Airworthiness Directives; General Electric Company Turbofan Engines, 19628-19630 [2013-07546]

Download as PDF 19628 Federal Register / Vol. 78, No. 63 / Tuesday, April 2, 2013 / Proposed Rules The estimated national average operating hours presented in Table VI.2 shall be used to calculate FER. TABLE VI.2—ESTIMATED NATIONAL AVERAGE OPERATING HOUR VALUES FOR CALCULATING FER Operating mode Variable Heating ................................................................................................................................................. Cooling .................................................................................................................................................. Constant Circulation ............................................................................................................................. BILLING CODE 6450–01–P DEPARTMENT OF TRANSPORTATION Federal Aviation Administration 14 CFR Part 39 [Docket No. FAA–2013–0186; Directorate Identifier 2013–NE–11–AD] RIN 2120–AA64 Airworthiness Directives; General Electric Company Turbofan Engines Federal Aviation Administration (FAA), DOT. ACTION: Notice of proposed rulemaking (NPRM). AGENCY: We propose to adopt a new airworthiness directive (AD) for certain General Electric Company (GE) GE90– 76B, –85B, –90B, –94B, –110B1, and –115B turbofan engines. This proposed AD was prompted by multiple reports of failure of certain stage 1 high-pressure turbine (HPT) stator shrouds due to accelerated corrosion and oxidation. This proposed AD would require initial and repetitive on-wing borescope inspections (BSIs) for corrosion and oxidation, of the affected stage 1 HPT stator shrouds, and removal from service before further flight, if the parts fail the inspection. We are proposing tkelley on DSK3SPTVN1PROD with PROPOSALS SUMMARY: VerDate Mar<15>2010 17:24 Apr 01, 2013 Jkt 229001 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 PO 00000 Frm 00023 Fmt 4702 Sfmt 4702 830 640 400 830/HCR 640 400 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: Jason Yang, Aerospace Engineer, Engine Certification Office, FAA, 12 New England Executive Park, Burlington, MA 01803; phone: 781–238–7747; fax: 781– 238–7199; email: jason.yang@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– 2013–0186; Directorate Identifier 2013– NE–11–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:// 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. E:\FR\FM\02APP1.SGM 02APP1 EP02AP13.028</GPH> [FR Doc. 2013–07327 Filed 4–1–13; 8:45 am] this AD to prevent failure of the stage 1 HPT stator shrouds, resulting in inflight shutdown of one or more engines, loss of thrust control, and damage to the airplane. DATES: We must receive comments on this proposed AD by June 3, 2013. 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. For service information identified in this proposed AD, contact General Electric Company, One Neumann Way, MD Y–75, Cincinnati, OH; phone: 513– 552–2913; email: geae.aoc@ge.com; and Web site: www.GE.com. You may view the referenced service information at the FAA, Engine & Propeller Directorate, 12 New England Executive Park, Burlington, MA. For information on the availability of this material at the FAA, call 781–238–7125. HH CH CCH Multi-stage or modulating (hours) EP02AP13.027</GPH> Where: Single-stage (hours) Federal Register / Vol. 78, No. 63 / Tuesday, April 2, 2013 / Proposed Rules Discussion We received one report of an aborted takeoff, and multiple reports of stage 1 HPT stator shroud distress resulting in engine removals on airplanes with GE90 turbofan engines. Investigation revealed that the stage 1 HPT stator shrouds failed due to accelerated corrosion and oxidation. GE is still investigating the cause of the accelerated corrosion and oxidation. This condition, if not corrected, could result in failure of the stage 1 HPT stator shrouds, resulting in in-flight shutdown of one or more engines, loss of thrust control, and damage to the airplane. Relevant Service Information We reviewed GE Service Bulletin (SB) No. GE90 S/B 72–1076, dated November 19, 2012, and SB No. GE90–100 S/B 72– 0528, dated November 15, 2012. The SBs describe procedures for performing BSIs of the stage 1 HPT stator shrouds for accelerated corrosion and oxidation. 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 initial and repetitive on-wing BSIs of stage 1 HPT stator shrouds, part number (P/N) 1847M52P14, and P/N 1847M52P16, for corrosion and oxidation, and removal from service before further flight if the parts fail the inspection. tkelley on DSK3SPTVN1PROD with PROPOSALS Differences Between the Proposed AD and the Service Information The SBs require completing and sending to GE the Inspection Findings Report Form after each inspection. This proposed AD does not. Costs of Compliance We estimate that this proposed AD would affect about 100 GE90 engines installed on airplanes of U.S. registry. We also estimate that it would take about four hours per engine to perform one inspection. The average labor rate is $85 per hour. Based on these figures, we estimate the cost of the proposed AD on U.S. operators for one inspection to be $34,000. 