[Federal Register Volume 88, Number 111 (Friday, June 9, 2023)]
[Rules and Regulations]
[Pages 37760-37762]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2023-12287]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2023-1205; Project Identifier AD-2023-00441-E; 
Amendment 39-22452; AD 2023-11-06]
RIN 2120-AA64


Airworthiness Directives; Engine Alliance Engines

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule; request for comments.

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SUMMARY: The FAA is adopting a new airworthiness directive (AD) for 
certain Engine Alliance (EA) Model GP7270, GP7272, and GP7277 engines. 
This AD was prompted by a manufacturer investigation that revealed that 
certain high-pressure turbine (HPT) interstage seals were manufactured 
from material suspected to contain iron inclusion. This AD requires 
replacement of the affected HPT interstage seals. The FAA is issuing 
this AD to address the unsafe condition on these products.

DATES: This AD is effective June 26, 2023.
    The FAA must receive comments on this AD by July 24, 2023.

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 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.
    AD Docket: You may examine the AD docket at regulations.gov by 
searching for and locating Docket No. FAA-2023-1205; 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, any 
comments received, and other information. The street address for Docket 
Operations is listed above.

FOR FURTHER INFORMATION CONTACT: Alexei Marqueen, Aviation Safety 
Engineer, FAA, 2200 South 216th Street, Des Moines, WA 98198; phone: 
(781) 238-7178; email: [email protected].

SUPPLEMENTARY INFORMATION: 

Background

    The FAA was notified by the manufacturer of the detection of iron 
inclusion in a turbine disk manufactured from the same material used to 
manufacture certain HPT interstage seals for EA Model GP7270, GP7272, 
and GP7277 engines. Further investigation by the manufacturer 
determined that the iron inclusion is attributed to deficiencies in the 
manufacturing process. The investigation by the manufacturer also 
determined that certain GP7270, GP7272, and GP7277 HPT interstage seals 
made from billets manufactured using the same process may have reduced 
material properties and a lower fatigue life capability due to iron 
inclusion, which may cause premature fracture and subsequent 
uncontained failure. This condition, if not addressed, could result in 
uncontained debris release, damage to the engine, and damage to the 
airplane. The FAA is issuing this AD to address the unsafe condition on 
these products.

FAA's Determination

    The FAA is issuing this AD because the agency has 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 replacement of certain HPT interstage seals with a 
part eligible for installation.

Interim Action

    The FAA considers this AD to be an interim action. This unsafe 
condition is still under investigation by the manufacturer and, 
depending on the results of that investigation, the FAA may consider 
further rulemaking action.

Justification for Immediate Adoption and Determination of the Effective 
Date

    Section 553(b)(3)(B) of the Administrative Procedure Act (APA) (5 
U.S.C. 551 et seq.) authorizes agencies to dispense with notice and 
comment procedures for rules when the agency, for ``good cause,'' finds 
that those procedures are ``impracticable, unnecessary, or contrary to 
the public interest.'' Under this section, an agency, upon finding good 
cause, may issue a final rule without providing notice and seeking 
comment prior to issuance. Further, section 553(d) of the APA 
authorizes agencies to make rules effective in less than thirty days, 
upon a finding of good cause.

[[Page 37761]]

    The FAA justifies waiving notice and comment prior to adoption of 
this rule because no domestic operators use this product. It is 
unlikely that the FAA will receive any adverse comments or useful 
information about this AD from any U.S. operator. Accordingly, notice 
and opportunity for prior public comment are unnecessary, pursuant to 5 
U.S.C. 553(b)(3)(B). In addition, for the foregoing reason(s), the FAA 
finds that good cause exists pursuant to 5 U.S.C. 553(d) for making 
this amendment effective in less than 30 days.

