DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2021-0946; Project Identifier MCAI-2021-01020-E;
Amendment 39-21793; AD 2021-22-20]
Airworthiness Directives; Austro Engine GmbH Engines
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Final rule; request for comments.
SUMMARY: The FAA is adopting a new airworthiness directive (AD)
certain Austro Engine GmbH E4 and E4P model diesel piston engines. This
AD was prompted by reports of failure of the high-pressure pump (HPP)
driving gear and a subsequent determination that a batch of HPP driving
gears may have been damaged during assembly. This AD requires, for
engines with an affected cylinder head, inspection of the HPP driving
gear and, depending on the results of the inspection, replacement of
the HPP driving gear with a part eligible for installation. This AD
also requires, for engines with an affected HPP driving gear,
replacement of the HPP driving gear either before further flight or
within a certain number of flight hours after the effective date of
this AD. The FAA is issuing this AD to address the unsafe condition on
DATES: This AD is effective November 16, 2021.
The Director of the Federal Register approved the incorporation by
reference of certain publications listed in this AD as of November 16,
The FAA must receive comments on this AD by December 16, 2021.
ADDRESSES: You may send comments, using the procedures found in
11.43 and 11.45, by any of the following methods:
Federal eRulemaking Portal: Go to https://www.regulations.gov. Follow
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.
For service information identified in this final rule, contact
Austro Engine GmbH, Rudolf-Diesel-Strasse 11, 2700 Weiner Neustadt,
Austria; phone: +43 2622 23000; website: www.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 (781) 238-7759. It is also available at https://www.regulations.gov
searching for and locating Docket No. FAA-2021-0946.
Examining the AD Docket
You may examine the AD docket at https://www.regulations.gov by
searching for and locating Docket No. FAA-2021-0946; 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 street address for the Docket
Operations is listed above.
FOR FURTHER INFORMATION CONTACT: Wego Wang, Aviation Safety Engineer,
ECO Branch, FAA, 1200 District Avenue, Burlington, MA 01803; phone:
(781) 238-7134; fax: (781) 238-7199; email: email@example.com.
The European Union Aviation Safety Agency (EASA), which is the
Technical Agent for the Member States of the European Community, issued
EASA AD 2021-0203R1, dated September 24, 2021 (referred to after this
as ``the MCAI''), for Austro Engine GmbH E4 and E4P model diesel piston
engines, to address the unsafe condition on these products. The MCAI
Occurrences were reported of HPP driving gear failure.
Subsequent investigation determined that a certain batch of HPP
driving gears was produced with a worn out assembly tool P/N
AE300T012-1. Those HPP driving gears may have been damaged during
assembly. Concurrently, it was determined that, for engines equipped
with a certain cylinder head, a stack up of tolerances exists
between the cylinder head, cylinder head cover, camshaft gear and
HPP gear. Both scenarios could result in premature HPP gear failure.
This condition, if not corrected, could lead to engine in-flight
shut-down with consequent forced landing, possibly resulting in
damage to the aeroplane and injury to occupants. To address this
potential unsafe condition, Austro Engine published the inspection
SB, as defined in this [EASA] AD, to provide instructions for HPP
gear inspection on engines equipped with an affected cylinder head,
as defined in this [EASA] AD. Austro Engine also published the
replacement SB, as defined in this [EASA] AD, to provide
instructions for replacement of affected HPP gears, as defined in
this [EASA] AD. For the reason described above, EASA issued
Emergency AD 2021-0203-E to require inspection and/or replacement of
You may obtain further information by examining the MCAI in the AD
docket at https://www.regulations.gov by searching for and locating
Docket No. FAA-2021-0946.
This product has been approved by EASA and is approved for
operation in the United States. Pursuant to our bilateral agreement
with the European Community, EASA has notified the FAA of the unsafe
condition described in the MCAI. The FAA is issuing this AD because the
agency evaluated all the relevant information provided by EASA and has
determined that the unsafe condition described previously is likely to
exist or develop in other products of the same type design.