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: VerDate Mar<15>2010 17:24 Apr 01, 2013 Jkt 229001 19629 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. General Electric Company: Docket No. FAA– 2013–0186; Directorate Identifier 2013– NE–11–AD. 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. (d) Unsafe Condition This AD was prompted by multiple reports of failure of certain stage 1 HPT stator shrouds due to accelerated corrosion and oxidation. We are issuing this AD to prevent failure of the stage 1 HPT stator shrouds, resulting in in-flight shutdown of one or more engines, loss of thrust control, and damage to the airplane. 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 to the extent that it justifies making a regulatory distinction, 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. § 39.13 [Amended] 2. The FAA amends § 39.13 by adding the following new airworthiness directive (AD): ■ PO 00000 Frm 00024 Fmt 4702 Sfmt 4702 (a) Comments Due Date We must receive comments by June 3, 2013. (b) Affected ADs None. (c) Applicability This AD applies to General Electric Company (GE): (1) GE90–76B, –85B, –90B, and –94B turbofan engines with stage 1 high-pressure turbine (HPT) stator shrouds, part number (P/ N) 1847M52P14, installed. (2) GE90–110B1 and –115B turbofan engines with stage 1 HPT stator shrouds, P/ N 1847M52P16, installed. (e) Compliance Comply with this AD within the compliance times specified, unless already done. (f) Borescope Inspections of the Stage 1 HPT Stator Shrouds (1) Perform an initial on-wing borescope inspection (BSI) of the stage 1 HPT stator shrouds for corrosion and oxidation before accumulating 2,100 cycles since new (CSN), or within 100 cycles in service (CIS) after the effective date of this AD, whichever occurs later. (2) Thereafter, repeat the BSI of the stage 1 HPT stator shrouds every 250 cycles since last inspection (CSLI) or fewer, depending on the results of the inspection. (3) For engines listed in paragraph (c)(1) of this AD: (i) Perform the inspections using Section 3.A of the Accomplishment Instructions of GE Service Bulletin (SB) No. GE90 S/B 72– 1076, dated November 19, 2012; and (ii) Use Section 3.B of the Accomplishment Instructions of SB No. GE90 S/B 72–1076, dated November 19, 2012, to determine the next inspection interval. (4) For engines listed in paragraph (c)(2) of this AD: (i) Perform the inspections using Section 3.A of the Accomplishment Instructions of GE SB No. GE90–100 S/B 72–0528, dated November 15, 2012; and (ii) Use Section 3.B of the Accomplishment Instructions of SB No. GE90–100 S/B 72– 0528, dated November 15, 2012, to determine the next inspection interval. (5) Remove from service before further flight, any stage 1 HPT stator shrouds found with any hole further than 0.35-inch from the shroud leading edge and hole size more than 0.25-inch diameter, or more than 0.049 square inch area. (6) The inspection findings reporting specified in Section 3.A of the E:\FR\FM\02APP1.SGM 02APP1 19630 Federal Register / Vol. 78, No. 63 / Tuesday, April 2, 2013 / Proposed Rules Accomplishment Instructions of GE SB No. GE90 S/B 72–1076, dated November 19, 2012, and in Section 3.A of the Accomplishment Instructions of GE SB No. GE90–100 S/B 72–0528, dated November 15, 2012, are not required by this AD. (g) Alternative Methods of Compliance (AMOCs) The Manager, Engine Certification Office, FAA, may approve AMOCs for this AD. Use the procedures in 14 CFR 39.19 to make your request. (h) Related Information (1) For more information about this AD, contact Jason Yang, Aerospace Engineer, Engine Certification Office, FAA, 12 New England Executive Park, Burlington, MA 01803; phone: 781–238–7747; fax: 781–238– 7199; email: jason.yang@faa.gov. (2) For service information identified in this AD, contact General Electric Company, One Neumann Way, MD Y–75, Cincinnati, OH; phone: 513–552–2913; email: geae.aoc@ge.com; and Web site: www.GE.com. You may view the referenced service information at the FAA, Engine & Propeller Directorate, 12 New England Executive Park, Burlington, MA. For information on the availability of this material at the FAA, call 781–238–7125. Issued in Burlington, Massachusetts, on March 26, 2013. Thomas A. Boudreau, Acting Manager, Engine & Propeller Directorate, Aircraft Certification Service. [FR Doc. 2013–07546 Filed 4–1–13; 8:45 am] BILLING CODE 4910–13–P DEPARTMENT OF TRANSPORTATION Federal Aviation Administration 14 CFR Part 121 [Docket No. FAA–2012–1239] Interpretation of the Rest Requirements of Nonstop International Supplemental Operations Federal Aviation Administration (FAA), DOT. ACTION: Notice of Draft Interpretation. AGENCY: This action provides interested persons with the opportunity to comment on the FAA’s draft interpretation regarding nonstop international supplemental operations scheduled for longer than 