[Federal Register Volume 83, Number 247 (Thursday, December 27, 2018)]
[Rules and Regulations]
[Pages 66609-66612]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2018-27926]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2018-0938; Product Identifier 2018-NE-36-AD; Amendment 
39-19480; AD 2018-22-07]
RIN 2120-AA64


Airworthiness Directives; Engine Alliance 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 all 
Engine Alliance (EA) GP7270, GP7272, and GP7277 model turbofan engines. 
This AD requires inspection of the stage 6 seal ring for correct 
installation and inspection of the high-pressure compressor (HPC) 
stages 2-5 spool for cracks. This AD also requires replacement of the 
HPC stages 2-5 spool if the stage 6 seal ring is incorrectly installed 
or if the HPC stages 2-5 spool is found cracked. This AD was prompted 
by a shop finding of axial cracks in the interstage 5-6 seal teeth of 
the HPC stages 2-5 spool spacer arm, due to an incorrectly installed 
stage 6 seal ring. We are issuing this AD to address the unsafe 
condition on these products.

DATES: This AD is effective January 11, 2019.
    The Director of the Federal Register approved the incorporation by 
reference of a certain publication listed in this AD as of January 11, 
2019.
    We must receive comments on this AD by February 11, 2019.

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: 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 final rule, contact 
Engine Alliance, 411 Silver Lane, East Hartford, CT 06118; phone: 800-
565-0140; email: [email protected]; website: 
www.engineallianceportal.com. You may view this service information at 
the FAA, Engine and Propeller Standards Branch, 1200 District Avenue, 
Burlington, MA 01803. For information on the availability of this 
material at the FAA, call 781-238-7759. It is also available on the 
internet at http://www.regulations.gov by searching for and locating 
Docket No. FAA-2018-0938.

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-2018-
0938; or in person at Docket Operations between 9 a.m. and 5 p.m., 
Monday through Friday, except Federal holidays. The AD docket contains 
this final rule, the regulatory evaluation, any comments received, and 
other information. The street address for the Docket Operations (phone: 
800-647-5527) is listed above. Comments will be available in the AD 
docket shortly after receipt.

FOR FURTHER INFORMATION CONTACT: Matthew Smith, Aerospace Engineer, ECO 
Branch, FAA, 1200 District Avenue, Burlington, MA 01803; phone: 781-
238-7735; fax: 781-238-7199; email: [email protected].

SUPPLEMENTARY INFORMATION:

Discussion

    We were informed about the discovery of axial cracks in the 
interstage 5-6 seal teeth of the HPC stages 2-5 spool spacer arm, due 
to an incorrectly installed stage 6 seal ring, in a GP7270 model 
turbofan engine. The incorrect installation of the stage 6 seal ring 
created a leakage path from the aft cavity to the forward cavity of the 
HPC stage 6 disk. This leakage elevated the

[[Page 66610]]

temperature in the cavity and adversely affected the material 
properties of the HPC stages 2-5 spool. This condition, if not 
addressed, could result in failure of the HPC stages 2-5 spool, an 
uncontained HPC stages 2-5 spool release, damage to the engine, and 
damage to the airplane. We are issuing this AD to address the unsafe 
condition on these products.

Related Service Information Under 1 CFR Part 51

    We reviewed EA Alert Service Bulletin (ASB) EAGP7-A72-395, Revision 
No. 2, dated August 2, 2018. The SB describes procedures for performing 
a borescope inspection of the installed HPC stages 2-5 spool for 
cracks, visual inspection of the stage 6 seal ring for correct 
installation, visual inspection of the interstage 5-6 seal teeth for 
damage, and removal and replacement of parts if damage or defects are 
found that are outside serviceable limits, within the identified 
cycles. 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.

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 inspection of the stage 6 seal ring for correct 
installation and inspection of the HPC stages 2-5 spool for cracks. 
This AD also requires removal and replacement of the HPC stages 2-5 
spool if the stage 6 seal ring is incorrectly installed or the 
interstage 5-6 seal teeth are found cracked.

FAA's Justification and Determination of the Effective Date

    No domestic operators use this product. Therefore, we find good 
cause that notice and opportunity for prior public comment are 
unnecessary. In addition, for the reason stated above, we find 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 final rule. Send your comments to an address 
listed under the ADDRESSES section. Include the docket number FAA-2018-
0938 and Product Identifier 2018-NE-36-AD at the beginning of your 
comments. We specifically invite comments on the overall regulatory, 
economic, environmental, and energy aspects of this final rule. We will 
consider all comments received by the closing date and may amend this 
final rule 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 final rule.

