DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2023-1809; Project Identifier MCAI-2023-00945-E;
Amendment 39-22539; AD 2023-17-13]
Airworthiness Directives; BRP-Rotax GmbH & Co KG (Formerly BRP-
POWERTRAIN GMBH & CO KG and Bombardier-Rotax GmbH) Engines and Various
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Final rule; request for comments.
SUMMARY: The FAA is adopting a new airworthiness directive (AD)
BRP-Rotax GmbH & Co KG (Rotax) Model 912 F2, 912 F3, 912 F4, 912 iSc2
Sport, 912 iSc3 Sport, 912 S2, 912 S3, 912 S4, 914 F2, 914 F3, and 914
F4 engines; and Model 912 A, 912 A2, and 912 A3 engines included as
part of the type certificated aircraft type design for various
aircraft. This AD was prompted by a report of surface abnormalities on
the affected propeller shaft, which could lead to increased wear of the
propeller shaft bearings. This AD requires initial and repetitive
inspections of the magnetic plug for the accumulation of metal chips to
assess the condition of the propeller gearbox for wear of the propeller
shaft bearings and removal of the affected propeller shaft from service
and replacement with a part eligible for installation as a terminating
action either immediately or at a certain time depending on inspection
findings. This AD also prohibits installation of the affected propeller
shaft on any engine. The FAA is issuing this AD to address the unsafe
condition on these products.
DATES: This AD is effective September 20, 2023.
The Director of the Federal Register approved the incorporation by
reference of certain publications listed in this AD as of September 20,
The FAA must receive comments on this AD by October 20, 2023.
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 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-2023-1809; 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 Docket Operations is listed above.
Material Incorporated by Reference:
For service information identified in this final rule,
contact BRP-Rotax GmbH & Co KG, Rotaxstrasse 1, A-4623 Gunskirchen,
Austria; phone: +43 7246 601 0; website: flyrotax.com.
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-2023-1809.
FOR FURTHER INFORMATION CONTACT: Barbara Caufield, Aviation Safety
Engineer, FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590;
phone: (781) 238-7146; email: firstname.lastname@example.org.
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-2023-1809; Project Identifier MCAI-
2023-00945-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 Barbara
Caufield, Aviation Safety Engineer, FAA, 1600 Stewart Avenue, Suite
410, Westbury, NY 11590. Any commentary that the FAA receives which is
not specifically designated as CBI will be placed in the public docket
for this rulemaking.
The European Union Aviation Safety Agency (EASA), which is the
Technical Agent for the Member States of the European Union, has issued
EASA Emergency AD 2023-0156-E, dated August 2, 2023 (referred to after
this as the MCAI), to address an unsafe condition on Rotax 912 A, 912
F, 912 S and 912 iSc Sport (series) engines, all models, all serial
numbers; and Rotax 914 F (series) engines, all models, all serial
numbers. The MCAI states that the manufacturer reported an occurrence
of surface abnormalities on certain propeller shafts. Further
investigation by the manufacturer revealed that this abnormality was
caused by a deviation in the machining process. The manufacturer
determined on which engines the affected propeller shafts were
initially installed and that several of the affected propeller shafts
were delivered as spare parts. The manufacturer published service
information that identifies the affected propeller shafts and specifies
instructions for inspection and replacement of the propeller shaft.
This condition, if not addressed, could lead to increased wear of the
propeller shaft bearings, which could lead to failure of the propeller
shaft bearings, propeller shaft, and engine. This could result in
engine in-flight shutdown, and (for a single-engine airplane)
consequent emergency landing or loss of control of the airplane.
You may examine the MCAI in the AD docket at regulations.gov under
Docket No. FAA-2023-1809.
Related Service Information Under 1 CFR Part 51
The FAA reviewed Rotax Service Bulletin (SB) SB-912-078/SB-914-059/
SB-912 i-014, dated July 25, 2023 (published as a single document).
This service information identifies the serial numbers of the affected
engines and spare parts and specifies procedures for inspecting the
magnetic plug and replacing the propeller shaft with a part eligible
The FAA also reviewed Rotax SB SB-912-078UL/SB-914-059UL/SB-912 i-
014iS, dated July 25, 2023 (published as a single document). This
service information identifies the serial numbers of the affected
engines and spare parts.
These documents are distinct since they apply to different engine
models. 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.
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 and service information referenced above. The FAA is issuing
this AD after determining that the unsafe condition described
previously is likely to exist or develop on other products of the same
This AD requires initial and repetitive inspections of the magnetic
plug for the accumulation of metal chips to assess the condition of the
propeller gearbox for wear of the propeller shaft bearings and removal
of the affected propeller shaft from service and replacing it with a
part eligible for installation as a terminating action either
immediately or at a certain time depending on inspection findings. This
AD also prohibits the installation of the affected propeller shaft on
Differences Between This AD and the MCAI
The MCAI applies to all Rotax 912 A, 912 F, 912 S and 912 iSc Sport
(series) engines, all models, all serial numbers; and Rotax 914 F
(series) engines, all models, all serial numbers. Rotax Model
912 A, 912 A2, and 912 A3 engines are not type certificated in the
United States but are part of the type design for certain aircraft.
This AD applies to all Rotax Model 912 F2, 912 F3, 912 F4, 912 iSc2
Sport, 912 iSc3 Sport, 912 S2, 912 S3, 912 S4, 914 F2, 914 F3, and 914
F4 engines; and Model 912 A, 912 A2, and 912 A3 engines included as
part of the type design for Aeromot-Ind[uacute]stria Mec[acirc]nico-
Metal[uacute]rgica Ltda Model AMT-200 (Super Ximango); Diamond Aircraft
Industries Model HK 36 R ``SUPER DIMONA''; Diamond Aircraft Industries
GmbH Models HK 36 TC and HK 36 TS; Diamond Aircraft Industries Inc.
Model DA20-A1; HOAC-Austria Model DV 20 KATANA; Magnaghi Aeronautica
S.p.A Model Sky Arrow 650 TC; and SCHEIBE-Flugzeugbau GmbH Model SF 25C
aircraft, as applicable.
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 forgoing notice and comment prior to adoption of this rule
because the presence of material anomalies on the propeller shaft could
lead to wear of the propeller shaft bearings, which could lead to
failure of the propeller shaft bearings, propeller shaft, and engine,
which could result in engine in-flight shutdown, and (for a single-
engine airplane) consequent emergency landing or loss of control of the
airplane. Since this condition happens rapidly and without warning, the
initial inspection must be done before further flight with repetitive
inspections done every 10 flight hours (FHs) with terminating
replacement before further flight if wear of the propeller shaft
bearings is found or 50 FHs if no wear is found. These compliance times
are shorter than the time necessary for the public to comment and for
publication of the final rule.
Accordingly, notice and opportunity for prior public comment are
impracticable and contrary to the public interest pursuant to 5 U.S.C.
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
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 prior notice and
comment, RFA analysis is not required.
Costs of Compliance
The FAA estimates that this AD affects 287 engines installed on
aircraft of U.S. registry.
The FAA estimates the following costs to comply with this AD:
||1 work-hour x $85 per hour =
|Replace propeller shaft
||3 work-hours x $85 per hour =
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