12 hours. Additionally, this draft interpretation discusses the appropriate international flight time limitations that would apply to the operation. As discussed in the draft interpretation, the FAA finds that the operation of such flights would be precluded under the flight time limitations of the ‘‘U.S. mainland rules’’ found in the supplemental flight and duty rules. However, the operation tkelley on DSK3SPTVN1PROD with PROPOSALS SUMMARY: VerDate Mar<15>2010 18:56 Apr 01, 2013 Jkt 229001 could be conducted under the ‘‘international rules’’ provisions of our regulations. Comments must be received on or before May 2, 2013. ADDRESSES: You may send comments identified by docket number FAA– 2012–1239 using any of the following methods: • Federal eRulemaking Portal: Go to https://www.regulations.gov and follow the online instructions for sending your comments electronically. • Mail: Send Comments to Docket Operations, M–30; U.S. Department of Transportation, 1200 New Jersey Avenue SE., West Building Ground Floor, Room W12–140, West Building Ground Floor, Washington, DC 20590– 0001. • Hand Delivery: Take comments to Docket Operations in Room W12–140 of the West Building Ground Floor at 1200 New Jersey Avenue SE., Washington, DC, between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. • Fax: (202) 493–2251. FOR FURTHER INFORMATION CONTACT: Dean E. Griffith, Attorney, International Law, Legislation and Regulations Division, Office of Chief Counsel, Federal Aviation Administration, 800 Independence Avenue SW., Washington, DC 20591; telephone: (202) 267–3073; email: dean.griffith@faa.gov. SUPPLEMENTARY INFORMATION: DATES: Comments Invited The FAA invites interested persons to submit written comments, data, or views concerning this interpretation. The most helpful comments reference a specific portion of the draft interpretation, explain the reason for any recommended change, and include supporting data. To ensure the docket does not contain duplicate comments, please send only one copy of written comments, or if you are filing comments electronically, please submit your comments only one time. The FAA will file in the docket all comments received, as well as a report summarizing each substantive public contact with FAA personnel concerning this proposal. Before acting on this proposal, the FAA will consider all comments received on or before the closing date for comments and any latefiled comments if it is possible to do so without incurring expense or delay. Availability of This Draft Interpretation You can get an electronic copy using the Internet by— (1) Searching the Federal eRulemaking Portal (https:// www.regulations.gov); PO 00000 Frm 00025 Fmt 4702 Sfmt 4702 (2) Visiting the FAA’s Regulations and Policies Web page at https:// www.faa.gov/regulations_policies/; or (3) Accessing the Government Printing Office’s Web page at https:// www.gpoaccess.gov/fr/. You can also get a copy by sending a request to the Federal Aviation Administration, Office of Rulemaking, ARM–1, 800 Independence Avenue SW., Washington, DC 20591, or by calling (202) 267–9680. Make sure to identify the docket number or notice number of this proposal. Background The FAA publishes draft legal interpretations when the matter in question is likely to be highly controversial or the likely answer has the potential to significantly and adversely affect long-standing practices that regulated parties have been engaged in, reasonably believing that these practices were consistent with FAA regulations. The intent is not to seek input on whether the FAA is correct— the FAA has the responsibility for interpreting its regulations. Rather, the reason for publishing the draft interpretation for comment is to see whether there may be unintended consequences for regulated parties that merit a further examination of how the agency’s regulatory provisions should be applied in conjunction with agency policy and guidance material. We are issuing this draft interpretation because it has come to our attention that supplemental air carriers might be misinterpreting and misapplying the regulations governing flight time limitations for supplemental operations to operate international flight segments longer than 12 hours by reading § 121.509 of title 14, Code of Federal Regulations in isolation, without also complying with § 121.503(a) or, in the alternative, without adequate sleeping facilities for the flight crew as required under § 121.523(b). As discussed below, such a reading fails to consider the full meaning of the FAA’s regulations. Discussion of the Proposal I. Introduction The purpose of this notice of draft interpretation is to address whether a supplemental air carrier may conduct an international nonstop flight scheduled for more than 12 hours without crew rest facilities on board the aircraft. The answer is ‘‘no.’’ For purposes of this interpretation we will use the hypothetical example of a supplemental air carrier that has scheduled four pilots to conduct a non- E:\FR\FM\02APP1.SGM 02APP1

