Document ID: FAA-2019-0459-0001
Agency: faa
Document Type: Rule
Title: Airworthiness Directives: Engine Alliance Turbofan Engines
Posted Date: 2019-08-15T04:00Z

[Federal Register Volume 84, Number 158 (Thursday, August 15, 2019)]
[Unknown Section]
[Pages 41632-41635]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2019-17499]

[[Page 41632]]

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2019-0459; Product Identifier 2018-NE-36-AD; Amendment 
39-19699; AD 2019-15-06]
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: The FAA is superseding Airworthiness Directive (AD) 2018-22-07 
for all Engine Alliance (EA) GP7270, GP7272, and GP7277 model turbofan 
engines. AD 2018-22-07 required inspection of the stage 6 seal ring for 
correct installation and inspection of the high-pressure compressor 
(HPC) stages 2-5 spool for cracks and, depending on the results of the 
inspections, replacement of the HPC stages 2-5 spool with a part 
eligible for installation. This AD requires the same inspections but 
reduces the inspection interval and adds a repetitive inspection and a 
mandatory terminating action. 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. The 
FAA is issuing this AD to address the unsafe condition on these 
products.

DATES: This AD is effective August 30, 2019.
    The Director of the Federal Register approved the incorporation by 
reference of certain publications listed in this AD as of August 30, 
2019.
    The FAA must receive any comments on this AD by September 30, 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-2019-0459.

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-2019-
0459; 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 Docket Operations 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

    The FAA issued AD 2018-22-07, Amendment 39-19480 (83 FR 66609, 
December 27, 2018), (``AD 2018-22-07'') for all EA GP7270, GP7272, and 
GP7277 model turbofan engines. AD 2018-22-07 required inspection of the 
stage 6 seal ring for correct installation and inspection of the HPC 
stages 2-5 spool for cracks and, depending on the results of the 
inspections, replacement of the HPC stages 2-5 spool with a part 
eligible for installation. AD 2018-22-07 resulted from a shop finding 
of axial cracks in the HPC interstage 5-6 seal teeth of the HPC stages 
2-5 spool spacer arm due to an incorrectly installed stage 6 seal ring. 
The FAA issued AD 2018-22-07 to prevent failure of the HPC interstage 
5-6 seal teeth and uncontained release of the HPC stages 2-5 spool.

Actions Since AD 2018-22-07 Was Issued

    Since the FAA issued AD 2018-22-07, EA identified additional cracks 
as a result of inspections required by AD 2018-22-07. After further 
analysis, EA identified a subpopulation of parts that had the HPC rotor 
assembly disassembled and reassembled, which require additional 
inspections. EA subsequently completed a new safety risk assessment 
and, based on the findings, decided to retain the previous inspections 
but also add repetitive inspections and an additional in-shop 
inspection as a terminating action. The in-shop inspections are a 
terminating action for the engines with HPC stages 2-5 spools 
identified in paragraph (g)(2) of this AD. The FAA is issuing this AD 
to address the unsafe condition on these products.

Related Service Information Under 1 CFR Part 51

    The FAA reviewed EA Alert Service Bulletin (ASB) EAGP7-A72-395, 
Revision No. 3, dated June 3, 2019; EA Service Bulletin (SB) EAGP7-72-
413, dated February 4, 2019; and EA SB EAGP7-72-398, dated February 4, 
2019. EA ASB EAGP7-A72-395 describes procedures for performing a 
borescope inspection (BSI) of the HPC stages 2-5 spool for cracks, 
visual inspection of the stage 6 seal ring for correct installation, 
visual inspection of the HPC interstage 5-6 seal teeth for damage, and 
removal and replacement of parts if damage is found outside serviceable 
limits. EA SB EAGP7-72-413 describes procedures for performing a 
repetitive BSI of the aft and forward HPC interstage 5-6 seal teeth for 
cracks or missing coating. EA SB EAGP7-72-398 describes procedures for 
performing an ECI and dimensional inspection of the HPC stages 2-5 
spool interstage 5-6 seal teeth for cracks. 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

