DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2023-0435; Project Identifier AD-2023-00384-E;
Amendment 39-22385; AD 2023-05-16]
Airworthiness Directives; Continental Aerospace Technologies,
Inc., Reciprocating Engines
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Final rule; request for comments.
SUMMARY: The FAA is superseding Airworthiness Directive (AD) 2023-04-08
which applied to 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. AD 2023-04-08 required
inspection of the crankshaft assembly for proper installation of the
counterweight retaining rings in the counterweight groove and,
depending on the results of the inspection, corrective actions if
improper installation was found. This AD continues to require
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. Since the FAA
issued AD 2023-04-08, operators notified the FAA, and Continental
confirmed, that certain affected model reciprocating engines not
included in the applicability of AD 2023-04-08 are also affected by the
unsafe condition. Additionally, the FAA determined the special flight
permit paragraph required revision. 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. The FAA is issuing this AD to address the unsafe condition
on these products.
DATES: This AD is effective March 15, 2023.
The Director of the Federal Register approved the incorporation by
reference of a certain publication listed in this AD as of February 23,
2023 (88 FR 11383, February 23, 2023).
The FAA must receive any comments on this AD by May 1, 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-2023-0435; 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: email@example.com.
The FAA issued AD 2023-04-08, Amendment 39-22355 (88 FR 11383,
February 23, 2023) (AD 2023-04-08), for 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.
AD 2023-04-08 required accomplishing the actions specified in paragraph
III, Action Required, of Continental Aerospace Technologies, Inc.
Mandatory Service Bulletin MSB23-01, Revision A, dated February 16,
2023 (MSB23-01A), except as discussed in ``Exception to the Service
Information.'' AD 2023-04-08 resulted from a report of a quality escape
involving improper installation and inspection of counterweight
retaining rings in the engine crankshaft counterweight groove during
manufacture. AD 2023-04-08 also resulted from 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. The FAA issued AD 2023-04-08 to prevent departure of
counterweight and retaining hardware from the crankshaft assembly,
which could result in loss of engine oil pressure, catastrophic engine
damage, engine seizure, and consequent loss of the aircraft.
Actions Since AD 2023-04-08 Was Issued
Since the FAA issued AD 2023-04-08, the FAA has determined, and
Continental has confirmed that IO-470-A, -C, -F, and -LO; TSIO-360-F;
and TSIO-360-FB model reciprocating engines are also affected by the
unsafe condition and should be added to the applicability.
Additionally, the FAA determined that the limitations in the special
flight permit paragraph, specifying no metal contamination in the oil
filter, did not account for trace metal particles that may be found in
newer engines due to break-in of the engine.
Accordingly, Continental IO-470-A, -C, -F, and -LO; TSIO-360-F; and
TSIO-360-FB model reciprocating engines are added to the applicability
paragraph of this AD. Also, the special flight permit paragraph of this
AD has been revised, removing the limitation of ``no metal
contamination.'' The FAA is issuing this AD to address the unsafe
condition on these products.
Discussion of Final Airworthiness Directive
Comments on AD 2023-04-08
The FAA received comments from seven individual commenters. The
following presents the comments received on AD 2023-04-08 and the FAA's
response to each comment.
Request To Add Engine Models to Applicability
Two individual commenters noted that there are engine models listed
in the appendices of MSB23-01A that are omitted from the applicability
of AD 2023-04-08.
The FAA agrees, and has revised the applicability paragraph of this
AD to include Continental IO-470-A, -C, -F, and -LO; TSIO-360-F; and
TSIO-360-FB model reciprocating engines.
Request To Include Part Listing and Serial Numbers in the AD
Two individual commenters requested that the list of affected parts
and production dates should be included in the AD. Another individual
commenter requested that the serial numbers of affected crankshafts and
applicable manufacture date range of the affected engines should be
included in the AD.
The FAA disagrees with the requests. MSB23-01A, which is
incorporated by reference into this AD, contains the list of affected
engines and crankshafts. Therefore, duplicating the appendix
information from the service information into the AD is unnecessary.
The FAA notes that paragraph (g)(2) of the required actions specifies
``crankshaft assembly that was repaired or installed on or after June
1, 2021.'' The FAA did not change this AD as a result of this comment.
Request To Correct Text in the Required Actions Paragraph
One individual commenter stated that AD 2023-04-08 has incorrect
language in the required actions, paragraph (g)(1), which reads; ``(1)
Crankshaft assembly having a crankshaft serial number listed in
Appendix 1 of MSB23-01A; or''. The commenter noted that Appendix 1 of
MSB23-01A lists engine assembly serial numbers with associated
installed crankshaft serial numbers.
