
[Federal Register Volume 88, Number 207 (Friday, October 27, 2023)]
[Proposed Rules]
[Pages 73778-73780]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2023-23634]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2023-2002; Project Identifier MCAI-2023-00176-E]
RIN 2120-AA64


Airworthiness Directives; GE Aviation Czech s.r.o. (Type 
Certificate Previously Held by WALTER Engines a.s., Walter a.s., and 
MOTORLET a.s.) Engines

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: The FAA proposes to supersede airworthiness directive (AD) 
2021-13-07, which applies to all GE Aviation Czech s.r.o. (GEAC) (type 
certificate previously held by WALTER Engine a.s., Walter a.s., and 
MOTORLET a.s.) Model M601D-11, M601E-11, M601E-11A, M601E-11AS, M601E-
11S, and M601F engines. AD 2021-13-07 requires recalculating the life 
of critical parts and, depending on the results of the recalculation, 
replacing these critical parts. AD 2021-13-07 also requires replacing a 
certain compressor case. Since the FAA issued AD 2021-13-07, the 
manufacturer published the airworthiness limitations section (ALS) of 
the existing engine maintenance manual (EMM), which includes the 
calculations for the life of critical parts addressed by AD 2021-13-07 
and prompted this proposed AD. This proposed AD would continue to 
require the replacement of a certain centrifugal compressor case. This 
proposed AD would also include an additional part number as an option 
for the replacement and would limit the applicability of the proposed 
AD, as specified in a European Union Aviation Safety Agency (EASA) AD, 
which is proposed for incorporation by reference (IBR). The FAA is 
proposing this AD to address the unsafe condition on these products.

DATES: The FAA must receive comments on this NPRM by December 11, 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 under 
Docket No. FAA-2023-2002; 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 NPRM, the mandatory continuing airworthiness 
information (MCAI), any comments received, and other information. The 
street address for Docket Operations is listed above.
    Material Incorporated by Reference:
     For service information identified in this NPRM, contact 
EASA, Konrad-Adenauer-Ufer 3, 50668 Cologne, Germany; phone: +49 221 
8999 000; email: [email protected]; website: easa.europa.eu. You may 
find this material on the EASA website at ad.easa.europa.eu. It is also 
available at regulations.gov under Docket No. FAA-2023-2002.
     You may view this service information at the FAA, 
Airworthiness Products Section, Operational Safety Branch, 1200 
District Avenue, Burlington, MA 01803. For information on the 
availability of this material at the FAA, call (817) 222-5110.

FOR FURTHER INFORMATION CONTACT: Barbara Caufield, Aviation Safety 
Engineer, FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590; 
phone: (781) 238-7146; email: [email protected].

SUPPLEMENTARY INFORMATION:

Comments Invited

    The FAA invites you to send any written relevant data, views, or 
arguments about this proposal. Send your comments to an address listed 
under ADDRESSES. Include ``Docket No. FAA-2023-2002; Project Identifier 
MCAI-2023-00176-E'' at the beginning of your comments. The most helpful 
comments reference a specific portion of the proposal, 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 
the proposal 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 NPRM.

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 NPRM 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 NPRM, 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 NPRM. Submissions containing CBI should be sent to 
Barbara Caufield, Aviation Safety Engineer, FAA, 1600 Stewart Avenue, 
Suite 410, Westbury, NY 11590. Any commentary that the

[[Page 73779]]

FAA receives which is not specifically designated as CBI will be placed 
in the public docket for this rulemaking.

Background

    The FAA issued AD 2021-13-07, Amendment 39-21612 (86 FR 31601, June 
15, 2021) (AD 2021-13-07), for all GEAC Model M601D-11, M601E-11, 
M601E-11A, M601E-11AS, M601E-11S, and M601F engines. AD 2021-13-07 was 
prompted by an MCAI originated by EASA, which is the Technical Agent 
for the Member States of the European Union. EASA issued EASA Emergency 
AD 2021-0125-E, dated May 7, 2021 (EASA Emergency AD 2021-0125-E) to 
address an unsafe condition identified as the manufacturer finding 
errors in the ALS of the existing EMM, including errors in the formula 
to determine the consumed equivalent flight cycles of critical parts 
and errors with certain part numbers. The manufacturer also determined 
that the life limit of a certain compressor case installed on Model 
M601E engines is not listed in the ALS of the applicable EMM.
    AD 2021-13-07 requires recalculating the life of critical parts 
and, depending on the results of the recalculation, replacing critical 
parts. AD 2021-13-07 also requires replacing a certain compressor case. 
The FAA issued AD 2021-13-07 to prevent the failure of the engine.

