Airworthiness Directives; General Electric Company Turbofan Engines

[Federal Register Volume 78, Number 241 (Monday, December 16, 2013)]
[Rules and Regulations]
[Pages 76045-76047]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2013-29055]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2013-0879; Directorate Identifier 2013-NE-30-AD; 
Amendment 39-17694; AD 2013-24-17]
RIN 2120-AA64


Airworthiness Directives; General Electric Company Turbofan 
Engines

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule; request for comments.

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SUMMARY: We are adopting a new airworthiness directive (AD) for General 
Electric Company (GE) GE90-110B1 and GE90-115B turbofan engines with 
certain high pressure compressor (HPC) rotor stage 2-5 spools 
installed. This AD requires removing these spools from service at times 
determined by a drawdown plan. This AD was prompted by reports of 
cracks in HPC rotor stage 2-5 spool aft spacer arms. We are issuing 
this AD to prevent failure of a critical life-limited rotating engine 
part, which could result in an uncontained engine failure and damage to 
the airplane.

DATES: This AD is effective December 31, 2013.
    The Director of the Federal Register approved the incorporation by 
reference of a certain publication listed in this AD as of December 31, 
2013.
    We must receive comments on this AD by January 30, 2014.

ADDRESSES: You may send comments, using the procedures found in 14 CFR

[[Page 76046]]

11.43 and 11.45, by any of the following methods:
    <bullet> Federal eRulemaking Portal: Go to http://www.regulations.gov. Follow the instructions for submitting comments.
    <bullet> Fax: 202-493-2251.
    <bullet> 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.
    <bullet> 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 20590, between 9 a.m. and 5 p.m., 
Monday through Friday, except Federal holidays.
    For service information identified in this AD, contact General 
Electric Company, GE Aviation, Room 285, 1 Neumann Way, Cincinnati, OH 
45215, phone: (513) 552-3272; email: [email protected]. You may view this 
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 http://www.regulations.gov by searching for and locating Docket No. FAA-2013-
0879; 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 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: Tomasz Rakowski, Aerospace Engineer, 
Engine Certification Office, FAA, Engine & Propeller Directorate, 12 
New England Executive Park, Burlington, MA 01803; phone: (781) 238-
7735; fax: (781) 238-7199; email: [email protected].

SUPPLEMENTARY INFORMATION:

Discussion

    We received reports from GE of cracks in the aft spacer arms of 
several HPC rotor stage 2-5 spools, which occurred before the spools 
reached their published cyclic life limit. The cracks developed under 
the seal teeth coating, so they were undetectable by maintenance 
inspections. This AD requires removal of these spools at a reduced 
cyclic life threshold, earlier than the published cyclic life limit. 
Because some engines have spools installed that already exceed the 
reduced cyclic life threshold, this AD provides a drawdown program to 
remove the spools within risk guidelines without grounding airplanes. 
This AD also prohibits spare spools that exceed the reduced cyclic life 
threshold from re-entering service. This AD is intended to prevent HPC 
rotor stage 2-5 spool cracks from growing and causing the spool to 
separate. This condition, if not corrected, could result in failure of 
a critical life-limited rotating engine part, which could result in an 
uncontained engine failure and damage to the airplane.

Relevant Service Information

    We reviewed GE Service Bulletin (SB) No. GE90-100 S/B 72-0499, 
dated August 14, 2013. The SB lists part serial numbers affected by 
this AD.

FAA's Determination

    We are issuing 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.

AD Requirements

    This AD requires removing certain HPC rotor stage 2-5 spools from 
service at times determined by a drawdown plan outlined in the 
paragraph (f) of the compliance section of this AD.

Differences Between the AD and the Service Information

    The schedule for removal of HPC rotor spools in this AD differs 
from that of GE SB GE90-100 S/B 72-0499, dated August 14, 2013. This AD 
uses cycles to determine compliance time rather than calendar dates, 
which are used in the SB, because the unsafe condition is driven by 
cycles rather than time.

FAA's Justification and Determination of the Effective Date

    An unsafe condition exists that requires the immediate adoption of 
this AD. The FAA has found that the risk to the flying public justifies 
waiving notice and comment prior to adoption of this rule because of 
the short compliance times for HPC rotor stage 2-5 spools that are at 
or over the removal thresholds. Therefore, we find that notice and 
opportunity for prior public comment are impracticable and that good 
cause exists for making this amendment effective in less than 30 days.

Comments Invited

    This AD is a final rule that involves requirements affecting flight 
safety and was not preceded by notice and an opportunity for public 
comment. However, we invite you to send any written data, views, or 
arguments about this AD. Send your comments to an address listed under 
the ADDRESSES section. Include the docket number FAA-2013-0879 and 
Directorate Identifier 2013-NE-30-AD at the beginning of your comments. 
We specifically invite comments on the overall regulatory, economic, 
environmental, and energy aspects of this AD. We will consider all 
comments received by the closing date and may amend this AD because of 
those comments.
    We will post all comments we receive, without change, to http://www.regulations.gov, including any personal information you provide. We 
will also post a report summarizing each substantive verbal contact we 
receive about this AD.