The FAA disagrees that the language in paragraph (g)(1) is
incorrect. MSB23-01A contains the affected engine serial numbers and
crankshaft serial numbers, differentiated by engine model. The FAA did
not change this AD as a result of this comment.
Request To Review Labor Cost
Two individual commenters stated that the $85 labor rate in the
estimated costs section of the AD is outdated. One commenter noted that
the rate is well below the average shop rate for other trades, and
suggested that by endorsing this rate, the FAA may be attracting less
detail-oriented employees, thereby creating an unsafe condition.
The FAA disagrees. The FAA Office of Aviation Policy and Plans
provides the labor rate of $85 per work-hour for the FAA to use when
estimating the labor costs of complying with AD requirements. The FAA
did not change this AD as a result of this comment.
Request To Include Cost of Individual Parts
An individual commenter noted that costs of complete seal and
gasket kits for each cylinder (valve cover, induction, push rods x 4,
cylinder) are not included in the cost estimate in AD-2023-04-08.
The FAA acknowledges the commenter's concerns. The FAA recognizes
that in accomplishing the requirements of any AD, operators might incur
``incidental'' costs in addition to the ``direct'' costs that are
reflected in the cost analysis presented in the AD. However, the cost
analysis in ADs typically does not include incidental costs. No change
was made to this AD regarding this issue.
Request To Add Information on Cylinder Ring Seating
An individual commenter stated they have a factory new Continental
IO-470-N engine that is affected by this AD. The commenter stated their
new motor was run at the factory before being shipped to them, so ring
scoring had taken place. The commenter suggested that the AD might
serve the impacted population by pointing out that cylinder rings may
not seat. The commenter also expressed concern over the potential need
to install new counterweight retaining rings on their factory new
Continental IO-470-N engine.
The FAA disagrees with adding additional language to the AD
regarding cylinder ring seating. The AD requires inspection of the
counterweight retaining rings on affected engines using the referenced
service information. MSB23-01A Paragraph III, note to paragraph 2(c)
specifies that if counterweight retaining ring(s) are removed from the
counterweight, new retaining ring(s) are required for reassembly. The
FAA did not change this AD as a result of this comment.
Revision of Special Flight Permit Paragraph
The FAA revised the special flight permit paragraph of this AD by
modifying the requirement to inspect the engine oil filter pleats or
screen for evidence of metal contamination. The revised special flight
permit paragraph in this AD requires that the engine first undergoes,
or has undergone within the previous five flight hours, an oil change
and filter/screen replacement that was accomplished by an appropriately
rated mechanic or repair station, and any material found in the spent
oil and oil filter pleats or oil screen has been evaluated to assess
the engine's condition.
The FAA is issuing this AD because the agency 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 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 to make other changes to this AD, the
FAA may consider further rulemaking.
The service information excludes Continental IO-470-A, -C, -F, and
-LO; TSIO-360-F; and TSIO-360-FB model reciprocating engines from its
list of affected engine models, while this AD includes these engines in
the applicability paragraph.
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
because 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.
Since the FAA issued AD 2023-04-08, the FAA has determined, and
Continental has confirmed that Continental IO-470-A, -C, -F, and -LO;
TSIO-360-F; and TSIO-360-FB model reciprocating engines were
inadvertently left off of the list of affected engine models in MSB23-
01A. Due to this omission, Continental IO-470-A, -C, -F, and -LO; TSIO-
360-F; and TSIO-360-FB model reciprocating engines with affected
crankshafts were not captured by the applicability of AD 2023-04-08.
Because the urgency of the unsafe condition applies to these additional
model engines, this AD also requires inspection of the crankshaft
assemblies on these engines before further flight, in addition to the
population originally captured by AD 2023-04-08.
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
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 comment.
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-2023-0435 and Project Identifier
AD-2023-00384-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
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 FAA has revised the cost estimate of AD 2023-04-08 based on
updated information from the manufacturer. The model engines added to
the applicability of this superseding AD were accounted for in the cost
estimate of AD 2023-04-08, as that cost estimate was based on the list
of affected engines and crankshafts in the appendices of MSB23-01A, not
on the list of model engines in MSB23-01A.
The manufacturer has notified the FAA that 2,211 crankshaft
assemblies are subject to the unsafe condition. The FAA estimates that
of those 2,211 crankshaft assemblies, 1,659 are installed on aircraft
of U.S. registry. The FAA estimates that 553 engines will need to
remove one cylinder, 553 engines will need to remove two cylinders, and
553 engines will need to remove three cylinders for compliance with
The FAA estimates the following costs to comply with this AD:
|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:
a. Removing Airworthiness Directive 2023-04-08, Amendment 39-22355 (88
FR 11383, February 23, 2023); and
b. Adding the following new airworthiness directive: