
[Federal Register Volume 88, Number 213 (Monday, November 6, 2023)]
[Rules and Regulations]
[Pages 76104-76107]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2023-24385]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2023-1412; Project Identifier MCAI-2022-01588-E; 
Amendment 39-22562; AD 2023-20-03]
RIN 2120-AA64


Airworthiness Directives; Austro Engine GmbH Engines

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule.

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SUMMARY: The FAA is adopting a new airworthiness directive (AD) for 
certain Austro Engine GmbH Model E4 and E4P engines. This AD is 
prompted by reports of piston failures and the determination that 
certain batches of pistons were manufactured with a dimensional 
deviation in the piston pin bore and piston diameter. This AD requires 
repetitive engine oil analysis for aluminum content outside the 
acceptable limits and, if necessary, replacement of the pistons, piston 
rings, con-rods assembly, and crankcase or, as an alternative, 
replacement of the engine core. The FAA is issuing this AD to address 
the unsafe condition on these products.

DATES: This AD is effective December 11, 2023.
    The Director of the Federal Register approved the incorporation by 
reference of a certain publication listed in this AD as of December 11, 
2023.

ADDRESSES: 
    AD Docket: You may examine the AD docket at regulations.gov under 
Docket No.FAA-2023-1412; 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 mandatory continuing airworthiness 
information (MCAI), any comments received, and other information. The 
address for Docket Operations is U.S. Department of Transportation, 
Docket Operations, M-30, West Building Ground Floor, Room W12-140, 1200 
New Jersey Avenue SE, Washington, DC 20590.
    Material Incorporated by Reference:
     For service information identified in this final rule, 
contact Austro Engine GmbH, Rudolf-Diesel-Strasse 11, A-2700 Weiner 
Neustadt, Austria; phone: +43 2622 23000; website: austroengine.at.
     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. It is 
also available at regulations.gov under Docket No. FAA-2023-1412.

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: 

Background

    The FAA issued a notice of proposed rulemaking (NPRM) to amend 14 
CFR part 39 by adding an AD that would apply to certain Austro Engine 
GmbH Model E4 and E4P engines. The NPRM published in the Federal 
Register on July 14, 2023 (88 FR 45118). The NPRM was prompted by 
European Union Aviation Safety Agency (EASA) AD 2022-0240R1, dated 
December 15, 2022 (referred to after this as the MCAI), issued by EASA, 
which is the Technical Agent for the Member States of the European 
Union. The MCAI states that a manufacturer investigation into reports 
of piston failures determined that certain batches of pistons were 
manufactured with a dimensional deviation in the piston pin bore and in 
the piston diameter, which could cause piston failure, with consequent 
loss of oil, loss of engine power, and reduced control of the airplane. 
To address the unsafe condition, EASA issued EASA AD 2022-0240, dated 
December 6, 2022 (EASA AD 2022-0240), to specify repetitive oil 
analyses and replacement of the pistons, piston rings, con-rods 
assembly, and crankcase, or as an alternative, replacement of the 
engine core. EASA AD 2022-0240 also prohibited release to service of an 
airplane until receipt of the results for each oil analysis.
    Since EASA AD 2022-0240 was issued, the manufacturer determined 
that aluminum levels outside of the acceptable limits would be found 
during the first oil analysis, and are unlikely to be found during 
subsequent oil analyses. As a result, EASA revised

[[Page 76105]]

EASA AD 2022-0240 and issued the MCAI to allow release to service of 
airplanes for a limited number of flight hours immediately after the 
second and subsequent oil samples are taken for analyses.
    In the NPRM, the FAA proposed to require initial and repetitive 
engine oil analysis for aluminum content outside the acceptable limits 
and, if necessary, replacement of the pistons, piston rings, con-rods 
assembly, and crankcase, or as an alternative, replacement of the 
engine core. The FAA is issuing this AD to address the unsafe condition 
on these products.
    You may examine the MCAI in the AD docket at regulations.gov under 
Docket No. FAA-2023-1412.

Discussion of Final Airworthiness Directive

Comments

    The FAA received no comments on the NPRM or on the determination of 
the costs.

Conclusion

    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 reviewed the relevant data and 
determined that air safety requires adopting this AD as proposed. 
Accordingly, the FAA is issuing this AD to address the unsafe condition 
on these products. Except for minor editorial changes, this AD is 
adopted as proposed in the NPRM.