Agencies

[Federal Register Volume 78, Number 63 (Tuesday, April 2, 2013)]
[Proposed Rules]
[Pages 19628-19630]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2013-07546]


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

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2013-0186; Directorate Identifier 2013-NE-11-AD]
RIN 2120-AA64


Airworthiness Directives; General Electric Company 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 
certain General Electric Company (GE) GE90-76B, -85B, -90B, -94B, -
110B1, and -115B turbofan engines. This proposed AD was prompted by 
multiple reports of failure of certain stage 1 high-pressure turbine 
(HPT) stator shrouds due to accelerated corrosion and oxidation. This 
proposed AD would require initial and repetitive on-wing borescope 
inspections (BSIs) for corrosion and oxidation, of the affected stage 1 
HPT stator shrouds, and removal from service before further flight, if 
the parts fail the inspection. We are proposing this AD to prevent 
failure of the stage 1 HPT stator shrouds, resulting in in-flight 
shutdown of one or more engines, loss of thrust control, and damage to 
the airplane.

DATES: We must receive comments on this proposed AD by June 3, 2013.

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.
    For service information identified in this proposed AD, contact 
General Electric Company, One Neumann Way, MD Y-75, Cincinnati, OH; 
phone: 513-552-2913; email: geae.aoc@ge.com; and Web site: www.GE.com. 
You may view the referenced service information at the FAA, Engine & 
Propeller Directorate, 12 New England Executive Park, Burlington, MA. 
For information on the availability of this material at the FAA, call 
781-238-7125.

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: Jason Yang, Aerospace Engineer, Engine 
Certification Office, FAA, 12 New England Executive Park, Burlington, 
MA 01803; phone: 781-238-7747; fax: 781-238-7199; email: 
jason.yang@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-2013-0186; 
Directorate Identifier 2013-NE-11-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://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.

[[Page 19629]]

Discussion

    We received one report of an aborted takeoff, and multiple reports 
of stage 1 HPT stator shroud distress resulting in engine removals on 
airplanes with GE90 turbofan engines. Investigation revealed that the 
stage 1 HPT stator shrouds failed due to accelerated corrosion and 
oxidation. GE is still investigating the cause of the accelerated 
corrosion and oxidation. This condition, if not corrected, could result 
in failure of the stage 1 HPT stator shrouds, resulting in in-flight 
shutdown of one or more engines, loss of thrust control, and damage to 
the airplane.

Relevant Service Information

    We reviewed GE Service Bulletin (SB) No. GE90 S/B 72-1076, dated 
November 19, 2012, and SB No. GE90-100 S/B 72-0528, dated November 15, 
2012. The SBs describe procedures for performing BSIs of the stage 1 
HPT stator shrouds for accelerated corrosion and oxidation.

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 initial and repetitive on-wing BSIs 
of stage 1 HPT stator shrouds, part number (P/N) 1847M52P14, and P/N 
1847M52P16, for corrosion and oxidation, and removal from service 
before further flight if the parts fail the inspection.

Differences Between the Proposed AD and the Service Information

    The SBs require completing and sending to GE the Inspection 
Findings Report Form after each inspection. This proposed AD does not.

Costs of Compliance

    We estimate that this proposed AD would affect about 100 GE90 
engines installed on airplanes of U.S. registry. We also estimate that 
it would take about four hours per engine to perform one inspection. 
The average labor rate is $85 per hour. Based on these figures, we 
estimate the cost of the proposed AD on U.S. operators for one 
inspection to be $34,000.

