Airworthiness Directives; Pratt & Whitney JT9D-7R4G2 Turbofan Engines, 24613-24615 [06-3922]

Download as PDF 24613 Proposed Rules Federal Register Vol. 71, No. 80 Wednesday, April 26, 2006 This section of the FEDERAL REGISTER contains notices to the public of the proposed issuance of rules and regulations. The purpose of these notices is to give interested persons an opportunity to participate in the rule making prior to the adoption of the final rules. FARM CREDIT ADMINISTRATION 12 CFR Parts 652 and 655 RIN 3052–AC17 Federal Agricultural Mortgage Corporation Funding and Fiscal Affairs; Federal Agricultural Mortgage Corporation Disclosure and Reporting Requirements; Risk-Based Capital Requirements Proposed rule; reopening of the comment period. hsrobinson on PROD1PC68 with PROPOSALS ACTION: SUMMARY: The Farm Credit Administration (FCA) is reopening the comment period on the proposed rule that would revise risk-based capital requirements for the Federal Agricultural Mortgage Corporation (Farmer Mac or Corporation) so that interested parties will have additional time to provide comments. DATES: Please send your comments to us on or before May 17, 2006. ADDRESSES: You may mail or deliver comments to Robert Coleman, Director, Office of Secondary Market Oversight, Farm Credit Administration, 1501 Farm Credit Drive, McLean, Virginia 22102– 5090, or send them by facsimile transmission to (703) 883–4477. You may also submit your comments by electronic mail to reg-comm@fca.gov, or through the Pending Regulations section of our Web site at https://www.fca.gov, or through the Government-wide Web site https://www.regulations.gov. You may review copies of comments we receive at our office in McLean, Virginia, or from our Web site at ‘‘https:// www.fca.gov.’’ Once you are in the Web site, select ‘‘Legal Info,’’ and then select ‘‘Public Comments.’’ We will show your comments as submitted, but for technical reasons we may omit items such as logos and special characters. Identifying information you provide, such as phone numbers and addresses, will be publicly available. However, we will attempt to remove electronic-mail addresses to help reduce Internet spam. VerDate Aug<31>2005 15:03 Apr 25, 2006 Jkt 208001 FOR FURTHER INFORMATION CONTACT: Joseph T. Connor, Associate Director for Policy and Analysis, Office of Secondary Market Oversight, Farm Credit Administration, McLean, VA 22102–5090, (703) 883–4280, TTY (703) 883–4434; or Rebecca S. Orlich, Senior Counsel, Office of General Counsel, Farm Credit Administration, McLean, VA 22102– 5090, (703) 883–4020, TTY (703) 883– 4020. On November 17, 2005, FCA published a proposed rule in the Federal Register to amend regulations in parts 652 and 655 that establish a risk-based capital stress test for the Corporation as required by section 8.32 of the Farm Credit Act of 1971, as amended (12 U.S.C. 2279bb–1). See 70 FR 69692, November 17, 2005. The 90-day comment period on the proposed rule was scheduled to expire on February 15, 2006, but was extended for 60 days to April 17, 2006, in a Federal Register notice published on February 13, 2006, in response to a request for additional time. See 71 FR 7446, February 13, 2006. The FCA has now received requests from both a commercial bank and several Farm Credit System institutions to delay action on the rule until they have had sufficient time to prepare comments. These parties indicate additional time is needed to respond to this highly technical and complex proposed rule. In response to these requests, we are reopening the comment period until May 17, 2006. The FCA supports public involvement and participation in its regulatory process and invites all interested parties to review and provide their comments on the proposed rule. The FCA does not anticipate any further extensions to the comment period. SUPPLEMENTARY INFORMATION: Dated: April 20, 2006. Roland E. Smith, Secretary, Farm Credit Administration Board. [FR Doc. E6–6294 Filed 4–25–06; 8:45 am] BILLING CODE 6705–01–P PO 00000 Frm 00001 Fmt 4702 Sfmt 4702 DEPARTMENT OF TRANSPORTATION Federal Aviation Administration 14 CFR Part 39 [Docket No. FAA–2006–23742; Directorate Identifier 2005–NE–53–AD] RIN 2120–AA64 Airworthiness Directives; Pratt & Whitney JT9D–7R4G2 Turbofan Engines Federal Aviation Administration (FAA), Department of Transportation (DOT). ACTION: Notice of proposed rulemaking (NPRM). AGENCY: SUMMARY: The FAA proposes to adopt a new airworthiness directive (AD) for Pratt & Whitney (PW) JT9D–7R4G2 turbofan engines. This proposed AD would require replacing the old configuration 2nd stage high pressure turbine (HPT) air seal assembly with a new design 2nd stage HPT air seal assembly that increases cooling air flow. This proposed AD results from a report of an uncontained failure of the 2nd stage air seal assembly, caused by the air seal assembly brace disengaging from the air seal, due to insufficient cooling air flow. We are proposing this AD to prevent uncontained failure of the 2nd stage HPT air seal assembly, leading to engine in-flight shutdown and damage to the airplane. DATES: We must receive any comments on this proposed AD by June 26, 2006. ADDRESSES: Use one of the following addresses to comment on this proposed AD. • DOT Docket Web site: Go to https://dms.dot.gov and follow the instructions for sending your comments electronically. • Government-wide