Airworthiness Directives; Pratt & Whitney Turbofan Engines, 72348-72350 [2011-30137]

Download as PDF 72348 Federal Register / Vol. 76, No. 226 / Wednesday, November 23, 2011 / Proposed Rules if so equipped. Before beginning the test, the conventional oven shall be at its normal nonoperating temperature as defined in section 1.8 and described in section 2.6. Set the conventional oven test block W1 approximately in the center of the usable baking space. If there is a selector switch for selecting the mode of operation of the oven, set it for normal baking. If an oven permits baking by either forced convection by using a fan, or without forced convection, the oven is to be tested in each of those two modes. The oven shall remain on for at least one complete thermostat ‘‘cut-off/cut-on’’ of the electrical resistance heaters or gas burners after the test block temperature has increased 234 °F (130 °C) above its initial temperature. 3.1.1.1 Self-cleaning operation of a conventional oven. Establish the test conditions set forth in section 2, ‘‘TEST CONDITIONS,’’ of this Appendix. Adjust any pilot lights of a conventional gas oven in accordance with the manufacturer’s instructions and turn off the gas flow to the conventional cooking top. The temperature of the conventional oven shall be its normal nonoperating temperature as defined in section 1.8 and described in section 2.6. Then set the conventional oven’s selfcleaning process in accordance with the manufacturer’s instructions. If the selfcleaning process is adjustable, use the average time recommended by the manufacturer for a moderately soiled oven. * * * * * 3.1.2 Conventional cooking top. Establish the test conditions set forth in section 2, ‘‘TEST CONDITIONS,’’ of this Appendix. Adjust any pilot lights of a conventional gas cooking top in accordance with the manufacturer’s instructions and turn off the gas flow to the conventional oven(s), if so equipped. The temperature of the conventional cooking top shall be its normal nonoperating temperature as defined in section 1.8 and described in section 2.6. Set the test block in the center of the surface unit under test. The small test block, W2, shall be used on electric surface units of 7 inches (178 mm) or less in diameter. The large test block, W3, shall be used on electric surface units over 7 inches (177.8 mm) in diameter and on all gas surface units. Turn on the surface unit under test and set its energy input rate to the maximum setting. When the test block reaches 144 °F (80 °C) above its initial test block temperature, immediately reduce the energy input rate to 25 ± 5 percent of the maximum energy input rate. After 15 ± 0.1 minutes at the reduced energy setting, turn off the surface unit under test. mstockstill on DSK4VPTVN1PROD with PROPOSALS * * * * * 3.1.3 Microwave oven. 3.1.3.1 Microwave oven test standby mode and off mode power. Establish the testing conditions set forth in section 2, ‘‘TEST CONDITIONS,’’ of this Appendix. For microwave ovens that drop from a higher power state to a lower power state as discussed in Section 5, Paragraph 5.1, Note 1 of IEC 62301 (Second Edition) (incorporated by reference; see § 430.3), allow sufficient time for the microwave oven to reach the lower power state before proceeding with the test measurement. Follow the test procedure as specified in VerDate Mar<15>2010 17:29 Nov 22, 2011 Jkt 226001 Section 5, Paragraph 5.3.2 of IEC 62301 (Second Edition). For units in which power varies as a function of displayed time in standby mode, set the clock time to 3:23 and use the average power approach described in Section 5, Paragraph 5.3.2(a) of IEC 62301 (First Edition), but with a single test period of 10 minutes +0/¥2 sec after an additional stabilization period until the clock time reaches 3:33. If a microwave oven is capable of operation in either standby mode or off mode, as defined in sections 1.13 and 1.9, respectively, or both, test the microwave oven in each mode in which it can operate. * * * * * 3.2.3 Microwave