Costs of Compliance

    We estimate that this AD will affect two GE90 engines installed on 
airplanes of U.S. registry. There is no additional labor cost to comply 
with this AD. We estimate that the cost of a replacement HPC rotor 
stage 2-5 spool prorated part is $192,800. Based on these figures, we 
estimate the total cost of this AD to U.S. operators to be $385,600.

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

    This AD will not have federalism implications under Executive Order 
13132. This AD will not have a substantial direct effect on the States, 
on the relationship between the national government and the States, or 
on the distribution of power and

[[Page 76047]]

responsibilities among the various levels of government.
    For the reasons discussed above, I certify that this AD:
    (1) Is not a ``significant regulatory action'' under Executive 
Order 12866,
    (2) Is not a ``significant rule'' under DOT Regulatory Policies and 
Procedures (44 FR 11034, February 26, 1979),
    (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.

Adoption of the Amendment

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

2013-24-17 General Electric Company: Amendment 39-17694; Docket No. 
FAA-2013-0879; Directorate Identifier 2013-NE-30-AD.

(a) Effective Date

    This AD is effective December 31, 2013.

(b) Affected ADs

    None.

(c) Applicability

    This AD applies to General Electric Company (GE) GE90-110B1 and 
GE90-115B turbofan engines with high pressure compressor (HPC) rotor 
stage 2-5 spools, part numbers (P/Ns) 351-103-106-0, 351-103-107-0, 
351-103-141-0, 351-103-142-0, 351-103-144-0, 351-103-145-0, 351-103-
148-0, 351-103-149-0, and 351-103-151-0, with spool serial numbers 
listed in paragraph 4, Appendix A of GE Service Bulletin (SB) No. 
GE90-100 S/B 72-0499, dated August 14, 2013.

(d) Unsafe Condition

    This AD was prompted by reports of cracks in HPC rotor stage 2-5 
spool aft spacer arms. We are issuing this AD to prevent failure of 
a critical life-limited rotating engine part, which could result in 
an uncontained engine failure and damage to the airplane.

(e) Compliance

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

(f) Parts Removal

    Remove from service HPC rotor stage 2-5 spools with serial 
numbers listed in paragraph 4, Appendix A of GE SB No. GE90-100 S/B 
72-0499, dated August 14, 2013, as follows:
    (1) For spools with fewer than 4,500 cycles since new (CSN) on 
the effective date of this AD, before exceeding 5,000 CSN.
    (2) For spools with 4,500 CSN or more but fewer than 5,200 CSN 
on the effective date of this AD, within an additional 500 cycles in 
service (CIS) after the effective date of this AD but not to exceed 
5,500 CSN.
    (3) For spools with 5,200 CSN or more but fewer than 5,600 CSN 
on the effective date of this AD, within an additional 300 CIS after 
the effective date of this AD but not to exceed 5,800 CSN.
    (4) For spools with 5,600 CSN or more but fewer than 5,800 CSN 
on the effective date of this AD, within an additional 200 CIS after 
the effective date of this AD but not to exceed 5,850 CSN.
    (5) For spools with 5,800 CSN or more but fewer than 6,000 CSN 
on the effective date of this AD, within an additional 50 CIS after 
the effective date of this AD but not to exceed 6,000 CSN.
    (6) For spools with 6,000 CSN or more on the effective date of 
this AD, before the next flight.
    (7) For spools that are not installed on the effective date of 
this AD and are subsequently installed onto any engine after the 
effective date of this AD, before exceeding 5,000 CSN.

(g) Prohibition Statement

    After the effective date of this AD, do not install or re-
install onto any engine any HPC rotor stage 2-5 spool with a serial 
number listed in paragraph 4, Appendix A of GE SB No. GE90-100 S/B 
72-0499, dated August 14, 2013, that exceeds 5,000 CSN.

(h) Alternative Methods of Compliance (AMOCs)

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

(i) Related Information

    For more information about this AD, contact Tomasz Rakowski, 
Aerospace Engineer, Engine Certification Office, FAA, Engine & 
Propeller Directorate, 12 New England Executive Park, Burlington, MA 
01803; phone: (781) 238-7735; fax: (781) 238-7199; email: 
[email protected].

(j) Material Incorporated by Reference

    (1) The Director of the Federal Register approved the 
incorporation by reference (IBR) of the service information listed 
in this paragraph under 5 U.S.C. 552(a) and 1 CFR part 51.
    (2) You must use this service information as applicable to do 
the actions required by this AD, unless the AD specifies otherwise.
    (i) General Electric Company (GE) Service Bulletin No. GE90-100 
S/B 72-0499, dated August 14, 2013.
    (ii) Reserved.
    (3) For GE service information identified in this AD, contact 
General Electric Company, GE Aviation, Room 285, 1 Neumann Way, 
Cincinnati, OH 45215, phone: (513) 552-3272; email: [email protected].
    (4) You may view this service information at 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.
    (5) You may view this service information at the National 
Archives and Records Administration (NARA). For information on the 
availability of this material at NARA, call 202-741-6030, or go to: 
http://www.archives.gov/federal-register/cfr/ibr-locations.html.

    Issued in Burlington, Massachusetts, on November 27, 2013.
Carlos A. Pestana,
Acting Assistant Directorate Manager, Engine & Propeller Directorate, 
Aircraft Certification Service.
[FR Doc. 2013-29055 Filed 12-13-13; 8:45 am]
BILLING CODE 4910-13-P

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