rulemaking Web site: Go to https://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. E:\FR\FM\26APP1.SGM 26APP1 24614 Federal Register / Vol. 71, No. 80 / Wednesday, April 26, 2006 / Proposed Rules You can get the service information identified in this proposed AD from Pratt & Whitney, 400 Main St., East Hartford, CT 06108; telephone (860) 565–8770; fax (860) 565–4503. You may examine the comments on this proposed AD in the AD docket on the Internet at https://dms.dot.gov. FOR FURTHER INFORMATION CONTACT: Kevin Donovan, Aerospace Engineer, Engine Certification Office, FAA, Engine and Propeller Directorate, 12 New England Executive Park, Burlington, MA 01803; telephone (781) 238–7743, fax (781) 238–7199. SUPPLEMENTARY INFORMATION: Comments Invited We invite you to send us any written relevant data, views, or arguments regarding this proposal. Send your comments to an address listed under ADDRESSES. Include ‘‘Docket No. FAA– 2006–23742; Directorate Identifier 2005–NE–53–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 https:// 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 DOT 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 https:// dms.dot.gov. hsrobinson on PROD1PC68 with PROPOSALS Examining the AD Docket You may examine the docket that contains the proposal, any comments received and, any final disposition in person at the DOT Docket Office 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 Docket Management Facility receives them. VerDate Aug<31>2005 15:03 Apr 25, 2006 Jkt 208001 Discussion We have received two reports of failure of the 2nd stage HPT air seal assembly, part number (P/N) 815097, installed in JT9D–7R4G2 turbofan engines. One of those failures was uncontained. We have also received reports of damage found during HPT module disassembly, such as cracked knife-edge seals, cracked antirotation slots, and brace gaps over limits, on 2nd stage HPT air seal assemblies. The old configuration 2nd stage HPT air seal assembly has a brace that can disengage and move radially, causing excessive rubbing of the air seal’s knife edge against the static honeycomb seal. This rubbing leads to local excessive temperatures, cracks, thinning of the barrel of the 2nd stage HPT air seal assembly, and separation of material. The brace disengages from the air seal due to excessive buckling stress in the brace. The buckling stress is caused by the thermal interaction of the 2nd stage HPT air seal assembly and its constraining rotors. This thermal interaction causes higher-than-predicted temperatures leading to the brace disengaging. This condition, if not corrected, could result in uncontained failure of the 2nd stage HPT air seal assembly, leading to engine in-flight shutdown and damage to the airplane. Relevant Service Information We have reviewed and approved the technical contents of PW Alert Service Bulletin JT9D–7R4–A72–596, dated September 15, 2005. That Alert Service Bulletin describes procedures for replacing 2nd stage HPT air seal assembly, P/N 815097, with a new configuration 2nd stage HPT air seal assembly that increases cooling air flow, either by installing a new 2nd stage air seal assembly or modifying the old configuration 2nd stage HPT seal assembly. 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. We are proposing this AD, which would require at the next HPT module overhaul, replacing the 2nd stage HPT air seal assembly, P/N 815097, with a new configuration 2nd stage HPT air seal assembly that increases cooling air flow, either by installing a new 2nd stage air seal assembly or modifying the old configuration 2nd stage seal assembly. The proposed AD would require you to PO 00000 Frm 00002 Fmt 4702 Sfmt 4702 use the service information described previously to perform these actions. Costs of Compliance We estimate that this proposed AD would affect 176 PW JT9D–7R4G2 turbofan engines installed on airplanes of U.S. registry. We also estimate that it would take about 64 workhours per engine to perform the proposed actions, and that the average labor rate is $80 per workhour. Required parts would cost about $5,400 per engine. Based on these figures, we estimate the total cost of the proposed AD to U.S. operators to be $1,851,520. 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 E:\FR\FM\26APP1.SGM 26APP1 Federal Register / Vol. 71, No. 80 / Wednesday, April 26, 2006 / Proposed Rules 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 Definition (h) For the purposes of this AD, an HPT module exposure is when the 1st stage HPT rotor and 2nd stage HPT rotor are removed from the HPT case, making the 2nd stage HPT vanes and 2nd stage HPT air seal assembly accessible in the HPT case. Under the authority delegated to me by the Administrator, the Federal Aviation Administration proposes to amend 14 CFR part 39 as follows: 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. PART 39—AIRWORTHINESS DIRECTIVES Related Information (j) None. 1. The authority citation for part 39 continues to read as follows: Authority: 49 U.S.C. 106(g), 40113, 44701. § 39.13 [Amended] Issued in Burlington, Massachusetts, on April 19, 2006. Thomas A. Boudreau, Acting Manager, Engine and Propeller Directorate, Aircraft Certification Service. [FR Doc. 06–3922 Filed 4–25–06; 8:45 am] 2. The FAA amends § 39.13 by adding the following new airworthiness directive: BILLING CODE 4910–13–P Pratt & Whitney: Docket No. FAA–2006– 23742; Directorate Identifier 2005–NE– 53–AD. ENVIRONMENTAL PROTECTION AGENCY 40 CFR Part 180 Comments Due Date (a) The Federal Aviation Administration (FAA) must receive comments on this airworthiness directive (AD) action by June 26, 2006. Affected ADs (b) None. (c) This AD applies to Pratt & Whitney (PW) JT9D–7R4G2 turbofan engines. These engines are installed on, but not limited to, Boeing 747–200B, –200C, –200F, and –300 airplanes. Unsafe Condition (d) This AD results from a report of an uncontained failure of the 2nd stage air seal assembly, caused by the air seal assembly brace disengaging from the air seal, due to insufficient cooling air flow. We are issuing this AD to prevent uncontained failure of the 2nd stage high pressure turbine (HPT) air seal assembly, leading to engine in-flight shutdown and damage to the airplane. Compliance hsrobinson on PROD1PC68 with PROPOSALS Endosulfan, Fenarimol, Imazalil, Oryzalin, Sodium Acifluorfen, Trifluralin, and Ziram; Proposed Tolerance Actions Environmental Protection Agency (EPA). ACTION: Proposed rule. AGENCY: Applicability (e) You are responsible for having the actions required by this AD performed at the next HPT module exposure after the effective date of this AD, unless the actions have already been done. (f) Replace the 2nd stage HPT air seal assembly, part number 815097, with a new configuration 2nd stage HPT air seal assembly that increases cooling air flow, either by installing a new 2nd stage air seal assembly, or modifying the old configuration 2nd stage HPT seal assembly. (g) Use the Accomplishment Instructions of PW Alert Service Bulletin JT9D–7R4–A72– 596, dated September 15, 2005, to do the replacement. VerDate Aug<31>2005 [EPA–HQ–OPP–2005–0459; FRL–7771–9] 15:03 Apr 25, 2006 Jkt 208001 SUMMARY: EPA is proposing to revoke certain tolerances for the insecticide endosulfan, the fungicides fenarimol, imazalil, and ziram; and the herbicide trifluralin. Also, EPA is proposing to modify certain tolerances for the insecticide endosulfan, the fungicides fenarimol, imazalil, and ziram; and the herbicides sodium acifluorfen and trifluralin. In addition, EPA is proposing to establish new tolerances for the insecticide endosulfan, the fungicides fenarimol, imazalil, and ziram; and the herbicides oryzalin and trifluralin. The regulatory actions proposed in this document are part of the Agency’s reregistration program under the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA), and the tolerance reassessment requirements of the Federal Food, Drug, and Cosmetic Act (FFDCA) section 408(q), as amended by the Food Quality Protection Act (FQPA) of 1996. By law, EPA is required by August 2006 to reassess the tolerances that were in existence on August 2, 1996. No tolerance reassessments will be counted at the time of a final rule because tolerances in existence on PO 00000 Frm 00003 Fmt 4702 Sfmt 4702 24615 August 2, 1996, that are associated with actions proposed herein were previously counted as reassessed at the time of the completed Reregistration Eligibility Decision (RED), Report of the Food Quality Protection Act (FQPA) Tolerance Reassessment Progress and Risk Management Decision (TRED), or Federal Register action. DATES: Comments must be received on or before June 26, 2006. ADDRESSES: Submit your comments, identified by docket identification (ID) number EPA–HQ–OPP–2005–0459, by one of the following methods: • Federal eRulemaking Portal: https:// www.regulations.gov. Follow the on-line instructions for submitting comments. • Mail: Office of Pesticide Programs (OPP) Regulatory Public Docket (7502C), Environmental Protection Agency, 1200 Pennsylvania Ave., NW., Washington, DC 20460–0001. • Hand Delivery: OPP Regulatory Public Docket, Environmental Protection Agency, Rm. 119, Crystal Mall #2, 1801 S. Bell St., Arlington, VA. Deliveries are only accepted during the Docket’s normal hours of operation (8:30 a.m. to 4 p.m., Monday through Friday, excluding legal holidays). Special arrangements should be made for deliveries of boxed information. The Docket telephone number is (703) 305– 5805. • Important Note: OPP will be moving to a new location the first week of May 2006. As a result, from Friday, April 28 to Friday, May 5, 2006, the OPP Regulatory Public Docket will NOT be accepting any deliveries at the Crystal Mall #2 address and this facility will be closed to the public. Beginning on May 8, 2006, the OPP Regulatory Public Docket will reopen at 8:30 a.m. and deliveries will be accepted in Rm. S–4400, One Potomac Yard (South Building), 2777 S. Crystal Drive, Arlington, VA 22202. The mail code for the mailing address will change to (7502P), but will otherwise remain the same. The OPP Regulatory Public Docket telephone number and hours of operation will remain the same after the move. Instructions: Direct your comments to docket ID number EPA–HQ–OPP–2005– 0459. EPA’s policy is that all comments received will be included in the docket without change and may be made available on-line at https:// www.regulations.gov, including any personal information provided, unless the comment includes information claimed to be Confidential Business Information (CBI) or other information whose disclosure is restricted by statute. Do not submit information that you E:\FR\FM\26APP1.SGM 26APP1