oven test standby mode and off mode power. Make measurements as specified in Section 5, Paragraph 5.3 of IEC 62301 (Second Edition) (incorporated by reference; see § 430.3). If the microwave oven is capable of operating in standby mode, measure the average standby mode power of the microwave oven, PSB, in watts as specified in section 3.1.3.1. If the microwave oven is capable of operating in off mode, measure the average off mode power of the microwave oven, POFF, as specified in section 3.1.3.1. * * * * * 3.3.13 Record the average standby mode power, PSB, for the microwave oven standby mode, as determined in section 3.2.3 for a microwave oven capable of operating in standby mode. Record the average off mode power, POFF, for the microwave oven off mode power test, as determined in section 3.2.3 for a microwave oven capable of operating in off mode. * * * * * [FR Doc. 2011–30234 Filed 11–22–11; 8:45 am] BILLING CODE 6450–01–P DEPARTMENT OF TRANSPORTATION Federal Aviation Administration 14 CFR Part 39 [Docket No. FAA–2011–1176; Directorate Identifier 2011–NE–35–AD] RIN 2120–AA64 Federal Aviation Administration (FAA), DOT. ACTION: Notice of proposed rulemaking (NPRM). AGENCY: We propose to adopt a new airworthiness directive (AD) for Pratt & Whitney JT9D–7R4D, –7R4D1, –7R4E, –7R4E1, –7R4G2, –7R4H1, and –7R4E4 turbofan engines. This proposed AD would establish a new lower life limit for high-pressure turbine (HPT) 1st stage air seals, part number (P/N) 735907, and would require removing them from service using a drawdown schedule. This proposed AD was prompted by the SUMMARY: Frm 00018 Fmt 4702 Examining the AD Docket You may examine the AD docket on the Internet at https:// www.regulations.gov; or in person at the Docket Management Facility between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The AD docket contains this proposed AD, the regulatory evaluation, any comments received, and other information. The street address for the Docket Office (phone: (800) 647–5527) is in the ADDRESSES section. Comments will be available in the AD docket shortly after receipt. FOR FURTHER INFORMATION CONTACT: Stephen Sheely, Aerospace Engineer, Engine & Propeller Directorate, FAA, 12 New England Executive Park, Burlington, MA 01803; phone: (781) 238–7750; fax: (781) 238–7199; email: stephen.k.sheely@faa.gov. SUPPLEMENTARY INFORMATION: Airworthiness Directives; Pratt & Whitney Turbofan Engines PO 00000 determination that a new lower life limit for the HPT 1st stage air seals, P/N 735907, is necessary. We are proposing this AD to prevent critical life-limited rotating engine part failure and damage to the airplane. DATES: We must receive comments on this proposed AD by January 23, 2012. ADDRESSES: You may send comments, using the procedures found in 14 CFR 11.43 and 11.45, by any of the following methods: • Federal eRulemaking Portal: Go to https://www.regulations.gov. Follow the instructions for submitting comments. • Fax: (202) 493–2251. • Mail: U.S. Department of Transportation, Docket Operations, M–30, West Building Ground Floor, Room W12–140, 1200 New Jersey Avenue SE., Washington, DC 20590. • Hand Delivery: Deliver to Mail address above between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. Sfmt 4702 Comments Invited We invite you to send any written relevant data, views, or arguments about this proposal. Send your comments to an address listed under the ADDRESSES section. Include ‘‘Docket No. FAA– 2011–1176; Directorate Identifier 2011– NE–35–AD’’ at the beginning of your comments. We specifically invite comments on the overall regulatory, economic, environmental, and energy aspects of this proposed AD. We will consider all comments received by the closing date and may amend this proposed AD because of those comments. We will post all comments we receive, without change, to https:// E:\FR\FM\23NOP1.SGM 23NOP1 Federal Register / Vol. 76, No. 226 / Wednesday, November 23, 2011 / Proposed Rules www.regulations.gov, including any personal information you provide. We