Related Service Information Under 1 CFR Part 51
The FAA reviewed Austro Engine Mandatory Service Bulletin No. MSB-
E4-035/1, Revision No. 1, dated September 30, 2021 (MSB-E4-035/1); and
Austro Engine Mandatory Service Bulletin No. MSB-E4-034/3, Revision No.
3, dated September 30, 2021 (MSB-E4-034/3).
Austro Engine MSB-E4-035/1 specifies procedures for inspecting HPP
driving gears installed on E4 and E4P
model diesel piston engines equipped with an affected cylinder head.
Austro Engine MSB-E4-034/3 identifies the applicable part number
and serial numbers of affected HPP driving gears installed on Austro
Engine GmbH E4 and E4P model diesel piston engines.
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.
This AD requires, for engines with an affected cylinder head,
inspection of the HPP driving gear and, depending on the results of the
inspection, replacement of the HPP driving gear with a part eligible
for installation. This AD also requires, for engines with an affected
HPP driving gear, replacement of the HPP driving gear within a certain
number of flight hours, depending on the airplane on which the affected
engine is installed.
Differences Between This AD and the MCAI
The MCAI requires replacement of the HPP driving gear using the
Accomplishment/Instructions, paragraph 2.1., of Austro Engine MSB-E4-
034/3 while this AD does not require use of MSB-E4-034/3 to replace the
HPP driving gear.
Justification for Immediate Adoption and Determination of the Effective
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.
An unsafe condition exists that requires the immediate adoption of
this AD without providing an opportunity for public comments prior to
adoption. The FAA has found that the risk to the flying public
justifies foregoing notice and comment prior to adoption of this rule.
The FAA received a report of occurrences of failure of the HPP driving
gear. The manufacturer subsequently determined that a certain batch of
HPP driving gears was produced with a worn out assembly tool, and may
have been damaged during assembly. The manufacturer also determined
that, for engines equipped with a certain cylinder head, a stack up of
tolerances exists between the cylinder head, cylinder head cover,
camshaft gear and high pressure pump driving gear. Both conditions
could result in failure of the HPP driving gear. Austro Engine
subsequently issued service information providing instructions for
inspection and replacement of certain HPP driving gears installed on E4
and E4P model diesel piston engines.
Failure of the HPP driving gear can result in in-flight engine
shut-down, forced landing, and damage to the airplane. The FAA
considers failure of the HPP driving gear to be an urgent safety issue
that requires immediate action to avoid damage to the airplane. For
engines with an affected cylinder head, if the HPP driving gear does
not pass the inspection required by this AD, this AD requires
replacement of the HPP driving gear before further flight. In addition,
for engines with an affected HPP driving gear and with a certain number
of hours accumulated on the HPP driving gear, this AD also requires
replacement of the HPP driving gear before further flight. Accordingly,
notice and opportunity for prior public comment are impracticable and
contrary to the public interest pursuant to 5 U.S.C. 553(b)(3)(B).
In addition, 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,
for the same reasons the FAA found good cause to forgo notice and
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 ``Docket No. FAA-2021-0946 and Project Identifier
MCAI-2021-01020-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
https://www.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 Wego
Wang, Aviation Safety Engineer, ECO Branch, FAA, 1200 District Avenue,
Burlington, MA 01803. Any commentary that the FAA receives which is not
specifically designated as CBI will be placed in the public docket for
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 418 engines installed on
airplanes of U.S. registry.
The FAA estimates the following costs to comply with this AD:
||Cost on U.S.
|Inspect HPP driving gear
||.5 work-hours x $85 per hour
|Replace HPP driving gear (for
engines with an affected HPP driving gear)
||2 work-hours x $85 per hour =
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 this replacement:
||Cost per product
|Replace HPP driving gear (for
engines with an affected
||2 work-hours x $85 per hour =
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
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 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
Accordingly, under the authority delegated to me by the
Administrator, the FAA amends 14 CFR part 39 as follows:
PART 39--AIRWORTHINESS DIRECTIVES
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]
2. The FAA amends Sec. 39.13 by adding the following new airworthiness