DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2023-0172; Project Identifier AD-2023-00265-E;
Amendment 39-22355; AD 2023-04-08]
Airworthiness Directives; Continental Aerospace Technologies,
Inc. Reciprocating Engines
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Final rule; request for comments.
SUMMARY: The FAA is adopting a new airworthiness directive (AD)
certain Continental Aerospace Technologies, Inc. (Continental) GTSIO-
520-C, -D, -H, -K, -L, -M, -N, and -S; IO-360-A, -AB, -AF, -C, -CB, -D,
-DB, -E, -ES, -G, -GB, -H, -HB, -J, -JB, -K, and -KB; IO-470-D, -E, -G,
-H, -J, -K, -L, -M, -N, -P, -R, -S, -T, -U, -V, and -VO; IO-520-A, -B,
-BA, -BB, -C, -CB, -D, -E, -F, -J, -K, -L, -M, and -MB; IO-550-A, -B,
C, -D, -E, -F, -G, -L, -N, -P, and -R; LTSIO-360-E, -EB, -KB, and -RB;
LTSIO-520-AE; O-470-A, -B, -E, -G, -H, -J, -K, -L, -M, -N, -R, -S, -T,
and -U; TSIO-360-A, -AB, -B, -BB, -C, -CB, -D, -DB, -E, -EB, -G, -GB,
H, -HB, -JB, -KB, -LB, -MB, -RB, and -SB; TSIO-520-A, -AE, -AF, -B, -
BB, -BE, -C, -CE, -D, -DB, -E, -EB, -G, -H, -J, -JB, -K, -KB, -L, -LB,
-M, -NB, -P, -R, -T, -UB, -VB, and -WB; TSIO-550-A, -B, -C, -E, -G, -K,
and -N; TSIOF-550-K; and TSIOL-550-A, -B, and -C model reciprocating
engines. This AD was prompted by a report of a quality escape involving
improper installation of counterweight retaining rings in the engine
crankshaft counterweight groove during manufacture. This AD requires
inspection of the crankshaft assembly for proper installation of the
counterweight retaining rings in the counterweight groove, and
corrective actions if improper installation is found. The FAA is
issuing this AD to address the unsafe condition on these products.
DATES: This AD is effective February 23, 2023.
The Director of the Federal Register approved the incorporation by
reference of a certain publication listed in this AD as of February 23,
The FAA must receive comments on this AD by April 10, 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 by
searching for and locating Docket No. FAA-2023-0172; 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.
Material Incorporated by Reference:
For Continental service information identified in this
final rule, contact Continental Aerospace Technologies, Inc., 2039
South Broad Street, Mobile, AL 36615; phone: (251) 308-9100; email:
MSB23Support@continental.aero; website: continental.aero.
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 by searching for and locating Docket
FOR FURTHER INFORMATION CONTACT: Nicholas Reid, Aviation Safety
Engineer, Atlanta ACO Branch, FAA, 1701 Columbia Avenue, College Park,
GA 30337; phone: (404) 474-5650; email: firstname.lastname@example.org.
The FAA received a report of a quality escape involving improper
installation and inspection of counterweight retaining rings in the
engine crankshaft counterweight groove during manufacture. The FAA has
also received reports of two ground engine seizures and one in-flight
loss of engine oil pressure due to improper installation of the
counterweight retaining rings during manufacture. The counterweight
retaining rings are part of the engine crankshaft counterweight
assembly retention system. Loosening of a counterweight retaining ring
may result in the loss of retention of the counterweight. This
condition, if not addressed, could result in loss of engine oil
pressure, catastrophic engine damage, and possible engine seizure. The
FAA is issuing this AD to address the unsafe condition on these
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.
Related Service Information Under 1 CFR Part 51
The FAA reviewed Continental Mandatory Service Bulletin MSB23-01,
Revision A, dated February 16, 2023 (MSB23-01A). This service
information specifies procedures for inspection of the crankshaft
assembly for improper installation of the counterweight retaining rings
in the counterweight, and corrective actions if improper installation
is found. 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 accomplishing the actions specified in paragraph
III, Action Required, of MSB23-01A, except as discussed in ``Exception
to the Service Information.''
Differences Between This AD and the Service Information
The service information specifies compliance for engines with less
than 200 operating hours, while this AD
requires compliance for all affected engines, regardless of the
operating hours. The FAA has determined that this unsafe condition, of
improperly installed counterweight retaining rings, is likely to exist
on affected engines. While the manufacturer's service information
excludes engines accumulating 200 or more operating hours, the FAA has
not, as of yet, been provided with adequate data to support that
exclusion. In the event the FAA receives data to support the exclusion
of engines with more than 200 operating hours, or make other changes to
this AD, the FAA may consider further rulemaking.
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 manufacturer discovered an assembly error for the affected engines.
It is possible that one or more counterweight retaining rings were not
properly seated in the crankshaft counterweight groove of the engine.
This condition could allow the counterweight to depart from the
crankshaft during engine operation. Because of the urgency of the
unsafe condition, this AD requires inspection of any affected
crankshaft assembly before further flight. The manufacturing quality
escape has resulted in ground engine seizures and an in-flight loss of
engine oil pressure, which could lead to catastrophic engine damage,
engine seizure, and consequent loss of the aircraft. Due to the low
operational hours on the known crankshaft assembly failures, the short-
term risk to the fleet is such that expeditious action must be taken
and therefore this AD is effective upon publication. The FAA is issuing
this AD to address the unsafe condition on these products. As the
affected crankshaft assembly must be inspected before further flight
after the effective date of this AD, the compliance time for the
required actions is shorter than the time necessary to allow for public
comment and for the FAA to publish a final rule. 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 forego 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-2023-0172; Project Identifier AD-
2023-00265-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
Nicholas Reid, Aviation Safety Engineer, Atlanta ACO Branch, FAA, 1701
Columbia Avenue, College Park, GA 30337. 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 manufacturer has notified the FAA that 2,176 crankshaft
assemblies are subject to the unsafe condition. The FAA estimates that
of those 2,176 crankshaft assemblies, 1,632 are installed on aircraft
of U.S. registry. The FAA estimates that 544 engines will need to
remove one cylinder, 544 engines will need to remove two cylinders, and
544 engines will need to remove three cylinders for compliance with
The FAA estimates the following costs to comply with this AD:
||Cost per product
||Cost on U.S.
|Remove one cylinder
||10 work-hours x $85 per hour
|Remove two cylinders
||18 work-hours x $85 per hour
|Remove three cylinders
||22 work-hours x $85 per hour
|Inspect crankshaft counterweight
||0.75 work-hours x $85 per hour
|Reposition, repeat, or remove/install
||1.5 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