both before and after the closing date for comments. A report summarizing each substantive public contact with FAA personnel concerned with this rulemaking will be filed in the docket. Availability of NPRM An electronic copy of this document may be downloaded through the Internet at http://dms.dot.gov. Recently published rulemaking documents can also be accessed through the FAA’s Web page at http://www.faa.gov or the Federal Register’s Web page at http:// www.gpoaccess.gov/fr/index.html. You may review the public docket containing the proposal, any comments received, and any final disposition in person in the Dockets Office (see PO 00000 Frm 00005 Fmt 4702 Sfmt 4702 ADDRESSES section for address and phone number) between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. An informal docket may also be examined during normal business hours at the office of the Regional Air Traffic Division, Federal Aviation Administration, Western En Route and Oceanic Area Office, Airspace Branch, 1601 Lind Avenue, SW., Renton, WA 98055. Persons interested in being placed on a mailing list for future NPRMs should contact the FAA’s Office of Rulemaking, (202) 267–9677, for a copy of Advisory Circular No. 11–2A, Notice of proposed Rulemaking Distribution System, which describes the application procedures. The Proposal The FAA is proposing an amendment to Title 14 Code of Federal Regulations (14 CFR) part 71 by revising the Class E surface airspace area at Kalispell, MT. The runway was recently extended at Kalispell/Glacier International Airport. Since the runway threshold was relocated, this created a requirement for additional surface airspace to accommodate aircraft arriving via the redesigned ILS approach procedure. This action is necessary for the safety of IFR aircraft executing ILS approach procedures at Kalispell/Glacier International Airport, Kalispell, MT. Class E airspace designations are published in paragraph 6000 of FAA Order 7400.9N, Airspace Designations and Reporting Points, dated September 1, 2005, and effective September 15, 2005, which is incorporated by reference in 14 CFR 71.1. The Class E airspace designation listed in this document would be published subsequently in the order. The FAA has determined that this proposed regulation only involves an established body of technical regulations for which frequent and routine amendments are necessary to keep them operationally current. Therefore, this proposed regulation: (1) Is not a ‘‘significant regulatory action’’ under Executive Order 12866: (2) is not a ‘‘significant rule’’ under Department of Transportation (DOT) Regulatory Policies and Procedures (44 FR 11034; February 26, 1979); and (3) does not warrant preparation of a regulatory evaluation as the anticipated impact is so minimal. Since this is a routine matter that will only affect air traffic procedures and air navigation, it is certified that this proposed rule, when promulgated, will not have a significant economic impact on a substantial number of small entities under the criteria of the Regulatory Flexibility Act. E:\FR\FM\31MRP1.SGM 31MRP1

Agencies

[Federal Register Volume 71, Number 62 (Friday, March 31, 2006)]
[Proposed Rules]
[Pages 16248-16250]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: E6-4700]


-----------------------------------------------------------------------

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2005-20944; Directorate Identifier 2003-NE-64-AD]
RIN 2120-AA64


Airworthiness Directives; General Electric Company CT7-5, -7, and 
-9 Series Turboprop Engines

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

ACTION: Notice of proposed rulemaking (NPRM).

-----------------------------------------------------------------------

SUMMARY: The FAA proposes to supersede an existing airworthiness 
directive (AD) for General Electric Company (GE) CT7-5A2, -5A3, -7A, -
7A1, -9B, -9B1, and -9B2 turboprop engines, with certain part number 
(P/N) and serial number stage 2 turbine aft cooling plates installed. 
That AD currently requires a onetime eddy current inspection (ECI) of 
boltholes in certain P/N stage 2 turbine aft cooling plates. This 
proposed AD would expand the population of affected CT7 turboprop 
engine models, but would reduce the number of cooling plates affected. 
It would also require a onetime ECI of boltholes in certain P/N stage 2 
turbine aft cooling plates. This proposed AD results from the 
manufacturer identifying the affected stage 2 turbine aft cooling 
plates by serial number. We are proposing this AD to prevent separation 
of the stage 2 turbine aft cooling plate, resulting in uncontained 
engine failure and damage to the airplane.

DATES: We must receive any comments on this proposed AD by May 30, 
2006.