Actions Since AD 2021-13-07 Was Issued

    Since the FAA issued AD 2021-13-07, EASA revised EASA Emergency AD 
2021-0125-E and issued EASA AD 2021-0125R1, dated January 30, 2023 
(EASA AD 2021-0125R1) (referred to after this as the MCAI). The MCAI 
states that the manufacturer published the ALS, which incorporates 
certain requirements addressed by EASA Emergency AD 2021-0125-E, and 
that EASA published EASA AD 2023-0020, dated January 23, 2023 (EASA AD 
2023-0020), which requires accomplishment of the actions specified in 
the ALS. The MCAI limits the applicability to M601E engines with a 
centrifugal compressor case having part number M601-154.61 installed 
and removes the requirements that have been incorporated in the ALS. 
The FAA is addressing the actions specified in the ALS concurrently in 
a separate AD action.
    You may examine the MCAI in the AD docket at regulations.gov under 
Docket No. FAA-2023-2002.

Related Service Information Under 1 CFR Part 51

    The FAA reviewed EASA AD 2021-0125R1, which specifies procedures 
for replacing the centrifugal compressor case, limits the applicability 
to certain M601E engines, and removes the requirements that have been 
incorporated in the ALS.
    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 ADDRESSES.

FAA's Determination

    These products have been approved by the aviation authority of 
another country and are approved for operation in the United States. 
Pursuant to the FAA's bilateral agreement with this State of Design 
Authority, it has notified the FAA of the unsafe condition described in 
the MCAI referenced above. The FAA is issuing this NPRM after 
determining that the unsafe condition described previously is likely to 
exist or develop on other products of the same type design.

Proposed AD Requirements in This NPRM

    This proposed AD would require accomplishing the actions specified 
in the MCAI described previously, except for any differences identified 
as exceptions in the regulatory text of this proposed AD and the 
``Differences Between This Proposed AD and the MCAI.''

Differences Between This Proposed AD and the MCAI

    The MCAI applies to GEAC Model M601E engines, and this AD does not 
because they do not have an FAA type certificate.

Explanation of Required Compliance Information

    In the FAA's ongoing efforts to improve the efficiency of the AD 
process, the FAA developed a process to use some civil aviation 
authority (CAA) ADs as the primary source of information for compliance 
with requirements for corresponding FAA ADs. The FAA has since 
coordinated with other manufacturers and CAAs to use this process. As a 
result, the FAA proposes to incorporate by reference EASA AD 2021-
0125R1 in the FAA final rule. This proposed AD would, therefore, 
require compliance with EASA AD 2021-0125R1 in its entirety through 
that incorporation, except for any differences identified as exceptions 
in the regulatory text of this proposed AD. Using common terms that are 
the same as the heading of a particular section in the EASA AD does not 
mean that operators need comply only with that section. For example, 
where the AD requirement refers to ``all required actions within the 
compliance times,'' compliance with this AD requirement is not limited 
to the section titled ``Required Action(s) and Compliance Time(s)'' in 
EASA AD 2021-0125R1. Service information required by the EASA AD for 
compliance will be available at regulations.gov by under Docket No. 
FAA-2023-2002 after the FAA final rule is published.