    The FAA is issuing this AD because it 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 an initial inspection of the HPC stage 6 seal ring 
for correct installation and inspection of the HPC stages 2-5 spool for 
cracks or missing coating. This AD also requires repetitive on-wing 
inspections for a sub-population of HPT stages 2-5 spools. This AD 
requires removal and replacement of the HPC stages 2-5 spool if, as the 
result of any inspection required by this AD, the stage 6 seal ring is 
found installed incorrectly or the HPC

[[Page 41633]]

interstage 5-6 seal teeth are found cracked or are missing coating. As 
terminating action to the repetitive on-wing inspections, this AD 
requires additional in-shop inspections and replacement of the HPC 
stages 2-5 spool based on the results of those inspections.

FAA's Justification and Determination of the Effective Date

    No domestic operators use this product. Therefore, the FAA finds 
good cause that notice and opportunity for prior public comment are 
unnecessary. In addition, for the reason stated above, the FAA finds 
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 the FAA did not provide you with notice and an opportunity 
to provide your comments before it becomes effective. However, the FAA 
invites 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-2019-0459 and product identifier 
2018-NE-36-AD at the beginning of your comments. The FAA specifically 
invites comments on the overall regulatory, economic, environmental, 
and energy aspects of this final rule. The FAA will consider all 
comments received by the closing date and may amend this final rule 
because of those comments.
    The FAA will post all comments received, without change, to http://www.regulations.gov, including any personal information you provide. 
The FAA will also post a report summarizing each substantive verbal 
contact received about this final rule.

Regulatory Flexibility Act

    The requirements of the Regulatory Flexibility Act (RFA) do not 
apply when an agency finds good cause pursuant to 5 U.S.C. 553 to adopt 
a rule without prior notice and comment. Because the FAA has determined 
that it has good cause to adopt this rule without notice and comment, 
RFA analysis is not required.

Costs of Compliance

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

                                                 Estimated Costs
----------------------------------------------------------------------------------------------------------------
                                                                                     Cost per      Cost on U.S.
                Action                         Labor cost           Parts cost        product        operators
----------------------------------------------------------------------------------------------------------------
Initial BSI...........................  4 work-hours x $85 per                $0            $340              $0
                                         hour = $340.
Repetitive BSI........................  3 work-hours x $85 per                 0             255               0
                                         hour = $255.
In-shop terminating action............  6 work-hours x $85 per                 0             510               0
                                         hour = $510.
----------------------------------------------------------------------------------------------------------------

    The FAA estimates the following costs to do any necessary 
replacements that would be required based on the results of the 
inspection. The FAA has 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 2-5 spool...........  8 work-hours x $85 per hour =           $346,540        $347,220
                                                 $680.
----------------------------------------------------------------------------------------------------------------

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.
    The FAA is 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 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, and
    (2) Will not affect intrastate aviation in Alaska.

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 part 39 of the Federal Aviation 
Regulations (14 CFR part 39) as follows:

[[Page 41634]]

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 removing Airworthiness Directive (AD) 
2018-22-07, Amendment 39-19480 (83 FR 66609, December 27, 2018) and 
adding the following new AD:

2019-15-06 Engine Alliance: Amendment 39-19699; Docket No. FAA-2019-
0459; Product Identifier 2018-NE-36-AD.

(a) Effective Date

    This AD is effective August 30, 2019.

(b) Affected ADs

    This AD replaces AD 2018-22-07, Amendment 39-19480 (83 FR 66609, 
December 27, 2018).