will also post a report summarizing each substantive verbal contact we receive about this proposed AD. Discussion We received two reports of HPT 1st stage air seals, P/N 735907, found cracked by fluorescent penetrant inspection during engine overhaul. The cracks were located on the flat section of the seal, between the bolted flange and the knife edge seals. One of the air seals had accumulated 11,150 cyclessince-new (CSN), and the other air seal had accumulated 13,340 CSN. The current published life limit for these seals is 15,000 CSN. Pratt & Whitney has informed us that they are preparing to issue service information which will require reducing the published life limit from 15,000 CSN to 9,000 CSN. This condition, if not corrected, could result in critical life-limited rotating engine part failure and damage to the airplane. 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 This proposed AD would require establishing a new lower life limit for HPT 1st stage air seals, P/N 735907, from 15,000 CSN, to 9,000 CSN, and would require removing them from service using a drawdown schedule. We 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 this 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), (3) Will not affect intrastate aviation in Alaska, and (4) 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. Costs of Compliance List of Subjects in 14 CFR Part 39 We estimate that this proposed AD would affect 257 Pratt & Whitney JT9D– 7R4D, –7R4D1, –7R4E, –7R4E1, –7R4G2, –7R4H1, and –7R4E4 turbofan engines installed on airplanes of U.S. registry. We also estimate that it would take about 28.8 work-hours per engine to perform the actions required by this AD, and that the average labor rate is $85 per work-hour. Required parts will cost about $37,200 per engine. Based on these figures, we estimate the total cost of the AD to U.S. operators to be $10,189,536. Air transportation, Aircraft, Aviation safety, Incorporation by reference, Safety. FAA’s Determination We are proposing this AD because we evaluated all the relevant information and determined the unsafe condition described previously is likely to exist or develop in other products of the same type design. mstockstill on DSK4VPTVN1PROD with PROPOSALS Proposed AD Requirements 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. VerDate Mar<15>2010 17:29 Nov 22, 2011 Jkt 226001 The Proposed Amendment Accordingly, under the authority delegated to me by the Administrator, the FAA 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 adding the following new airworthiness directive (AD): Pratt & Whitney: Docket No. FAA–2011– 1176; Directorate Identifier 2011–NE– 35–AD. PO 00000 Frm 00019 Fmt 4702 Sfmt 4702 72349 (a) Comments Due Date We must receive comments by January 23, 2012. (b) Affected ADs None. (c) Applicability This AD applies to Pratt & Whitney JT9D– 7R4D, –7R4D1, –7R4E, –7R4E1, –7R4G2, –7R4H1, and –7R4E4 turbofan engines. (d) Unsafe Condition This AD was prompted by the determination that a new lower life limit of 9,000 cycles-since-new (CSN) for highpressure turbine (HPT) 1st stage air seals, part number (P/N) 735907, is necessary. We are issuing this AD to prevent critical lifelimited rotating engine part failure, and damage to the airplane. (e) Compliance Comply with this AD within the compliance times specified, unless already done. (f) Removal of HPT 1st Stage Air Seals, P/N 735907 Remove HPT 1st stage air seals, P/N 735907, from service as follows: (1) For air seals that have fewer than 6,500 CSN on the effective date of this AD, remove from service before exceeding 9,000 CSN. (2) For air seals that have 6,500 CSN or more on the effective date of this AD, do the following: (i) If the engine has a shop visit before the air seal exceeds 9,000 CSN, remove the air seal from service before exceeding 9,000 CSN. (ii) If the engine does not have a shop visit before the air seal exceeds 9,000 CSN, remove the air seal from service at the next shop visit, not to exceed 2,500 cycles from the effective