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 to the extent 
that it justifies making a regulatory distinction, 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

0
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]

0
2. The FAA amends Sec.  39.13 by adding the following new airworthiness 
directive (AD):

General Electric Company: Docket No. FAA-2013-0186; Directorate 
Identifier 2013-NE-11-AD.

(a) Comments Due Date

    We must receive comments by June 3, 2013.

(b) Affected ADs

    None.

(c) Applicability

    This AD applies to General Electric Company (GE):
    (1) GE90-76B, -85B, -90B, and -94B turbofan engines with stage 1 
high-pressure turbine (HPT) stator shrouds, part number (P/N) 
1847M52P14, installed.
    (2) GE90-110B1 and -115B turbofan engines with stage 1 HPT 
stator shrouds, P/N 1847M52P16, installed.

(d) Unsafe Condition

    This AD was prompted by multiple reports of failure of certain 
stage 1 HPT stator shrouds due to accelerated corrosion and 
oxidation. We are issuing this AD to prevent failure of the stage 1 
HPT stator shrouds, resulting in in-flight shutdown of one or more 
engines, loss of thrust control, and damage to the airplane.

(e) Compliance

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

(f) Borescope Inspections of the Stage 1 HPT Stator Shrouds

    (1) Perform an initial on-wing borescope inspection (BSI) of the 
stage 1 HPT stator shrouds for corrosion and oxidation before 
accumulating 2,100 cycles since new (CSN), or within 100 cycles in 
service (CIS) after the effective date of this AD, whichever occurs 
later.
    (2) Thereafter, repeat the BSI of the stage 1 HPT stator shrouds 
every 250 cycles since last inspection (CSLI) or fewer, depending on 
the results of the inspection.
    (3) For engines listed in paragraph (c)(1) of this AD:
    (i) Perform the inspections using Section 3.A of the 
Accomplishment Instructions of GE Service Bulletin (SB) No. GE90 S/B 
72-1076, dated November 19, 2012; and
    (ii) Use Section 3.B of the Accomplishment Instructions of SB 
No. GE90 S/B 72-1076, dated November 19, 2012, to determine the next 
inspection interval.
    (4) For engines listed in paragraph (c)(2) of this AD:
    (i) Perform the inspections using Section 3.A of the 
Accomplishment Instructions of GE SB No. GE90-100 S/B 72-0528, dated 
November 15, 2012; and
    (ii) Use Section 3.B of the Accomplishment Instructions of SB 
No. GE90-100 S/B 72-0528, dated November 15, 2012, to determine the 
next inspection interval.
    (5) Remove from service before further flight, any stage 1 HPT 
stator shrouds found with any hole further than 0.35-inch from the 
shroud leading edge and hole size more than 0.25-inch diameter, or 
more than 0.049 square inch area.
    (6) The inspection findings reporting specified in Section 3.A 
of the

[[Page 19630]]

Accomplishment Instructions of GE SB No. GE90 S/B 72-1076, dated 
November 19, 2012, and in Section 3.A of the Accomplishment 
Instructions of GE SB No. GE90-100 S/B 72-0528, dated November 15, 
2012, are not required by this AD.

(g) Alternative Methods of Compliance (AMOCs)

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

(h) Related Information

    (1) For more information about this AD, contact Jason Yang, 
Aerospace Engineer, Engine Certification Office, FAA, 12 New England 
Executive Park, Burlington, MA 01803; phone: 781-238-7747; fax: 781-
238-7199; email: jason.yang@faa.gov.
    (2) For service information identified in this AD, contact 
General Electric Company, One Neumann Way, MD Y-75, Cincinnati, OH; 
phone: 513-552-2913; email: geae.aoc@ge.com; and Web site: 
www.GE.com. You may view the referenced service information at the 
FAA, Engine & Propeller Directorate, 12 New England Executive Park, 
Burlington, MA. For information on the availability of this material 
at the FAA, call 781-238-7125.

    Issued in Burlington, Massachusetts, on March 26, 2013.
Thomas A. Boudreau,
Acting Manager, Engine & Propeller Directorate, Aircraft Certification 
Service.
[FR Doc. 2013-07546 Filed 4-1-13; 8:45 am]
BILLING CODE 4910-13-P

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