(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. The FAA is issuing this AD to prevent failure of the HPC 
interstage 5-6 seal teeth and uncontained HPC stages 2-5 spool 
release. The unsafe condition, if not addressed, could result in an 
uncontained release 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) For all HPC stages 2-5 spools, perform an initial borescope 
inspection (BSI) of the HPC stage 6 seal ring position:
    (i) Borescope inspect the HPC stage 6 seal ring location in 
accordance with the Accomplishment Instructions, paragraph 1.F, of 
EA Alert Service Bulletin (ASB) EAGP7-A72-395, Revision No. 3, dated 
June 3, 2019, and within the compliance times specified in Table 1 
to paragraph (g)(1) of this AD or within 230 engine cycles after the 
effective date of this AD, whichever occurs first. If the HPC stage 
6 seal ring is installed incorrectly, remove the HPC stages 2-5 
spool from service within 50 engine cycles and replace with a part 
eligible for installation, and correct the location of the stage 6 
seal ring.
    (ii) Borescope inspect the HPC interstage 5-6 seal tooth forward 
and aft face for cracks and missing coating in accordance with the 
Accomplishment Instructions, paragraphs 2.C and 2.E, of EA ASB 
EAGP7-A72-395, Revision No. 3, dated June 3, 2019, and within the 
compliance times specified in Table 1 to paragraph (g)(1) of this AD 
or within 230 engine cycles after the effective date of this AD, 
whichever occurs first.
    (A) If the coating is missing on the HPC interstage 5-6 seal 
tooth forward or aft face, thereafter, repeat the BSI required by 
paragraph (g)(1)(ii) of this AD for cracks within every 150 engine 
cycles since you performed the last BSI.
    (B) If cracks are found in the HPC interstage 5-6 seal tooth 
forward or aft face, remove the HPC stages 2-5 spool from service 
and replace with a part eligible for installation before further 
flight.

              Table 1 to Paragraph (g)(1)--Compliance Times
------------------------------------------------------------------------
Cycles since new (CSN) on HPC stages
  2-5 spool as of January 11, 2019
 (the effective date of AD 2018-22-         Complete the inspection
                 07)
------------------------------------------------------------------------
2,499 or less.......................  Within 900 engine cycles after
                                       January 11, 2019, but not to
                                       exceed 2,850 CSN.
2,500 to 3,499......................  Within 350 engine cycles after
                                       January 11, 2019, but not to
                                       exceed 3,600 CSN.
3,500 or more.......................  Within 100 engine cycles after
                                       January 11, 2019.
------------------------------------------------------------------------

    (2) For HPC stages 2-5 spools listed in Table 1 of Appendix A of 
EA SB EAGP7-72-413, dated February 4, 2019, perform the following 
repetitive on-wing inspections:
    (i) Borescope inspect the HPC interstage 5-6 seal tooth forward 
and aft face for cracks and missing coating in accordance with the 
Accomplishment Instructions, paragraphs 1.E. and 1.G., of EA SB 
EAGP7-72-413, dated February 4, 2019, within 300 engine cycles after 
completion of the initial inspection required by paragraph 
(g)(1)(ii) of this AD. If the engine has already accumulated more 
than 200 engine cycles since the inspection required by paragraph 
(g)(1)(ii) of this AD, perform this BSI of the HPC interstage 5-6 
seal tooth forward and aft face within the next 100 engine cycles 
after the effective date of this AD, but before exceeding 500 engine 
cycles since the last inspection required by paragraph (g)(1)(ii) of 
this AD.
    (A) If the coating is found missing on the HPC interstage 5-6 
seal tooth forward or aft face during the BSI, thereafter, repeat 
the BSI required by paragraph (g)(2)(i) of this AD for cracks within 
every 150 engine cycles since last BSI required by paragraph 
(g)(2)(i).
    (B) If cracks are found in the HPC interstage 5-6 seal tooth 
forward or aft face during the BSI, remove the HPC stages 2-5 spool 
from service and replace with a part eligible for installation 
before further flight.
    (ii) Thereafter, repeat the BSI required by paragraph (g)(2)(i) 
of this AD at intervals not exceeding 300 engine cycles since the 
last BSI.