date of this AD or 15,000 CSN, whichever occurs first. (3) Remove from service any HPT 1st stage air seal, P/N 735907, that is installed or reinstalled after the effective date of this AD, before the air seal exceeds the new life limit of 9,000 CSN. (g) Installation Prohibition After the effective date of this AD, do not install or reinstall into any engine any HPT 1st stage air seal, P/N 735907, that exceeds the new life limit of 9,000 CSN. (h) Engine Shop Visit Definition For the purposes of this AD, an engine shop visit is the induction of an engine into the shop after the effective date of this AD, where the separation of a major engine flange occurs, except that the following maintenance actions, or any combination, are not considered engine shop visits: (1) Introduction of an engine into a shop solely for removal of the compressor top or bottom case for airfoil maintenance or variable stator vane bushing replacement. (2) Introduction of an engine into a shop solely for removal or replacement of the stage 1 fan disk. (3) Introduction of an engine into a shop solely for replacement of the turbine rear frame. E:\FR\FM\23NOP1.SGM 23NOP1 72350 Federal Register / Vol. 76, No. 226 / Wednesday, November 23, 2011 / Proposed Rules (4) Introduction of an engine into a shop solely for replacement of the accessory gearbox or transfer gearbox, or both. (5) Introduction of an engine into a shop solely for replacement of the fan forward case. (i) Alternative Methods of Compliance (AMOCs) The Manager, Engine Certification Office, may approve AMOCs for this AD. Use the procedures found in 14 CFR 39.19 to make your request. (j) Related Information For more information about this AD, contact Stephen Sheely, Aerospace Engineer, Engine & Propeller Directorate, FAA, 12 New England Executive Park, Burlington, MA 01803; phone: (781) 238–7750; fax: (781) 238–7199; email: stephen.k.sheely@faa.gov. Issued in Burlington, Massachusetts, on November 15, 2011. Peter A. White, Manager, Engine & Propeller Directorate, Aircraft Certification Service. [FR Doc. 2011–30137 Filed 11–22–11; 8:45 am] BILLING CODE 4910–13–P DEPARTMENT OF TRANSPORTATION Federal Aviation Administration 14 CFR Part 39 [Docket No. FAA–2011–1253; Directorate Identifier 2011–NM–079–AD] RIN 2120–AA64 Airworthiness Directives; Airbus Airplanes Federal Aviation Administration (FAA), DOT. ACTION: Notice of proposed rulemaking (NPRM). AGENCY: We propose to adopt a new airworthiness directive (AD) for certain Airbus Model A319, A320, and A321 airplanes that would supersede an existing AD. This proposed AD results from mandatory continuing airworthiness information (MCAI) originated by an aviation authority of another country to identify and correct an unsafe condition on an aviation product. The MCAI describes the unsafe condition as: mstockstill on DSK4VPTVN1PROD with PROPOSALS SUMMARY: Several cases of corrosion of the Main Landing Gear (MLG) support Rib 5 fitting lug bores have been reported on A320 family aeroplanes. * * * If not detected, the cracking may lead to the complete failure of the fitting and thus could affect the structural integrity of the MLG installation. EASA AD 2007–0213 was issued to address this condition * * *. After that AD was issued, a case of Rib 5, ruptured at the 4 o’clock position, was discovered on an aeroplane on which the VerDate Mar<15>2010 17:29 Nov 22, 2011 Jkt 226001 terminating action of EASA AD 2007–0213 had already been embodied * * *. Investigation of that case revealed that corrosion damage and cracking that should have been removed by repair machining was below the level of detectability of the Non Destructive Test (NDT) technique that cleared the surfaces prior to bush installation. Comments Invited * * * * * The proposed AD would require actions that are intended to address the unsafe condition described in the MCAI. DATES: We must receive comments on this proposed AD by January 9, 2012. ADDRESSES: You may send comments by any of the following methods: • Federal eRulemaking