Costs of Compliance

    We estimate that this AD affects zero engines installed on 
airplanes of U.S. registry.
    We estimate the following costs to comply with this AD:

                                                 Estimated Costs
----------------------------------------------------------------------------------------------------------------
                                                                                     Cost per      Cost on U.S.
                Action                         Labor cost           Parts cost        product        operators
----------------------------------------------------------------------------------------------------------------
Borescope inspection of stage 6 seal    4 work-hours x $85 per                $0            $340              $0
 ring and interstage 5-6 seal teeth      hour = $340.
 forward and aft faces only.
----------------------------------------------------------------------------------------------------------------

    We estimate the following costs to do any necessary replacements 
that would be required based on the results of the inspection. We have 
no way of determining the number of aircraft that might need these 
replacements:

                                               On-Condition Costs
----------------------------------------------------------------------------------------------------------------
                                                                                                     Cost per
                   Action                                 Labor cost                Parts cost        product
----------------------------------------------------------------------------------------------------------------
Replacement of HPC stages 2 to 5 spool.....  8 work-hours x $85 per hour = $680.        $346,540        $347,220
----------------------------------------------------------------------------------------------------------------

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.
    This AD is issued in accordance with authority delegated by the 
Executive Director, Aircraft Certification Service, as authorized by 
FAA Order 8000.51C. In accordance with that order, issuance of ADs is 
normally a function of the Compliance and Airworthiness Division, but 
during this transition period, the Executive Director has delegated the 
authority to issue ADs applicable to engines, propellers, and 
associated appliances to the Manager, Engine and Propeller Standards 
Branch, Policy and Innovation Division.

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

[[Page 66611]]

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, 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):

AD 2018-22-07 Engine Alliance: Amendment 39-19480; Docket No. FAA-
2018-0938; Product Identifier 2018-NE-36-AD.

(a) Effective Date

    This AD is effective January 11, 2019.

(b) Affected ADs

    None.

(c) Applicability

    This AD applies to all Engine Alliance (EA) GP7270, GP7272, and 
GP7277 model turbofan engines.

(d) Subject

    Joint Aircraft System Component (JASC) Code 7230, Turbine Engine 
Compressor Section.

(e) Unsafe Condition

    This AD was prompted by a shop finding of axial cracks in the 
interstage 5-6 seal teeth of the high-pressure compressor (HPC) 
stages 2-5 spool spacer arm, due to an incorrectly installed stage 6 
seal ring. We are issuing this AD to prevent failure of the HPC 
stage 5-6 seal teeth and uncontained HPC stages 2-5 spool release. 
The unsafe condition, if not addressed, could result in an 
uncontained failure of the HPC stages 2-5 spool, damage to the 
engine, and damage to the airplane.

(f) Compliance

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

(g) Required Actions

    (1) Borescope inspect the stage 6 seal ring location in 
accordance with the Accomplishment Instructions, paragraph 1.F, in 
EA Alert Service Bulletin (ASB) EAGP7-A72-395, Revision No. 2, dated 
August 2, 2018, and within the compliance times specified in Table 1 
to paragraph (g) of this AD. If the stage 6 seal ring is incorrectly 
installed, remove the HPC stages 2-5 spool from service within 50 
cycles and replace with a part eligible for installation.
    (2) Borescope inspect the interstage 5-6 seal tooth aft face and 
interstage 5-6 forward face for cracks and missing coating in 
accordance with the Accomplishment Instructions, paragraphs 2.C and 
2.E, in EA ASB EAGP7-A72-395, Revision No. 2, dated August 2, 2018, 
and within the compliance times specified in Table 1 to paragraph 
(g) of this AD.
    (i) If coating is missing on the interstage 5-6 seal tooth 
forward or aft faces, repeat the borescope inspection required by 
paragraph (g)(2) of this AD for cracks every 150 cycles.
    (ii) If cracks are found in the interstage 5-6 seal tooth 
forward or aft faces, remove the HPC stages 2-5 spool from service 
and replace with a part eligible for installation before further 
flight.
[GRAPHIC] [TIFF OMITTED] TR27DE18.041

(h) Alternative Methods of Compliance (AMOCs)

    (1) The Manager, ECO Branch, FAA, has the authority to approve 
AMOCs for this AD, if requested using the procedures found in 14 CFR 
39.19. In accordance with 14 CFR 39.19, send your request to your 
principal inspector or local Flight Standards District Office, as 
appropriate. If sending information directly to the manager of the 
certification office, send it to the attention of the person 
identified in paragraph (i) of this AD. You may email your request 
to: [email protected].
    (2) Before using any approved AMOC, notify your appropriate 
principal inspector, or lacking a principal inspector, the manager 
of the local flight standards district office/certificate holding 
district office.

(i) Related Information

    For more information about this AD, contact Matthew Smith, 
Aerospace Engineer, ECO Branch, FAA, 1200 District Avenue, 
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) Engine Alliance (EA) Alert Service Bulletin EAGP7-A72-395, 
Revision No. 2, dated August 2, 2018.
    (ii) [Reserved]

[[Page 66612]]

    (3) For EA service information identified in this AD, contact 
Engine Alliance, 411 Silver Lane, East Hartford, CT 06118; phone: 
800-565-0140; email: [email protected]; website: 
www.engineallianceportal.com.
    (4) You may view this service information at FAA, Engine and 
Propeller Standards Branch, 1200 District Avenue, Burlington, MA 
01803. For information on the availability of this material at the 
FAA, call 781-238-7759.
    (5) You may view this service information that is incorporated 
by reference 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 December 19, 2018.
Robert J. Ganley,
Manager, Engine and Propeller Standards Branch, Aircraft Certification 
Service.
[FR Doc. 2018-27926 Filed 12-26-18; 8:45 am]
BILLING CODE 4910-13-P