(h) Mandatory Terminating Action for HPC Stages 2-5 Spools Identified 
in Paragraph (g)(2) of This AD

    As a terminating action to the on-wing repetitive BSI required 
by paragraph (g)(2) of this AD, at the next engine shop visit after 
the effective date of this AD, perform the following inspections 
and, if necessary, replacement of any HPC stages 2-5 spools listed 
in Table 1 of Appendix A of EA SB EAGP7-72-413, dated February 4, 
2019.
    (1) Visually inspect for the location of the HPC stage 6 seal 
ring in accordance with the Accomplishment Instructions, paragraph 
1, of EA SB EAGP7-72-398, dated February 4, 2019. If the seal ring 
is found to be installed incorrectly, remove the HPC stages 2-5 
spool and the HPC stage 6 seal ring from service and replace with 
parts eligible for installation.
    (2) Perform an eddy current inspection (ECI) of the HPC 
interstage 5-6 seal teeth on the HPC stages 2-5 spool in accordance 
with Accomplishment Instructions, paragraph 2, of EA SB EAGP7-72-
398, dated February 4, 2019. If there are ECI indications, as 
defined in paragraph 2 of EA SB EAGP7-72-398, remove the HPC stages 
2-5 spool from service and replace with a part eligible for 
installation.
    (3) Dimensionally inspect the diameter of the middle tooth of 
the HPC interstage 5-6 seal teeth on eight equally spaced points of 
the HPC stages 2-5 spool in accordance with the Accomplishment 
Instructions, paragraph 3, of EA SB EAGP7-72-398, dated February 4, 
2019. If the average diameter is larger than the ``expected 
diameter,'' as defined in the Accomplishment Instructions, Figure 4 
and Figure 5, of EA SB EAGP7-72-398, dated February 4, 2019, remove 
the HPC stages 2-5 spool from service and replace with a part 
eligible for installation.

(i) Definition

    For the purpose of this AD, an ``engine shop visit'' is the 
induction of an engine into the shop for maintenance involving the 
separation of pairs of major mating engine case flanges, except for 
the following situations, which do not constitute an engine shop 
visit:

[[Page 41635]]

    (1) Separation of engine flanges solely for the purposes of 
transportation of the engine without subsequent maintenance.
    (2) Separation of engine flanges solely for the purpose of 
replacing the fan or propulsor without subsequent engine 
maintenance.

(j) No Reporting Requirement

    The reporting requirements in the Accomplishment Instructions, 
paragraphs 1 and 2 of EA SB EAGP7-72-398, dated February 4, 2019, 
are not required by this AD.

(k) Credit for Previous Actions

    You may take credit for any of the initial inspections required 
by paragraph (g)(1) of this AD if you performed the initial 
inspection before the effective date of this AD using EA ASB EAGP7-
A72-395, Revision No. 2, dated August 2, 2018. The repetitive 
inspections required by paragraph (g)(1) of this AD are still 
required if the HPC stage 6 seal ring position is installed 
incorrectly or the HPC interstage 5-6 seal tooth forward or aft face 
is cracked or missing coating as determined by the initial BSI 
required by paragraph (g)(1).

(l) 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 (m) 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.
    (3) AMOCs approved for AD 2018-22-07, Amendment 39-19480 (83 FR 
66609, December 27, 2018) are approved as AMOCs for paragraph (g)(1) 
of this AD.

(m) 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].

(n) 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. 3, dated June 3, 2019.
    (ii) EA Service Bulletin (SB) EAGP7-72-413, dated February 4, 
2019.
    (iii) EA SB EAGP7-72-398, dated February 4, 2019.
    (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 August 2, 2019.
Karen M. Grant,
Acting Manager, Engine and Propeller Standards Branch, Aircraft 
Certification Service.
[FR Doc. 2019-17499 Filed 8-14-19; 8:45 am]
 BILLING CODE 4910-13-P