Related Service Information Under 1 CFR Part 51

    The FAA reviewed Austro Engine GmbH Mandatory Service Bulletin No. 
MSB-E4-039/1, Revision 1, dated April 24, 2023, which specifies 
procedures for oil analysis and replacement of the pistons, piston 
rings, con-rods assembly, crankcase, and engine core.
    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.

Costs of Compliance

    The FAA estimates that this AD affects 357 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
----------------------------------------------------------------------------------------------------------------
Oil Analysis........................  .25 work-hours x $85                 $0           $21.25        $7,586.25
                                       per hour = $21.25.
----------------------------------------------------------------------------------------------------------------

    The FAA estimates the following costs to do any necessary 
replacements that would be required based on the results of the 
inspection. The agency 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
----------------------------------------------------------------------------------------------------------------
Replace engine core...........................  50 work-hours x $85 per hour =           $15,524         $19,774
                                                 $4,250.
Replace pistons, piston rings, and con-rods     60 work-hours x 85 per hour =              2,216           7,316
 assembly.                                       5,100.
Replace pistons, piston rings, con-rods         70 work-hours x 85 per hour =              4,141          10,091
 assembly, and crankcase.                        5,950.
----------------------------------------------------------------------------------------------------------------

    The FAA has included all known costs in its cost estimate. 
According to the manufacturer, however, some of the costs of this AD 
may be covered under warranty, thereby reducing the cost impact on 
affected operators.

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,
    (2) Will not affect intrastate aviation in Alaska, and
    (3) 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.

The Amendment

    Accordingly, under the authority delegated to me by the 
Administrator, the FAA amends 14 CFR part 39 as follows:

[[Page 76106]]

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:

2023-20-03 Austro Engine GmbH: Amendment 39-22562; Docket No. FAA-
2023-1412; Project Identifier MCAI-2022-01588-E.

(a) Effective Date

    This airworthiness directive (AD) is effective December 11, 
2023.

(b) Affected ADs

    None.

(c) Applicability

    This AD applies to Austro Engine GmbH Model E4 and E4P engines 
with a serial number listed in Tables 1, 2, 3, and 4 of Austro 
Engine GmbH Mandatory Service Bulletin No. MSB-E4-039/1, Revision 1, 
dated April 24, 2023 (MSB-E4-039/1).

(d) Subject

    Joint Aircraft System Component (JASC) Codes 8530, Reciprocating 
Engine Cylinder Section; 8550, Reciprocating Engine Oil System.

(e) Unsafe Condition

    This AD was prompted by reports of piston failures and the 
determination that certain batches of pistons were manufactured with 
a dimensional deviation in the piston pin bore and piston diameter. 
The FAA is issuing this AD to prevent piston failure. The unsafe 
condition, if not addressed, could result in loss of oil, loss of 
engine power, and reduced control of the airplane.

(f) Compliance

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

(g) Required Actions

    (1) For all affected engines, within the applicable compliance 
times specified in Table 1 to paragraph (g)(1) of this AD, perform 
an oil analysis in accordance with paragraph 2., Technical Details, 
Engine Oil Analysis of MSB-E4-039/1, and do not return the engine to 
service until the results of the oil analysis have been determined.

   Table 1 to Paragraph (g)(1)--Oil Analysis for All Affected Engines
------------------------------------------------------------------------
        Engine group             Compliance time          Interval
------------------------------------------------------------------------
Group 1 and Group 3.........  Within 15 flight      Before exceeding 50
                               hours (FHs) from      FHs since last oil
                               the effective date    analysis.
                               of this AD.
Group 2 and Group 4.........  Within 25 FHs from    Before exceeding 100
                               the effective date    FHs since last oil
                               of this AD.           analysis.
------------------------------------------------------------------------