Agencies

[Federal Register Volume 71, Number 80 (Wednesday, April 26, 2006)]
[Proposed Rules]
[Pages 24613-24615]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 06-3922]


=======================================================================
-----------------------------------------------------------------------

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2006-23742; Directorate Identifier 2005-NE-53-AD]
RIN 2120-AA64


Airworthiness Directives; Pratt & Whitney JT9D-7R4G2 Turbofan 
Engines

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

ACTION: Notice of proposed rulemaking (NPRM).

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

SUMMARY: The FAA proposes to adopt a new airworthiness directive (AD) 
for Pratt & Whitney (PW) JT9D-7R4G2 turbofan engines. This proposed AD 
would require replacing the old configuration 2nd stage high pressure 
turbine (HPT) air seal assembly with a new design 2nd stage HPT air 
seal assembly that increases cooling air flow. This proposed AD results 
from a report of an uncontained failure of the 2nd stage air seal 
assembly, caused by the air seal assembly brace disengaging from the 
air seal, due to insufficient cooling air flow. We are proposing this 
AD to prevent uncontained failure of the 2nd stage HPT air seal 
assembly, leading to engine in-flight shutdown and damage to the 
airplane.

DATES: We must receive any comments on this proposed AD by June 26, 
2006.

ADDRESSES: Use one of the following addresses to comment on this 
proposed AD.
     DOT Docket Web site: Go to https://dms.dot.gov and follow 
the instructions for sending your comments electronically.
     Government-wide rulemaking Web site: Go to https://
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.

[[Page 24614]]

    You can get the service information identified in this proposed AD 
from Pratt & Whitney, 400 Main St., East Hartford, CT 06108; telephone 
(860) 565-8770; fax (860) 565-4503.
    You may examine the comments on this proposed AD in the AD docket 
on the Internet at https://dms.dot.gov.

FOR FURTHER INFORMATION CONTACT: Kevin Donovan, Aerospace Engineer, 
Engine Certification Office, FAA, Engine and Propeller Directorate, 12 
New England Executive Park, Burlington, MA 01803; telephone (781) 238-
7743, fax (781) 238-7199.

SUPPLEMENTARY INFORMATION:

Comments Invited

    We invite you to send us any written relevant data, views, or 
arguments regarding this proposal. Send your comments to an address 
listed under ADDRESSES. Include ``Docket No. FAA-2006-23742; 
Directorate Identifier 2005-NE-53-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 https://
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 
DOT 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 https://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 DOT Docket Office 
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 Docket Management Facility receives 
them.