Portal: Go to https://www.regulations.gov. Follow the instructions for submitting comments. • Fax: (202) 493–2251. • Mail: U.S. Department of Transportation, Docket Operations, M–30, West Building Ground Floor, Room W12–140, 1200 New Jersey Avenue SE., Washington, DC 20590. • Hand Delivery: U.S. Department of Transportation, Docket Operations, M–30, West Building Ground Floor, Room W12–140, 1200 New Jersey Avenue SE., Washington, DC, between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. For service information identified in this proposed AD, contact Airbus, Airworthiness Office—EAS, 1 Rond Point Maurice Bellonte, 31707 Blagnac Cedex, France; telephone +33 5 61 93 36 96; fax +33 5 61 93 44 51; email: account.airworth-eas@airbus.com; Internet https://www.airbus.com. You may review copies of the referenced service information at the FAA, Transport Airplane Directorate, 1601 Lind Avenue SW., Renton, Washington. For information on the availability of this material at the FAA, call (425) 227– 1221. Discussion Examining the AD Docket You may examine the AD docket on the Internet at https://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 proposed AD, the regulatory evaluation, any comments received, and other information. The street address for the Docket Operations office (telephone (800) 647–5527) is in the ADDRESSES section. Comments will be available in the AD docket shortly after receipt. FOR FURTHER INFORMATION CONTACT: Sanjay Ralhan, Aerospace Engineer, International Branch, ANM–116, Transport Airplane Directorate, FAA, 1601 Lind Avenue SW., Renton, PO 00000 Frm 00020 Fmt 4702 Sfmt 4702 Washington 98057–3356; phone: (425) 227–1405; fax: (425) 227–1149. SUPPLEMENTARY INFORMATION: We invite you to send any written relevant data, views, or arguments about this proposed AD. Send your comments to an address listed under the ADDRESSES section. Include ‘‘Docket No. FAA–2011–1253; Directorate Identifier 2011–NM–079–AD’’ at the beginning of your comments. We specifically invite comments on the overall regulatory, economic, environmental, and energy aspects of this proposed AD. We will consider all comments received by the closing date and may amend this proposed AD based on those comments. We will post all comments we receive, without change, to https://www. regulations.gov, including any personal information you provide. We will also post a report summarizing each substantive verbal contact we receive about this proposed AD. On March 31, 2008, we issued AD 2008–08–04, Amendment 39–15456 (73 FR 19975, April 14, 2008). That AD required actions intended to address an unsafe condition on Airbus Model A318, A319, A320, and A321 airplanes. Since we issued AD 2008–08–04, Amendment 39–15456 (73 FR 19975, April 14, 2008), we have been advised that the existing AD is inadequate to address the unsafe condition. We have determined that certain airplanes need additional detailed inspections for cracks of the MLG support 5 fitting, and repair of any cracks found. The European Aviation Safety Agency (EASA), which is the Technical Agent for the Member States of the European Community, has issued EASA Airworthiness Directive 2011–0011, dated January 21, 2011 (referred to after this as ‘‘the MCAI’’), to correct an unsafe condition for the specified products. The MCAI states: Several cases of corrosion of the Main Landing Gear (MLG) support Rib 5 fitting lug bores have been reported on A320 family aeroplanes. In some instances, corrosion pits caused the cracking of the forward lug (sometimes through its complete thickness). If not detected, the cracking may lead to the complete failure of the fitting and thus could affect the structural integrity of the MLG installation. EASA AD 2007–0213 [dated August 7, 2007, which corresponds to FAA AD 2008– 08–04, Amendment 39–15456 (73 FR 19975, April 14, 2008)] was issued to address this condition and required a repetitive inspection program of the MLG support Rib 5 fitting forward lugs and, as terminating E:\FR\FM\23NOP1.SGM 23NOP1