Costs of Compliance

    The FAA estimates that this AD, if adopted as proposed, would 
affect 13 engines installed on airplanes of U.S. registry.
    The FAA estimates the following costs to comply with this proposed 
AD:

                                                 Estimated Costs
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                                                                                     Cost per      Cost on U.S.
                Action                         Labor cost           Parts cost        product        operators
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Recalculate centrifugal compressor      1 work-hour x $85 per                 $0             $85          $1,105
 case equivalent flight cycles.          hour = $85.
Replace centrifugal compressor case...  10 work-hours x $85 per           65,000          65,850         856,050
                                         hour = $850.
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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

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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

    The FAA 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 that the proposed 
regulation:
    (1) Is not a ``significant regulatory action'' under Executive 
Order 12866,
    (2) Would not affect intrastate aviation in Alaska, and
    (3) Would 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:
0
a. Removing Airworthiness Directive 2021-13-07, Amendment 39-21612 (86 
FR 31601, June 15, 2021); and
0
b. Adding the following new airworthiness directive:

GE Aviation Czech s.r.o. (Type Certificate Previously held by WALTER 
Engines a.s., Walter a.s., and MOTORLET a.s.): Docket No. FAA-2023-
2002; Project Identifier MCAI-2023-00176-E.

(a) Comments Due Date

    The FAA must receive comments on this airworthiness directive 
(AD) by December 11, 2023.

(b) Affected ADs

    This AD replaces AD 2021-13-07, Amendment 39-21612 (86 FR 31601, 
June 15, 2021).

(c) Applicability

    This AD applies to GE Aviation Czech s.r.o. (type certificate 
previously held by WALTER Engines a.s., Walter a.s., and MOTORLET 
a.s.) Model M601E-11, M601E-11A, M601E-11AS, and M601E-11S engines 
with a centrifugal compressor case having part number (P/N) M601-
154.61 installed.

(d) Subject

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

(e) Unsafe Condition

    This AD was prompted by the manufacturer determining that the 
life limit of a compressor case having P/N M601-154.61 is not listed 
in the airworthiness limitations section of the existing engine 
maintenance manual. The FAA is issuing this AD to prevent the 
failure of the engine. The unsafe condition, if not addressed, could 
result in uncontained release of a critical part, 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

    Except as specified in paragraph (h) of this AD: Perform all 
required actions within the compliance times specified in, and in 
accordance with, European Union Aviation Safety Agency (EASA) AD 
2021-0125R1, dated January 30, 2023 (EASA AD 2021-0125R1).

(h) Exceptions to EASA AD 2021-0125R1

    (1) Where EASA AD 2021-0125R1 refers to May 11, 2021 (the 
effective date of EASA Emergency AD 2021-0125-E, dated May 7, 2021), 
this AD requires using June 30, 2021 (the effective date of AD 2021-
13-07).
    (2) This AD does not adopt the Remarks paragraph of EASA AD 
2021-0125R1.

(i) Alternative Methods of Compliance (AMOCs)

    (1) The Manager, International Validation 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 International Validation 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) Additional Information

    For more information about this AD, contact Barbara Caufield, 
Aviation Safety Engineer, FAA, 1600 Stewart Avenue, Suite 410, 
Westbury, NY 11590; phone: (781) 238-7146; 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) European Union Aviation Safety Agency (EASA) AD 2021-0125R1, 
dated January 30, 2023.
    (ii) [Reserved]
    (3) For EASA AD 2021-0125R1, contact EASA, Konrad-Adenauer-Ufer 
3, 50668 Cologne, Germany; phone: +49 221 8999 000; email: 
[email protected]; website: easa.europa.eu. You may find this EASA 
AD on the EASA website at ad.easa.europa.eu.
    (4) You may view this service information at FAA, Airworthiness 
Products Section, Operational Safety Branch, 1200 District Avenue, 
Burlington, MA 01803. For information on the availability of this 
material at the FAA, call (817) 222-5110.
    (5) You may view this material at the National Archives and 
Records Administration (NARA). For information on the availability 
of this material at NARA, visit www.archives.gov/federal-register/cfr/[email protected]">www.archives.gov/federal-register/cfr/[email protected].

    Issued on October 19, 2023.
Ross Landes,
Deputy Director for Regulatory Operations, Compliance & Airworthiness 
Division, Aircraft Certification Service.
[FR Doc. 2023-23634 Filed 10-26-23; 8:45 am]
BILLING CODE 4910-13-P