Comments Invited

    The FAA invites you to send any written data, views, or arguments 
about this final rule. Send your comments to an address listed under 
ADDRESSES. Include ``FAA-2023-1205 and Project Identifier AD-2023-
00441-E'' at the beginning of your comments. The most helpful comments 
reference a specific portion of the final rule, explain the reason for 
any recommended change, and include supporting data. The FAA will 
consider all comments received by the closing date and may amend this 
final rule because of those comments.
    Except for Confidential Business Information (CBI) as described in 
the following paragraph, and other information as described in 14 CFR 
11.35, the FAA will post all comments received, without change, to 
regulations.gov, including any personal information you provide. The 
agency will also post a report summarizing each substantive verbal 
contact received about this final rule.

Confidential Business Information

    CBI is commercial or financial information that is both customarily 
and actually treated as private by its owner. Under the Freedom of 
Information Act (FOIA) (5 U.S.C. 552), CBI is exempt from public 
disclosure. If your comments responsive to this AD contain commercial 
or financial information that is customarily treated as private, that 
you actually treat as private, and that is relevant or responsive to 
this AD, it is important that you clearly designate the submitted 
comments as CBI. Please mark each page of your submission containing 
CBI as ``PROPIN.'' The FAA will treat such marked submissions as 
confidential under the FOIA, and they will not be placed in the public 
docket of this AD. Submissions containing CBI should be sent to Alexei 
Marqueen, Aviation Safety Engineer, FAA, 2200 South 216th Street, Des 
Moines, WA 98198. Any commentary that the FAA receives which is not 
specifically designated as CBI will be placed in the public docket for 
this rulemaking.

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 FAA has determined 
that it has good cause to adopt this rule without prior notice and 
comment, RFA analysis is not required.

Costs of Compliance

    The FAA estimates that this AD affects 0 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
--------------------------------------------------------------------------------------------------------------------------------------------------------
Replace HPT interstage seal..............  8 work-hours x $85 per hour  $273,694 (pro-rated)............................        $274,374              $0
                                            = $680.
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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.

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.

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:

2023-11-06 Engine Alliance: Amendment 39-22452; Docket No. FAA-2023-
1205; Project Identifier AD-2023-00441-E.

(a) Effective Date

    This airworthiness directive (AD) is effective June 26, 2023.

(b) Affected ADs

    None.

(c) Applicability

    This AD applies to Engine Alliance Model GP7270, GP7272, and 
GP7277 engines with an installed high-pressure turbine (HPT) 
interstage seal having part number (P/N) 2047M99P02 and serial 
number (S/N) BTB71863 or BTB86871.

(d) Subject

    Joint Aircraft System Component (JASC) Code 7250, Turbine 
Section.

(e) Unsafe Condition

    This AD was prompted by a manufacturer investigation that 
revealed that certain HPT interstage seals were manufactured from 
material suspected to contain iron inclusion. The FAA is issuing 
this AD to prevent fracture and subsequent uncontained failure

[[Page 37762]]

of certain HPT interstage seals. The unsafe condition, if not 
addressed, could result in uncontained debris release, 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

    At the next piece-part exposure of the affected HPT interstage 
seal or before the affected HPT interstage seal exceeds 4,200 cycles 
since new, whichever occurs first after the effective date of this 
AD, remove the affected HPT interstage seal from service and replace 
with a part eligible for installation.

(h) Definition

    (1) For the purpose of this AD, a ``part eligible for 
installation'' is any HPT interstage seal that does not have a P/N 
and S/N identified in paragraph (c) of this AD.
    (2) For the purpose of this AD, ``piece-part exposure'' is when 
the affected part is removed from the engine and completely 
disassembled.

(i) Alternative Methods of Compliance (AMOCs)

    (1) The Manager, AIR-520 Continued Operational Safety 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 branch, send it to the 
attention of the person identified in paragraph (j) of this AD and 
email 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.

(j) Related Information

    For more information about this AD, contact Alexei Marqueen, 
Aviation Safety Engineer, FAA, 2200 South 216th Street, Des Moines, 
WA 98198; phone: (781) 238-7178; email: [email protected].

(k) Material Incorporated by Reference

    None.

    Issued on June 2, 2023.
Michael Linegang,
Acting Director, Compliance & Airworthiness Division, Aircraft 
Certification Service.
[FR Doc. 2023-12287 Filed 6-8-23; 8:45 am]
BILLING CODE 4910-13-P


