81 FR 19022 - Airworthiness Directives; General Electric Company Turbofan Engines

DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration

Federal Register Volume 81, Issue 64 (April 4, 2016)

We are adopting 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 AD was prompted by reports from the manufacturer of cracks in the teeth of two rotating CDP seals found during engine shop visits. This AD requires stripping of the coating, inspecting, and recoating the teeth of the affected rotating CDP seals. We are issuing this AD to prevent cracking of the CDP seal teeth, uncontained part release, damage to the engine, and damage to the airplane.

[Federal Register Volume 81, Number 64 (Monday, April 4, 2016)]
[Rules and Regulations]
[Pages 19022-19024]
From the Federal Register Online  [www.thefederalregister.org]
[FR Doc No: 2016-07377]


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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; 
Amendment 39-18445; AD 2016-06-14]
RIN 2120-AA64


Airworthiness Directives; General Electric Company Turbofan 
Engines

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule.

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SUMMARY: We are adopting 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 AD was prompted by reports from the manufacturer of 
cracks in the teeth of two rotating CDP seals found during engine shop 
visits. This AD requires stripping of the coating, inspecting, and 
recoating the teeth of the affected rotating CDP seals. We are issuing 
this AD to prevent cracking of the CDP seal teeth, uncontained part 
release, damage to the engine, and damage to the airplane.

DATES: This AD is effective May 9, 2016.
    The Director of the Federal Register approved the incorporation by 
reference of a certain publication listed in this AD as of May 9, 2016.

ADDRESSES: For service information identified in this final rule, 
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, 1200 District Avenue, 
Burlington, MA. For information on the availability of this material at 
the FAA, call 781-238-7125. It is also available on the Internet at 
http://www.regulations.gov by searching for and locating Docket No. 
FAA-2015-4023.

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 AD, the regulatory evaluation, any comments received, and 
other information. The address for the Docket Office (phone: 800-647-
5527) is Document Management Facility, U.S. Department of 
Transportation, Docket Operations, M-30, West Building Ground Floor, 
Room W12-140, 1200 New Jersey Avenue SE., Washington, DC 20590.

FOR FURTHER INFORMATION CONTACT: Herman Mak, Aerospace Engineer, Engine 
Certification Office, FAA, Engine & Propeller Directorate, 1200 
District Avenue, Burlington, MA 01803; phone: 781-238-7147; fax: 781-
238-7199; email: [email protected].

SUPPLEMENTARY INFORMATION:

Discussion

    We issued a notice of proposed rulemaking (NPRM) to amend 14 CFR 
part 39 by adding an AD that would apply to all GE CF6-80E1 turbofan 
engines with rotating CDP seal, P/N 1669M73P02, installed. The NPRM 
published in the Federal Register on November 17, 2015 (80 FR 71747). 
The NPRM was prompted by reports of cracks in the teeth of two rotating 
CDP seals found during engine shop visits. The NPRM proposed to require 
stripping of the coating, inspecting, and recoating the teeth of the 
affected rotating CDP seals. We are issuing this AD to prevent cracking 
of the CDP seal teeth, uncontained part release, damage to the engine, 
and damage to the airplane.

Comments

    We gave the public the opportunity to participate in developing 
this AD. The following presents the comments received on the NPRM (80 
FR 71747, November 17, 2015) (``the NPRM'') and the FAA's response to 
each comment.

Request To Clarify Definition

    Qantas, Air France, KLM Royal Dutch Airlines (KLM), and GE Aviation 
requested that the shop visit definition be clarified to allow for 
randomly occurring exemptions. Including exemptions would not increase 
the time between full shop visits.
    We agree. We changed the shop visit definition to include specific 
conditions that do not qualify as shop visits.

Request To Clarify the Shop Visit Definition

    KLM and Air France requested we clarify the phrase ``separation of 
pairs of major mating engine flanges''.
    We agree. We changed the definition for engine shop visit.

Request To Change Compliance Time

    Qantas requested a more restrictive compliance time for engines 
that experience blade-out events and a less restrictive compliance time 
of next part

[[Page 19023]]

exposure for all other affected engines. Only engines that experience 
blade-out conditions require urgent compliance times.
    We disagree. The compliance times in the NPRM were derived from 
analysis that includes the risks associated with engines with and 
without blade-out events. We did not change this AD.

Request To Clarify Compliance

    Qantas requested that we clarify the specific type of stationary 
CDP seal repair and that we clarify what is considered a replaced 
stationary CDP seal.
    We agree. We modified the Compliance section to specify the repair 
as `honeycomb'. We also added a definition to define a replaced CDP 
seal.

Request To Change Applicability

    KLM requested that the applicability be expanded to include spare 
parts.
    We partially agree. We agree with the concern for accidental 
installation of borazon-nickel coated rotating CDP seals because the 
NPRM does not preclude this scenario. We disagree with expanding this 
AD to include spare parts because ADs address unsafe conditions of 
engines, not spare parts. We changed this AD by adding an installation 
prohibition paragraph to address this concern.

