Document ID: FAA-2015-4023-0001
Agency: faa
Document Type: Proposed Rule
Title: Airworthiness Directives: General Electric Co. Turbofan Engines
Posted Date: 2015-11-17T05:00Z

[Federal Register Volume 80, Number 221 (Tuesday, November 17, 2015)]
[Proposed Rules]
[Pages 71747-71749]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2015-28898]

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2015-4023; Directorate Identifier 2015-NE-29-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) CF6-80E1 turbofan engines with rotating 
compressor discharge pressure (CDP) seal, part number (P/N) 1669M73P02, 
installed. This proposed AD was prompted by reports from the 
manufacturer of cracks in the teeth of two rotating CDP seals found 
during engine shop visits. This proposed AD would require stripping of 
the coating, inspecting, and recoating the teeth of the affected 
rotating CDP seals. We are proposing this AD to prevent cracking of the 
CDP seal teeth, which can lead to uncontained part release, damage to 
the engine, and damage to the airplane.

DATES: We must receive comments on this proposed AD by January 19, 
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

[[Page 71748]]

285, 1 Neumann Way, Cincinnati, OH 45215; phone: 513-552-3272; email: 
aviation.fleetsupport@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-
4023; 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: Herman Mak, Aerospace Engineer, Engine 
Certification Office, FAA, Engine & Propeller Directorate, 12 New 
England Executive Park, Burlington, MA 01803; phone: 781-238-7147; fax: 
781-238-7199; email: herman.mak@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-2015-4023; 
Directorate Identifier 2015-NE-29-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 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 reports from GE of cracks in the teeth on two rotating 
CDP seals found during engine shop visits. We learned that the current 
borazon-nickel seal tooth coating oxidizes during engine operation, 
which could lead to reduced cutting action, overheating of the seal 
teeth, and premature cracking of the seal teeth. This condition, if not 
corrected, could result in cracking of the CDP seal teeth, uncontained 
part release, damage to the engine, and damage to the airplane.

Relevant Service Information Under 1 CFR Part 51

    We reviewed GE Service Bulletin (SB) No. CF6-80E1 S/B 72-0529, 
Revision 1, dated August 21, 2015. The SB describes procedures for 
stripping, inspecting, and replacing the seal tooth coating on the 
affected rotating CDP seals. This service information is reasonably 
available because the interested parties have access to it through 
their normal course of business or by the means identified in the 
ADDRESSES section of this document.

Other Related Service Information

    We reviewed GE CF6-80E1 (GEK99376) Engine Manual, Revision 42, 
dated March 15, 2014. The engine manual describes acceptable repair 
procedures for the seal teeth.

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 stripping, inspecting, and recoating 
the teeth on the affected CDP seals.

Costs of Compliance

    We estimate that this proposed AD will affect 6 engines installed 
on airplanes of U.S. registry. We also estimate that it will take about 
7 hours per engine to comply with this proposed AD. The average labor 
rate is $85 per hour. Parts would cost about $7,835 per engine. Based 
on these figures, we estimate the total cost of this proposed AD to 
U.S. operators to be $50,657.

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-2015-4023; Directorate 
Identifier 2015-NE-29-AD.

(a) Comments Due Date

    We must receive comments by January 19, 2016.

(b) Affected ADs

    None.

[[Page 71749]]

(c) Applicability

    This AD applies to all General Electric Company (GE) CF6-80E1 
turbofan engines with rotating compressor discharge pressure (CDP) 
seals, part number (P/N) 1669M73P02, installed.

(d) Unsafe Condition

    This AD was prompted by reports from the manufacturer of cracks 
in the teeth of two rotating CDP seals found during engine shop 
visits. We are issuing this AD to prevent cracking of the CDP seal 
teeth, which can lead to uncontained part release, damage to the 
engine, and damage to the airplane.

(e) Compliance

    (1) Comply with this AD within the compliance times specified, 
unless already done.
    (2) After the effective date of this AD, strip coating, inspect, 
and recoat the teeth of the rotating CDP seal, P/N 1669M73P02, in 
accordance with paragraph 3.C.(2) of GE Service Bulletin (SB) No. 
CF6-80E1 S/B 72-0529, Revision 1, dated August 21, 2015, as follows:
    (i) For engines that have had stationary CDP seal, P/N 
1347M28G02, repaired or replaced, strip coating, inspect, and recoat 
the rotating CDP seal at the next engine shop visit.
    (ii) For engines that have not had stationary CDP seal, P/N 
1347M28G02, repaired or replaced, strip coating, inspect, and recoat 
the rotating CDP seal at the next part exposure.

(f) Definitions

    (1) For the purpose of this AD, part exposure is defined as 
removal of the compressor rear frame from the high-pressure 
compressor module.
    (2) For the purpose of this AD, an engine shop visit is defined 
as the induction of an engine into the shop for maintenance 
involving the separation of pairs of major mating engine flanges, 
except that the separation of engine flanges solely for the purposes 
of transportation without subsequent engine maintenance does not 
constitute an engine shop visit.

(g) Credit for Previous Action

    If you stripped, inspected, and recoated the CDP seal, P/N 
1669M73P02, using the procedures in ESM 72-31-10, REPAIR 002 of the 
GE CF6-80E1 (GEK99376) Engine Manual, Revision 42, dated March 15, 
2014, or earlier versions, then you met the requirements of this AD.

(h) Alternative Methods of Compliance (AMOCs)

    The Manager, Engine Certification Office, FAA, may approve AMOCs 
to 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 Herman Mak, 
Aerospace Engineer, Engine Certification Office, FAA, Engine & 
Propeller Directorate, 12 New England Executive Park, Burlington, MA 
01803; phone: 781-238-7147; fax: 781-238-7199; email: 
herman.mak@faa.gov.
    (2) GE SB No. CF6-80E1 S/B 72-0529, Revision 1, dated August 21, 
2015 can be obtained from GE using the contact information in 
paragraph (i)(3) of this proposed 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; email: 
aviation.fleetsupport@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 November 4, 2015.
Carlos A. Pestana,
Acting Directorate Manager, Engine & Propeller Directorate, Aircraft 
Certification Service.
[FR Doc. 2015-28898 Filed 11-16-15; 8:45 am]
BILLING CODE 4910-13-P