
[Federal Register Volume 76, Number 102 (Thursday, May 26, 2011)]
[Proposed Rules]
[Pages 30573-30575]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2011-13013]


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

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2011-0278; Directorate Identifier 2010-NE-10-AD]
RIN 2120-AA64


Airworthiness Directives; General Electric Company (GE) GE90-
110B1 and GE90-115B 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 the 
products listed above, with certain part number (P/N) high-pressure 
compressor (HPC) stages 2-5 spools installed. This proposed AD would 
require eddy current inspection (ECI) or spot fluorescent penetrant 
inspection (FPI) of the stages 1-2 rotating seal teeth of the HPC 
stages 2-5 spool for cracks and would prohibit installation of HPC 
stator stage 1 interstage seals that are not pregrooved to prevent 
heavy rubs. This proposed AD was prompted by an aborted takeoff and two 
shop findings of cracks in the stages 1-2 rotating seal teeth. We are 
proposing this AD to detect cracks in the HPC stages 1-2 rotating seal 
teeth due to heavy rubs, which could result in failure of the stages 1-
2 rotating seal of the HPC

[[Page 30574]]

stages 2-5 spool, uncontained engine failure, and damage to the 
airplane.

DATES: We must receive any comments on this proposed AD by July 11, 
2011.

ADDRESSES: You may send comments by any of the following methods:
     Federal eRulemaking Portal: Go to http://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, GE-Aviation, Room 285, 1 Newman Way, Cincinnati, Ohio 
45215; e-mail: geae.aoc@ge.com; phone: 513-552-3272; fax: 513-552-3329. 
You may review copies of 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 http://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, Engine & Propeller Directorate, 12 New 
England Executive Park, Burlington, MA 01803; phone: 781-238-7747; fax: 
781-238-7199; e-mail: jason.yang@faa.gov.

SUPPLEMENTARY INFORMATION:

Comments Invited

    We invite you to send us 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-2011-0278; 
Directorate Identifier 2010-NE-10-AD'' in the subject line 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 
the proposed 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 proposed AD.

Discussion

    We received a report of an engine failure caused by the liberation 
of a portion of the HPC stages 1-2 rotating seal teeth, and subsequent 
reports of HPC stages 1-2 rotating seal teeth cracks, due to heavy 
rubs, found in engines in the shop. The heavy rubs are due to 
insufficient clearance between the rotating seal teeth and the 
abradable coating on the static seal. This proposed AD would require 
ECI or spot FPI of the stages 1-2 rotating seal teeth of the HPC stages 
2-5 spool for cracks, and would prohibit installation of HPC stator 
stage 1 interstage seals that are not pregrooved in order to prevent 
heavy rubs. This condition, if not corrected, could result in failure 
of the stages 1-2 rotating seal of the HPC stages 2-5 spool, 
uncontained engine failure, and damage to the airplane.

Relevant Service Information

    We reviewed GE Service Bulletin (SB) GE90-100 S/B 72-0320, Revision 
02, dated October 1, 2010. That service information describes 
procedures for inspecting the stages 1-2 seal teeth for cracks.

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 on other products of the same type design.

Proposed AD Requirements

    This proposed AD would require accomplishing the actions specified 
in the service information described previously.

Costs of Compliance

    We estimate that this proposed AD would affect 19 GE90-110B1 and 
GE90-115B engines installed on airplanes of U.S. registry. We also 
estimate that it would take about 2 work-hours per engine to perform 
the proposed actions, and that the average labor rate is $85 per work-
hour. Required parts would cost about $9,857 per engine. Based on these 
figures, we estimate the total cost of the proposed AD to U.S. 
operators to be $190,513.

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 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);
    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:


[[Page 30575]]


    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):

General Electric Company: Docket No. FAA-2011-0278; Directorate 
Identifier 2010-NE-10-AD.

Comments Due Date

    (a) We must receive comments by July 11, 2011.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to General Electric Company (GE) GE90-110B1 
and GE90-115B turbofan engines with high-pressure compressor (HPC) 
stages 2-5 spools, part numbers (P/Ns) 351-103-106-0, 351-103-107-0, 
351-103-108-0, 351-103-109-0, 351-103-141-0, 351-103-142-0, 351-103-
143-0 and 351-103-144-0, installed.

Unsafe Condition

    (d) This AD was prompted by an aborted takeoff and two shop 
findings of cracks in the stages 1-2 rotating seal teeth. We are 
issuing this AD to detect cracks in the HPC stages 1-2 rotating seal 
teeth due to heavy rubs, which could result in failure of the stages 
1-2 rotating seal of the HPC stages 2-5 spool, uncontained engine 
failure, and damage to the airplane.

Compliance

    (e) Comply with this AD when the HPC forward case half is 
removed from the engine after the effective date of this AD, unless 
the actions have already been done.

Inspection

    (f) Perform an eddy current inspection or a fluorescent 
penetrant inspection of the stage 1-2 seal teeth using paragraphs 
3.B. or 3.C. of GE Service Bulletin (SB) GE90-100 S/B 72-0320, 
Revision 02, dated October 1, 2010.

Disposition of Spools with Cracked Seal Teeth

    (g) If you find cracks, remove the HPC stages 2-5 spool from 
service.

Previous Credit

    (h) An inspection performed before the effective date of this AD 
using SB GE90-100 S/B 72-0320 Revision 01, dated May 11, 2010, or 
earlier revision, satisfies the inspection requirement of this AD.

Installation Prohibition

    (i) After the effective date of this AD, do not install any HPC 
forward case unless it has an HPC stator stage 1 interstage seals, 
P/N 351-109-503-0.

Alternative Methods of Compliance (AMOCs)

    (j) The Manager, Engine Certification Office, has the authority 
to approve AMOCs for this AD if requested using the procedures found 
in 14 CFR 39.19.

Related Information

    (k) Contact Jason Yang, Aerospace Engineer, Engine Certification 
Office, FAA, Engine & Propeller Directorate, 12 New England 
Executive Park, Burlington, MA 01803; phone: 781-238-7747; fax: 781-
238-7199; e-mail: jason.yang@faa.gov, for more information about 
this AD.
    (l) GE Service Bulletin GE90-100 S/B 72-0320, Revision 02, dated 
October 1, 2010, pertain to the subject of this AD. Contact General 
Electric, GE-Aviation, Room 285, 1 Newman Way, Cincinnati, Ohio 
45215; e-mail: geae.aoc@ge.com; phone: 513-552-3272; fax: 513-552-
3329, for a copy of this service information.

    Issued in Burlington, Massachusetts, on May 20, 2011.
Peter A. White,
Acting Manager, Engine and Propeller Directorate, Aircraft 
Certification Service.
[FR Doc. 2011-13013 Filed 5-25-11; 8:45 am]
BILLING CODE 4910-13-P