Request To Change Credit for Previous Action

    KLM requested the Credit for Previous Action paragraph allow for 
other approved original equipment manufacturer approved procedures for 
stripping and recoating rotating CDP seal teeth. KLM recoated two CDP 
seals using a procedure approved by GE.
    We disagree. It is unknown whether previous recoating procedures 
are equivalent to the procedures specified in the Credit for Previous 
Action paragraph of this AD. Any party may submit a request for an 
Alternative Method of Compliance using the procedures listed in this 
AD. We did not change this AD.

Additional Changes

    We clarified paragraphs (e)(2)(i) and (e)(2)(ii) of this AD.
    We updated the cost estimate. We changed the Costs of Compliance 
paragraph of this AD by increasing the number of affected engines by 
four and updating the costs accordingly.

Conclusion

    We reviewed the relevant data, considered the comments received, 
and determined that air safety and the public interest require adopting 
this AD with the changes described previously.
    We also determined that these changes will not increase the 
economic burden on any operator or increase the scope of this AD.

Related Service Information Under 1 CFR Part 51

    We reviewed GE Service Bulletin (SB) CF6-80E1 S/B 72-0529, Revision 
01, 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.

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.

Costs of Compliance

    We estimate that this AD will affect 10 engines installed on 
airplanes of U.S. registry. We also estimate that it will take about 
7.15 hours per engine to comply with this 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 AD to U.S. operators to be 
$84,428.

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 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):

2016-06-14 General Electric Company: Amendment 39-18445; Docket No. 
FAA-2015-4023; Directorate Identifier 2015-NE-29-AD.

(a) Effective Date

    This AD is effective May 9, 2016.

(b) Affected ADs

    None.

(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.

[[Page 19024]]

    (2) Strip coating, inspect, and recoat the teeth of the rotating 
CDP seal, P/N 1669M73P02. Use paragraph 3.C.(2) of GE Service 
Bulletin (SB) CF6-80E1 S/B 72-0529, Revision 01, dated August 21, 
2015 to do the strip coating, inspecting, and recoating, as follows:
    (i) For engines that have had stationary CDP seal, P/N 
1347M28G02, replaced or stationary CDP seal honeycomb repaired; 
strip coating, inspect, and recoat the teeth of the rotating CDP 
seal at the next engine shop visit.
    (ii) For engines that have not had stationary CDP seal, P/N 
1347M28G02, replaced or stationary CDP seal honeycomb repaired; 
strip coating, inspect, and recoat the teeth of the rotating CDP 
seal at the next part exposure of the rotating CDP seal.

(f) Installation Prohibition

    After the effective date of this AD, do not install any rotating 
CDP seal, P/N 1669M73P02, that has not had its seal teeth recoated 
using procedures specified in ESM 72-31-10, REPAIR 002 of GE CF6-
80E1 (GEK99376) Engine Manual, Revision 42, dated March 15, 2014, 
into any engine.

(g) Definitions

    (1) For the purpose of this AD, exposure of the rotating CDP 
seal is defined as removal of the compressor rear frame from the 
high-pressure compressor (HPC) 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 any major mating engine flanges, except 
that the separation of engine flanges solely for the following 
purposes is not considered a shop visit:
    (i) Transportation without subsequent engine maintenance.
    (ii) Removing the turbine rear frame (TRF) for repair of TRF 
cracking.
    (iii) Removing the top or bottom HPC case, or both, for HPC 
airfoil maintenance.
    (iv) Removing only the accessory gearbox and/or transfer 
gearbox.
    (v) Replacing the high-pressure turbine (HPT) stage 1 blades per 
CF6-80E1 SB 72-0504 ``Quick-Turn Workscope Procedure to Replace CF6-
80E1 Stage 1 HPT Blades''.
    (3) For the purpose of this AD, a stationary CDP seal is 
replaced if at any previous shop visit, the seal has been removed 
and a different seal is installed.

(h) Credit for Previous Action

    You may take credit for the actions that are required by 
paragraph (e) of this AD if the actions were performed before the 
effective date of this AD 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.

(i) 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: [email protected].

(j) Related Information

    (1) For more information about this AD, contact Herman Mak, 
Aerospace Engineer, Engine Certification Office, FAA, Engine & 
Propeller Directorate, 1200 District Avenue, Burlington, MA 01803; 
phone: 781-238-7147; fax: 781-238-7199; email: [email protected].

(k) 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 Service Bulletin CF6-80E1 S/B 72-
0529, Revision 01, dated August 21, 2015.
    (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, 1200 District Avenue, 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 March 16, 2016.
Ann C. Mollica,
Acting Manager, Engine & Propeller Directorate, Aircraft Certification 
Service.
[FR Doc. 2016-07377 Filed 4-1-16; 8:45 am]
 BILLING CODE 4910-13-P