Discussion

    We have received two reports of failure of the 2nd stage HPT air 
seal assembly, part number (P/N) 815097, installed in JT9D-7R4G2 
turbofan engines. One of those failures was uncontained. We have also 
received reports of damage found during HPT module disassembly, such as 
cracked knife-edge seals, cracked antirotation slots, and brace gaps 
over limits, on 2nd stage HPT air seal assemblies.
    The old configuration 2nd stage HPT air seal assembly has a brace 
that can disengage and move radially, causing excessive rubbing of the 
air seal's knife edge against the static honeycomb seal. This rubbing 
leads to local excessive temperatures, cracks, thinning of the barrel 
of the 2nd stage HPT air seal assembly, and separation of material. The 
brace disengages from the air seal due to excessive buckling stress in 
the brace. The buckling stress is caused by the thermal interaction of 
the 2nd stage HPT air seal assembly and its constraining rotors. This 
thermal interaction causes higher-than-predicted temperatures leading 
to the brace disengaging. This condition, if not corrected, could 
result in uncontained failure of the 2nd stage HPT air seal assembly, 
leading to engine in-flight shutdown and damage to the airplane.

Relevant Service Information

    We have reviewed and approved the technical contents of PW Alert 
Service Bulletin JT9D-7R4-A72-596, dated September 15, 2005. That Alert 
Service Bulletin describes procedures for replacing 2nd stage HPT air 
seal assembly, P/N 815097, with a new configuration 2nd stage HPT air 
seal assembly that increases cooling air flow, either by installing a 
new 2nd stage air seal assembly or modifying the old configuration 2nd 
stage HPT seal assembly.

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. We are proposing this AD, which would require 
at the next HPT module overhaul, replacing the 2nd stage HPT air seal 
assembly, P/N 815097, with a new configuration 2nd stage HPT air seal 
assembly that increases cooling air flow, either by installing a new 
2nd stage air seal assembly or modifying the old configuration 2nd 
stage seal assembly. The proposed AD would require you to use the 
service information described previously to perform these actions.

Costs of Compliance

    We estimate that this proposed AD would affect 176 PW JT9D-7R4G2 
turbofan engines installed on airplanes of U.S. registry. We also 
estimate that it would take about 64 workhours per engine to perform 
the proposed actions, and that the average labor rate is $80 per 
workhour. Required parts would cost about $5,400 per engine. Based on 
these figures, we estimate the total cost of the proposed AD to U.S. 
operators to be $1,851,520.

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

[[Page 24615]]

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 adding the following new 
airworthiness directive:

Pratt & Whitney: Docket No. FAA-2006-23742; Directorate Identifier 
2005-NE-53-AD.

Comments Due Date

    (a) The Federal Aviation Administration (FAA) must receive 
comments on this airworthiness directive (AD) action by June 26, 
2006.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to Pratt & Whitney (PW) JT9D-7R4G2 turbofan 
engines. These engines are installed on, but not limited to, Boeing 
747-200B, -200C, -200F, and -300 airplanes.

Unsafe Condition

    (d) This AD results from a report of an uncontained failure of 
the 2nd stage air seal assembly, caused by the air seal assembly 
brace disengaging from the air seal, due to insufficient cooling air 
flow. We are issuing this AD to prevent uncontained failure of the 
2nd stage high pressure turbine (HPT) air seal assembly, leading to 
engine in-flight shutdown and damage to the airplane.

Compliance

    (e) You are responsible for having the actions required by this 
AD performed at the next HPT module exposure after the effective 
date of this AD, unless the actions have already been done.
    (f) Replace the 2nd stage HPT air seal assembly, part number 
815097, with a new configuration 2nd stage HPT air seal assembly 
that increases cooling air flow, either by installing a new 2nd 
stage air seal assembly, or modifying the old configuration 2nd 
stage HPT seal assembly.
    (g) Use the Accomplishment Instructions of PW Alert Service 
Bulletin JT9D-7R4-A72-596, dated September 15, 2005, to do the 
replacement.

Definition

    (h) For the purposes of this AD, an HPT module exposure is when 
the 1st stage HPT rotor and 2nd stage HPT rotor are removed from the 
HPT case, making the 2nd stage HPT vanes and 2nd stage HPT air seal 
assembly accessible in the HPT case.

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) None.

    Issued in Burlington, Massachusetts, on April 19, 2006.
Thomas A. Boudreau,
Acting Manager, Engine and Propeller Directorate, Aircraft 
Certification Service.
[FR Doc. 06-3922 Filed 4-25-06; 8:45 am]
BILLING CODE 4910-13-P

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