Agencies

[Federal Register Volume 76, Number 226 (Wednesday, November 23, 2011)]
[Proposed Rules]
[Pages 72348-72350]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2011-30137]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2011-1176; Directorate Identifier 2011-NE-35-AD]
RIN 2120-AA64


Airworthiness Directives; Pratt & Whitney Turbofan Engines

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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

SUMMARY: We propose to adopt a new airworthiness directive (AD) for 
Pratt & Whitney JT9D-7R4D, -7R4D1, -7R4E, -7R4E1, -7R4G2, -7R4H1, and -
7R4E4 turbofan engines. This proposed AD would establish a new lower 
life limit for high-pressure turbine (HPT) 1st stage air seals, part 
number (P/N) 735907, and would require removing them from service using 
a drawdown schedule. This proposed AD was prompted by the determination 
that a new lower life limit for the HPT 1st stage air seals, P/N 
735907, is necessary. We are proposing this AD to prevent critical 
life-limited rotating engine part failure and damage to the airplane.

DATES: We must receive comments on this proposed AD by January 23, 
2012.

ADDRESSES: You may send comments, using the procedures found in 14 CFR 
11.43 and 11.45, by any of the following methods:
     Federal eRulemaking Portal: Go to https://www.regulations.gov. Follow the instructions for submitting comments.
     Fax: (202) 493-2251.
     Mail: U.S. Department of Transportation, Docket 
Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New 
Jersey Avenue SE., Washington, DC 20590.
     Hand Delivery: Deliver to Mail address above between 9 
a.m. and 5 p.m., Monday through Friday, except Federal holidays.

Examining the AD Docket

    You may examine the AD docket on the Internet at https://www.regulations.gov; or in person at the Docket Management Facility 
between 9 a.m. and 5 p.m., Monday through Friday, except Federal 
holidays. The AD docket contains this proposed AD, the regulatory 
evaluation, any comments received, and other information. The street 
address for the Docket Office (phone: (800) 647-5527) is in the 
ADDRESSES section. Comments will be available in the AD docket shortly 
after receipt.

FOR FURTHER INFORMATION CONTACT: Stephen Sheely, Aerospace Engineer, 
Engine & Propeller Directorate, FAA, 12 New England Executive Park, 
Burlington, MA 01803; phone: (781) 238-7750; fax: (781) 238-7199; 
email: stephen.k.sheely@faa.gov.

SUPPLEMENTARY INFORMATION: 

Comments Invited

    We invite you to send any written relevant data, views, or 
arguments about this proposal. Send your comments to an address listed 
under the ADDRESSES section. Include ``Docket No. FAA-2011-1176; 
Directorate Identifier 2011-NE-35-AD'' at the beginning of your 
comments. We specifically invite comments on the overall regulatory, 
economic, environmental, and energy aspects of this proposed AD. We 
will consider all comments received by the closing date and may amend 
this proposed AD because of those comments.
    We will post all comments we receive, without change, to https://

[[Page 72349]]

www.regulations.gov, including any personal information you provide. We 
will also post a report summarizing each substantive verbal contact we 
receive about this proposed AD.

Discussion

    We received two reports of HPT 1st stage air seals, P/N 735907, 
found cracked by fluorescent penetrant inspection during engine 
overhaul. The cracks were located on the flat section of the seal, 
between the bolted flange and the knife edge seals. One of the air 
seals had accumulated 11,150 cycles-since-new (CSN), and the other air 
seal had accumulated 13,340 CSN. The current published life limit for 
these seals is 15,000 CSN. Pratt & Whitney has informed us that they 
are preparing to issue service information which will require reducing 
the published life limit from 15,000 CSN to 9,000 CSN. This condition, 
if not corrected, could result in critical life-limited rotating engine 
part failure and damage to the airplane.

FAA's Determination

    We are proposing this AD because we evaluated all the relevant 
information and determined the unsafe condition described previously is 
likely to exist or develop in other products of the same type design.

Proposed AD Requirements

    This proposed AD would require establishing a new lower life limit 
for HPT 1st stage air seals, P/N 735907, from 15,000 CSN, to 9,000 CSN, 
and would require removing them from service using a drawdown schedule.

Costs of Compliance

    We estimate that this proposed AD would affect 257 Pratt & Whitney 
JT9D-7R4D, -7R4D1, -7R4E, -7R4E1, -7R4G2, -7R4H1, and -7R4E4 turbofan 
engines installed on airplanes of U.S. registry. We also estimate that 
it would take about 28.8 work-hours per engine to perform the actions 
required by this AD, and that the average labor rate is $85 per work-
hour. Required parts will cost about $37,200 per engine. Based on these 
figures, we estimate the total cost of the AD to U.S. operators to be 
$10,189,536.

