Document ID: FAA-2015-7491-0001
Agency: faa
Document Type: Proposed Rule
Title: Airworthiness Directives: General Electric Company Turbofan Engines
Posted Date: 2016-01-13T05:00Z

[Federal Register Volume 81, Number 8 (Wednesday, January 13, 2016)]
[Proposed Rules]
[Pages 1582-1584]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2015-33097]

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2015-7491; Directorate Identifier 2015-NE-39-AD]
RIN 2120-AA64

Airworthiness Directives; General Electric Company Turbofan 
Engines

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: We propose to adopt a new airworthiness directive (AD) for all 
General Electric Company (GE) GE90-76B, GE90-77B, GE90-85B, GE90-90B, 
and GE90-94B turbofan engines. This proposed AD was prompted by an 
uncontained failure of the high-pressure compressor (HPC) stage 8-10 
spool, leading to an airplane fire. This proposed AD would require eddy 
current inspections (ECIs) or ultrasonic inspections (USIs) of the HPC 
stage 8-10 spool and removing from service those parts that fail 
inspection. We are proposing this AD to prevent failure of the HPC 
stage 8-10 spool, uncontained rotor release, damage to the engine, and 
damage to the airplane.

DATES: We must receive comments on this proposed AD by March 14, 2016.

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 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 Company, GE-Aviation, Room 285, 1 Neumann Way, 
Cincinnati, OH 45215, phone: 513-552-3272; fax: 513-552-3329; email: 
geae.aoc@ge.com. 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-2015-
7491; 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

[[Page 1583]]

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: John Frost, Aerospace Engineer, Engine 
Certification Office, FAA, 12 New England Executive Park, Burlington, 
MA 01803; phone: 781-238-7756; fax: 781-238-7199; email: 
john.frost@faa.gov.

SUPPLEMENTARY INFORMATION: 

Comments Invited

    We invite you to send any written relevant data, views, or 
arguments about this NPRM. Send your comments to an address listed 
under the ADDRESSES section. Include ``Docket No. FAA-2015-7491; 
Directorate Identifier 2015-NE-39-AD'' at the beginning of your 
comments. We specifically invite comments on the overall regulatory, 
economic, environmental, and energy aspects of this NPRM. We will 
consider all comments received by the closing date and may amend this 
NPRM 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 NPRM.

Discussion

    We received a report of an HPC stage 8-10 spool uncontained failure 
resulting in an airplane fire. Ongoing investigations have determined 
that a crack initiated in the stage 8 aft web upper face of the HPC 8-
10 spool and propagated until spool rupture. The root cause of the 
crack initiation is not yet known. This condition, if not corrected, 
could result in failure of the HPC stage 8-10 spool, uncontained rotor 
release, damage to the engine, and damage to the airplane. We are 
issuing this AD to correct the unsafe condition on these products.

Related Service Information

    We reviewed the following chapters of GE GE90 Engine Manual, 
GEK100700, Revision 66, dated September 1, 2015:
     Chapter 72-31-08, Special Procedure 003, piece-part level 
ECI,
     Chapter 72-00-31, Special Procedure 006, rotor assembly 
and module level ECI and,
     Chapter 72-00-31, Special Procedure 007, rotor assembly 
level USI.

FAA's Determination

    We are proposing this NPRM 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 NPRM would require accomplishing an ECI or USI of the stage 8 
aft web upper face of the HPC stage 8-10 spool and removing from 
service those parts that fail inspection.

Interim Action

    We consider this proposed AD interim action. GE is determining the 
root cause for the unsafe condition identified in this proposed AD. 
Once a root cause is identified, we might consider additional 
rulemaking.

Costs of Compliance

    We estimate that this proposed AD affects 54 engines installed on 
airplanes of U.S. registry. We also estimate that it will take about 7 
hours per engine to comply with this AD. The average labor rate is $85 
per hour. We estimate one part will fail inspection at a cost of 
$780,000. Based on these figures, we estimate the total cost of the AD 
to U.S. operators to be $812,130.

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

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-2015-7491; Directorate 
Identifier 2015-NE-39-AD.

(a) Comments Due Date

    We must receive comments by March 14, 2016.

(b) Affected ADs

    None.

(c) Applicability

    This AD applies to General Electric Company (GE) GE90-76B, GE90-
77B, GE90-85B, GE90-90B, and GE90-94B turbofan engines with a high-
pressure compressor (HPC) 8-10 stage spool, part numbers (P/Ns) 
1694M80G04, 1844M90G01, or 1844M90G02, installed.

(d) Unsafe Condition

    This AD was prompted by an uncontained failure of the HPC stage 
8-10 spool. We are issuing this AD to prevent failure of the HPC 
stage 8-10 spool, uncontained rotor release, damage to the engine, 
and damage to the airplane.

(e) Compliance

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

[[Page 1584]]

    (1) Perform an eddy current inspection (ECI) or ultrasonic 
inspection (USI) of the stage 8 aft web upper face of the HPC stage 
8-10 spool, before exceeding 10,500 cycles since new or within 500 
cycles in service, after the effective date of this AD, whichever 
occurs later.
    (2) At each shop visit, perform an ECI or USI of the stage 8 aft 
web upper face of the HPC stage 8-10 spool.
    (3) Remove from service any HPC stage 8-10 spool that fails the 
inspection required by paragraphs (e)(1) and (e)(2) of this AD and 
replace the spool with a spool eligible for installation.

(f) Installation Prohibition

    After the effective date of this AD, an HPC stage 8-10 spool, P/
Ns 1694M80G04, 1844M90G01, and 1844M90G02, is not eligible for 
installation into any engine, unless the spool has passed an ECI or 
USI required by paragraphs (e)(1) and (e)(2) of this AD.

(g) Definition

    For the purpose of this AD, an engine shop visit is the 
induction of an engine into the shop for maintenance during which 
the compressor discharge pressure seal face is exposed.

(h) Alternative Methods of Compliance (AMOCs)

    The Manager, Engine Certification Office, FAA, may approve AMOCs 
for this AD. Use the procedures found in 14 CFR 39.19 to make your 
request. You may email your request to: ANE-AD-AMOC@faa.gov.

(i) Related Information

    (1) For more information about this AD, contact John Frost, 
Aerospace Engineer, Engine Certification Office, FAA, 12 New England 
Executive Park, Burlington, MA 01803; phone: 781-238-7756; fax: 781-
238-7199; email: john.frost@faa.gov.
    (2) GE GE90 Engine Manual, GEK100700, Revision 66, dated 
September 1, 2015, Chapter 72-31-08, Special Procedure 003, Chapter 
72-00-31, Special Procedure 006, and Chapter 72-00-31, Special 
Procedure 007, rotor assembly level USI can be obtained from General 
Electric Company, using the contact information in paragraph (i)(3) 
of this AD.
    (3) For service information identified in this proposed AD, 
contact General Electric Company, GE-Aviation, Room 285, 1 Neumann 
Way, Cincinnati, OH 45215, phone: 513-552-3272; fax: 513-552-3329; 
email: geae.aoc@ge.com.
    (4) 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.

    Issued in Burlington, Massachusetts, on December 22, 2015.
Colleen M. D'Alessandro,
Directorate Manager, Engine & Propeller Directorate, Aircraft 
Certification Service.
[FR Doc. 2015-33097 Filed 1-12-16; 8:45 am]
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