    (2) Thereafter, repeat the oil analysis required by paragraph 
(g)(1) of this AD before exceeding the applicable interval specified 
in Table 1 to paragraph (g)(1) of this AD.
    (3) Following each repetitive oil analysis, the engine may be 
returned to service for no more than the applicable interval 
specified in Table 1 to paragraph (g)(1) of this AD, until receipt 
of the oil analysis result.
    (4) If the result of any oil analysis required by paragraph 
(g)(1) of this AD indicates the aluminum content of the oil is 
greater than the limit specified in paragraph 2., Technical Details, 
Engine Oil Analysis, Table 5--Oil check analysis--Aluminum PPM 
allowable of MSB-E4-039/1, before further flight, replace the 
pistons, piston rings, con-rods assembly, and crankcase, or replace 
the engine core in accordance with paragraph 2., Technical Details, 
Engine core replacement; or Pistons, piston rings, crankcase and 
con-rod assy replacement; as applicable, of MSB-E4-039/1.
    (5) For Group 3 and Group 4 engines, within the applicable 
compliance times specified in Table 2 to paragraph (g)(5) of this 
AD, replace the pistons, piston rings, and con-rods assembly, or 
replace the engine core in accordance with paragraph 2., Technical 
Details, Engine core replacement; or Pistons, piston rings and con-
rod assy replacement, as applicable, of MSB-E4-039/1.

   Table 2 to Paragraph (g)(5)--Replacement for Groups 3 and 4 Engines
------------------------------------------------------------------------
            Engine group                       Compliance time
------------------------------------------------------------------------
Group 3............................  Before exceeding 900 FHs since new,
                                      or within 15 FHs after the
                                      effective date of this AD,
                                      whichever occurs later.
Group 4............................  Before exceeding 1,000 FHs since
                                      new, or within 25 FHs after the
                                      effective date of this AD,
                                      whichever occurs later.
------------------------------------------------------------------------

    Note 1 to paragraph (g)(5): FHs since new indicated in Table 2 
to paragraph (g)(5) of this AD are FHs accumulated by the engine 
since first installation on an airplane or since last overhaul as of 
the effective date of this AD.

(h) Terminating Action

    (1) Replacement of the pistons, piston rings, con-rods assembly, 
and crankcase, or replacement of the engine core, as specified in 
paragraph (g)(4) of this AD, constitutes terminating action for the 
repetitive oil analysis required by paragraph (g)(2) of this AD.
    (2) Replacement of the pistons, piston rings, and con-rods 
assembly, or replacement of the engine core, as specified in 
paragraph (g)(5) of this AD, constitutes terminating action for the 
repetitive oil analysis required by paragraph (g)(2) of this AD.

(i) Definitions

    (1) For the purpose of this AD, Group 1 engines are engines 
having a serial number (S/N) listed in Table 1 of MSB-E4-039/1.
    (2) For the purpose of this AD, Group 2 engines are engines 
having an S/N listed in Table 2 of MSB-E4-039/1.
    (3) For the purpose of this AD, Group 3 engines are engines 
having an S/N listed in Table 3 of MSB-E4-039/1.
    (4) For the purpose of this AD, Group 4 engines are engines 
having an S/N listed in Table 4 of MSB-E4-039/1.

(j) Credit for Previous Actions

    You may take credit for the actions required by paragraph 
(g)(1), (4), or (5) of this AD, if you performed those actions 
before the effective date of this AD using Austro Engine Mandatory 
Service Bulletin MSB-E4-039/0, dated October 24, 2022.

(k) 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 (l)(2) 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.

[[Page 76107]]

(l) Additional Information

    (1) Refer to European Union Aviation Safety Agency (EASA) AD 
2022-0240R1, dated December 15, 2022, for related information. This 
EASA AD may be found in the AD docket at regulations.gov under 
Docket No. FAA-2023-1412.
    (2) 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].

(m) Material Incorporated by Reference

    (1) The Director of the Federal Register approved the 
incorporation by reference 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) Austro Engine GmbH Mandatory Service Bulletin No. MSB-E4-
039/1, Revision 1, dated April 24, 2023.
    (ii) [Reserved]
    (3) For service information identified in this AD, contact 
Austro Engine GmbH, Rudolf-Diesel-Strasse 11, A-2700 Weiner 
Neustadt, Austria; phone: +43 2622 23000; website: austroengine.at.
    (4) 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.
    (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 20, 2023.
Ross Landes,
Deputy Director for Regulatory Operations, Compliance & Airworthiness 
Division, Aircraft Certification Service.
[FR Doc. 2023-24385 Filed 11-3-23; 8:45 am]
BILLING CODE 4910-13-P