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 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 this 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),
    (3) Will not affect intrastate aviation in Alaska, and
    (4) 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.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Incorporation by 
reference, Safety.

The Proposed Amendment

    Accordingly, under the authority delegated to me by the 
Administrator, the FAA 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 (AD):

Pratt & Whitney: Docket No. FAA-2011-1176; Directorate Identifier 
2011-NE-35-AD.

(a) Comments Due Date

    We must receive comments by January 23, 2012.

(b) Affected ADs

    None.

(c) Applicability

    This AD applies to Pratt & Whitney JT9D-7R4D, -7R4D1, -7R4E, -
7R4E1, -7R4G2, -7R4H1, and -7R4E4 turbofan engines.

(d) Unsafe Condition

    This AD was prompted by the determination that a new lower life 
limit of 9,000 cycles-since-new (CSN) for high-pressure turbine 
(HPT) 1st stage air seals, part number (P/N) 735907, is necessary. 
We are issuing this AD to prevent critical life-limited rotating 
engine part failure, and damage to the airplane.

(e) Compliance

    Comply with this AD within the compliance times specified, 
unless already done.

(f) Removal of HPT 1st Stage Air Seals, P/N 735907

    Remove HPT 1st stage air seals, P/N 735907, from service as 
follows:
    (1) For air seals that have fewer than 6,500 CSN on the 
effective date of this AD, remove from service before exceeding 
9,000 CSN.
    (2) For air seals that have 6,500 CSN or more on the effective 
date of this AD, do the following:
    (i) If the engine has a shop visit before the air seal exceeds 
9,000 CSN, remove the air seal from service before exceeding 9,000 
CSN.
    (ii) If the engine does not have a shop visit before the air 
seal exceeds 9,000 CSN, remove the air seal from service at the next 
shop visit, not to exceed 2,500 cycles from the effective date of 
this AD or 15,000 CSN, whichever occurs first.
    (3) Remove from service any HPT 1st stage air seal, P/N 735907, 
that is installed or re-installed after the effective date of this 
AD, before the air seal exceeds the new life limit of 9,000 CSN.

(g) Installation Prohibition

    After the effective date of this AD, do not install or reinstall 
into any engine any HPT 1st stage air seal, P/N 735907, that exceeds 
the new life limit of 9,000 CSN.

(h) Engine Shop Visit Definition

    For the purposes of this AD, an engine shop visit is the 
induction of an engine into the shop after the effective date of 
this AD, where the separation of a major engine flange occurs, 
except that the following maintenance actions, or any combination, 
are not considered engine shop visits:
    (1) Introduction of an engine into a shop solely for removal of 
the compressor top or bottom case for airfoil maintenance or 
variable stator vane bushing replacement.
    (2) Introduction of an engine into a shop solely for removal or 
replacement of the stage 1 fan disk.
    (3) Introduction of an engine into a shop solely for replacement 
of the turbine rear frame.

[[Page 72350]]

    (4) Introduction of an engine into a shop solely for replacement 
of the accessory gearbox or transfer gearbox, or both.
    (5) Introduction of an engine into a shop solely for replacement 
of the fan forward case.

(i) Alternative Methods of Compliance (AMOCs)

    The Manager, Engine Certification Office, may approve AMOCs for 
this AD. Use the procedures found in 14 CFR 39.19 to make your 
request.

(j) Related Information

    For more information about this AD, contact Stephen Sheely, 
Aerospace Engineer, Engine & Propeller Directorate, FAA, 12 New 
England Executive Park, Burlington, MA 01803; phone: (781) 238-7750; 
fax: (781) 238-7199; email: stephen.k.sheely@faa.gov.

    Issued in Burlington, Massachusetts, on November 15, 2011.
Peter A. White,
Manager, Engine & Propeller Directorate, Aircraft Certification 
Service.
[FR Doc. 2011-30137 Filed 11-22-11; 8:45 am]
BILLING CODE 4910-13-P

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