ADDRESSES: Use one of the following addresses to comment on this 
proposed AD.
     DOT Docket Web site: Go to http://dms.dot.gov and follow 
the instructions for sending your comments electronically.
     Government-wide rulemaking Web site: Go to http://
www.regulations.gov and follow the instructions for sending your 
comments electronically.
     Mail: Docket Management Facility; U.S. Department of 
Transportation, 400 Seventh Street, SW., Nassif Building, Room PL-401, 
Washington, DC 20590-0001.
     Fax: (202) 493-2251.
     Hand Delivery: Room PL-401 on the plaza level of the 
Nassif Building, 400 Seventh Street, SW., Washington, DC, between 9 
a.m. and 5 p.m., Monday through Friday, except Federal holidays.
    Contact General Electric Aircraft Engines CT7 Series Turboprop 
Engines, 1000 Western Ave, Lynn, MA 01910; telephone (781) 594-3140, 
fax (781) 594-4805, for the service information identified in this 
proposed AD.

FOR FURTHER INFORMATION CONTACT: Mark Bouyer, Engine Certification 
Office, FAA, Engine and Propeller Directorate, 12 New England Executive 
Park, Burlington, MA 01803; telephone (781) 238-7755; fax (781) 238-
7199.

SUPPLEMENTARY INFORMATION:

Comments Invited

    We invite you to send any written relevant data, views, or 
arguments regarding this proposal. Send your comments to an address 
listed under ADDRESSES. Include ``Docket No. FAA-2005-20944; 
Directorate Identifier 2003-NE-64-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://
dms.dot.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 
DMS web site, anyone can find and read the comments in any of our 
dockets, including 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) or you 
may visit http://dms.dot.gov.

Examining the AD Docket

    You may examine the docket that contains the proposal, any comments 
received and any final disposition in person at the DMS Docket Offices 
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.

Discussion

    On April 19, 2005, the FAA issued AD 2005-18-01, Amendment 39-14247 
(70 FR 54835, September 19, 2005). That AD requires a onetime ECI of 
boltholes in certain P/N stage 2 turbine aft cooling plates. That AD 
resulted from reports of six stage 2 turbine aft cooling plate 
boltholes found cracked during inspection. That condition, if not 
corrected, could result in stage 2 turbine aft cooling plate 
separation, resulting in uncontained engine failure and damage to the 
airplane.

Actions Since AD 2005-18-01 Was Issued

    Since that AD was issued, GE determined that it is necessary to 
expand the population of affected CT7 turboprop engine models to 
include CT7-9C/-9C3/-9D/-9D2 turboprop engines with stage 2 turbine aft 
cooling plate P/N 6064T07P01, 6064T07P02, 6064T07P05, or 6068T36P01 
installed. GE also defined the affected population of cooling plates by 
serial number. This proposed AD includes these model engines.

[[Page 16249]]

Relevant Service Information

    We have reviewed and approved the technical contents of GE Alert 
Service Bulletin CT7-TP S/B 72-A0464, Revision 4, dated December 12, 
2005, that describes procedures for performing an ECI of boltholes in 
certain P/N stage 2 turbine aft cooling plates and replacing the 
cooling plate, if necessary, with one with a serial number not listed 
in Section 4, Appendix A, of the SB.

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. For that reason, we are proposing this AD, 
which would expand the population of affected CT7 turboprop engine 
models, but would reduce the actual cooling plate population by 
specifying the affected cooling plates by serial number. This proposed 
AD would also require a onetime ECI of boltholes in certain P/N stage 2 
turbine aft cooling plates, and replacement of the cooling plates if 
necessary. The proposed AD would require that you do these actions 
using the service information described previously.

Costs of Compliance

    We estimate that this proposed AD would affect 494 engines 
installed on airplanes of U.S. registry. We also estimate that it would 
take about 1 work hour per engine to perform the proposed actions, and 
that the average labor rate is $80 per work hour. Based on the number 
of cracks found in the inspected engines, we estimate that 2.5% of the 
494 engines will require replacing stage 2 turbine aft cooling plates 
because of rejection by the onetime ECI. Required parts would cost 
about $17,000 per engine. Based on these figures, we estimate the total 
cost of the proposed AD to U.S. operators to be $243,520.

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 
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. 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. See the 
ADDRESSES section for a location to examine the regulatory evaluation.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, 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 removing Amendment 39-14247 (70 FR 
54835, September 19, 2005) and by adding a new airworthiness directive, 
to read as follows:

General Electric Company: Docket No. FAA-2005-20944; Directorate 
Identifier 2003-NE-64-AD.

Comments Due Date

    (a) The Federal Aviation Administration (FAA) must receive 
comments on this airworthiness directive (AD) action by May 30, 
2006.

Affected ADs

    (b) This AD supersedes AD 05-18-01, Amendment 39-14247.

Applicability

    (c) This AD applies to General Electric Company (GE) CT7-5A2/-
5A3/-7A/-7A1/-9B/-9B1/-9B2/-9C/-9C3/-9D/-9D2 turboprop engines with 
stage 2 turbine aft cooling plates, part number (P/N) 6064T07P01, 
6064T07P02, 6064T07P05, or 6068T36P01 installed. These engines are 
installed on, but not limited to, Construcciones Aeronauticas, SA 
CN-235 series and SAAB Aircraft AB SF340 series airplanes.

Unsafe Condition

    (d) This AD results from the manufacturer identifying the 
affected stage 2 turbine aft cooling plates by serial number. We are 
issuing this AD to prevent separation of the stage 2 turbine aft 
cooling plate, resulting in uncontained engine failure and damage to 
the airplane.

Compliance

    (e) You are responsible for having the actions required by this 
AD performed at the next engine or hot section module shop visit, 
but before accumulating an additional 6,000 cycles-in-service after 
the effective date of the AD, unless already done.

Onetime Eddy Current Inspection (ECI)

    (f) Perform a onetime ECI of the stage 2 turbine aft cooling 
plates P/N 6064T07P01, 6064T07P02, 6064T07P05, or 6068T36P01, that 
are listed by serial number in Section 4, Appendix A, of GE Alert 
Service Bulletin No. CT7-TP S/B 72-A0464, Revision 04, dated 
December 12, 2005. Use 3.(1) through 3.B.(3) of GE Alert Service 
Bulletin (ASB) No. CT7-TP S/B 72-A0464, Revision 4, dated December 
12, 2005 to perform the inspection.
    (g) For stage 2 turbine aft cooling plates that do not pass the 
Return to Service Criteria, do either of the following:
    (1) Replace the stage 2 turbine aft cooling plate with a new 
cooling plate that has a serial number that is not listed in Section 
4, Appendix A, of GE Alert Service Bulletin No. CT7-TP S/B 72-A0464, 
Revision 04, dated December 12, 2005, or
    (2) Replace the stage 2 turbine aft cooling plate with a cooling 
plate that meets the acceptance criteria of 3.B.(1) through 3.B.(3) 
of GE Alert Service Bulletin (ASB) No. CT7-TP S/B 72-A0464, Revision 
4, dated December 12, 2005.
    (h) After the effective date of this AD, do not install any 
stage 2 turbine aft cooling plates with serial numbers identified in 
Section 4, Appendix A, without inspecting the cooling plate as 
specified in 3.B.(1) through 3.B.(3) of GE Alert Service Bulletin 
No. CT7-TP S/B 72-A0464 Revision 04, December 12, 2005.

Previous Credit

    (i) Eddy current inspections of the stage 2 turbine aft cooling 
plate boltholes done before the effective date of this AD that use 
GE ASB No. CT7-TP S/B 72-A0464, dated February 25, 2003; or Revision 
1, dated March 12, 2003; or Revision 2, dated May 9,

[[Page 16250]]

2003; or Revision 3, dated July 23, 2004, comply with the 
requirements specified in this AD.

Definition of Engine or Hot Section Module Shop Visit

    (j) For the purposes of this AD, an engine or hot section module 
shop visit is defined as the introduction of the engine or hot 
section module into a shop that includes separating major case 
flanges.

Alternative Methods of Compliance

    (k) 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

    (l) None.

    Issued in Burlington, Massachusetts, on March 24, 2006.
Thomas Boudreau,
Acting Manager, Engine and Propeller Directorate, Aircraft 
Certification Service.
[FR Doc. E6-4700 Filed 3-30-06; 8:45 am]
BILLING CODE 4910-13-P