[Federal Register Volume 88, Number 112 (Monday, June 12, 2023)]
[Rules and Regulations]
[Pages 37975-37985]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2023-12417]



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  Federal Register / Vol. 88 , No. 112 / Monday, June 12, 2023 / Rules 
and Regulations  

[[Page 37975]]



DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2022-0891; Project Identifier AD-2022-00585-A,E,R; 
Amendment 39-22432; AD 2023-09-09]
RIN 2120-AA64


Airworthiness Directives; Various Airplanes, Helicopters, and 
Engines

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule.

-----------------------------------------------------------------------

SUMMARY: The FAA is adopting a new airworthiness directive (AD) for 
turbocharged, reciprocating engine-powered airplanes and helicopters 
and turbocharged, reciprocating engines with a certain v-band coupling 
installed. This AD was prompted by multiple failures of spot-welded, 
multi-segment v-band couplings at the tailpipe to the turbocharger 
exhaust housing flange (also referred to as ``spot-welded, multi-
segment exhaust tailpipe v-band coupling''). This AD establishes a life 
limit for the spot-welded, multi-segment exhaust tailpipe v-band 
coupling and requires repetitively inspecting the spot-welded, multi-
segment exhaust tailpipe v-band coupling. The FAA is issuing this AD to 
address the unsafe condition on these products.

DATES: This AD is effective July 17, 2023.

ADDRESSES: AD Docket: You may examine the AD docket at regulations.gov 
by searching for and locating Docket No. FAA-2022-0891; 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 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.

FOR FURTHER INFORMATION CONTACT: Thomas Teplik, Aviation Safety 
Engineer, Central Certification Branch, FAA, 1801 S Airport Road, 
Wichita, KS 67209; phone: (316) 946-4196; email: [email protected] 
or [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 turbocharged, 
reciprocating engine-powered airplanes and helicopters and 
turbocharged, reciprocating engines with a certain v-band coupling 
installed. The NPRM published in the Federal Register on July 27, 2022 
(87 FR 45036). The NPRM was prompted by multiple failures of spot-
welded, multi-segment v-band couplings at the tailpipe to the 
turbocharger exhaust housing flange. In the NPRM, the FAA proposed to 
establish a life limit for the spot-welded, multi-segment exhaust 
tailpipe v-band coupling and require repetitively inspecting the spot-
welded, multi-segment exhaust tailpipe v-band coupling.
    Since the mid-1970s, failures of v-band couplings that attach the 
exhaust tailpipe to the turbocharger exhaust outlet have resulted in a 
significant number of incidents and accidents (fatal and non-fatal) on 
both airplanes and helicopters. Since 1974, National Transportation 
Safety Board (NTSB) accident and incident investigations have led to 
the issuance of 7 NTSB Safety Recommendations concerning exhaust 
systems and/or exhaust v-band couplings; 20 FAA ADs to address the 
unsafe condition with exhaust systems and/or exhaust v-band couplings; 
and 10 FAA Special Airworthiness Information Bulletins (SAIBs). 
Industry has also taken action to raise awareness of the concerns 
associated with v-band coupling failures.

         NTSB Safety Recommendations Affecting V-Band Couplings
------------------------------------------------------------------------
  NTSB safety recommendation       Description           Make/model
------------------------------------------------------------------------
A-90-166......................  Exhaust system...  Piper PA-32RT-300T,
                                                    PA-32R-301T.
A-90-165......................  Exhaust system...  Piper PA-32RT-300T,
                                                    PA-32R-301T.
A-90-164......................  Exhaust system...  Piper PA-32RT-300T,
                                                    PA-32R-301T.
A-88-151......................  Exhaust system...  Piper PA-32RT-300T.
A-88-150......................  Exhaust system...  Piper PA-32RT-300T.
A-88-147......................  Exhaust system...  Piper PA-32RT-300T.
A-74-099......................  V-band engine      Textron (Cessna)
                                 exhaust clamp      turbocharged 300/400
                                 failures.          series.
------------------------------------------------------------------------

    You may examine these NTSB Safety Recommendations in the AD docket 
at regulations.gov by searching for and locating Docket No. FAA-2022-
0891.

[[Page 37976]]



                         ADs on V-Band Couplings
------------------------------------------------------------------------
                 AD                               Make/model
------------------------------------------------------------------------
AD 2018-06-11, Amendment 39-19231    Textron Aviation Inc. Model A36TC
 (83 FR 13383, March 29, 2018).       and B36TC airplanes, all serial
                                      numbers, equipped with a
                                      turbocharged engine; Textron
                                      Aviation Inc. Model S35, V35,
                                      V35A, and V35B airplanes, all
                                      serial numbers, equipped with the
                                      Continental TSIO-520-D engine with
                                      AiResearch turbocharger during
                                      manufacture; and Textron Aviation
                                      Inc. Model S35, V35, V35A, and
                                      V35B airplanes, all serial
                                      numbers, equipped with Standard
                                      Aero Supplemental Type Certificate
                                      (STC) SA1035WE.
AD 2014-23-03, Amendment 39-18019    Piper Aircraft, Inc. Model PA-31P
 (79 FR 67340, November 13, 2014).    airplanes, serial numbers 31P-1
                                      through 31P-80 and 31P-7300110
                                      through 31P-7730012.
AD 2013-10-04, Amendment 39-17457    Piper Aircraft, Inc. Model PA-31,
 (78 FR 35110, June 12, 2013;         PA-31-325, and PA-31-350
 corrected September 5, 2013 (78 FR   airplanes, all serial numbers.
 54561)).
AD 2010-13-07, Amendment 39-16338    Piper Aircraft, Inc. Model PA-32R-
 (75 FR 35619, June 23, 2010;         301T airplanes, serial numbers
 corrected July 26, 2010 (75 FR       3257001 through 3257311; and Model
 43397)).                             PA-46-350P airplanes, serial
                                      numbers 4622001 through 4622200
                                      and 4636001 through 4636341.
AD 2004-23-17, Amendment 39-13872    Mooney Airplane Company Inc.
 (69 FR 67809, November 22, 2004).    (currently Mooney International
                                      Corporation) Model M20M airplanes,
                                      serial numbers 27-0001 through 27-
                                      0321.
AD 2001-08-08, Amendment 39-12185    Raytheon Aircraft Company
 (66 FR 20192, April 20, 2001).       (previously The Beech Aircraft
                                      Corporation; currently Textron
                                      Aviation Inc.) Model 35-C33A,
                                      E33A, E33C, F33A, F33C, S35, V35,
                                      V35A, V35B, 36, and A36 airplanes,
                                      all serial numbers, with Tornado
                                      Alley Turbo, Inc. STC SA5223NM and
                                      STC SE5222NM incorporated and with
                                      a Teledyne Continental engine
                                      equipped with a turbonormalizing
                                      system.
AD 2000-11-04, Amendment 39-11752    Commander Aircraft Company Model
 (65 FR 34941, June 1, 2000).         114TC airplanes, serial numbers
                                      20001 through 20027.
AD 2000-01-16, Amendment 39-11514    Cessna Aircraft Company (currently
 (65 FR 2844, January 19, 2000).      Textron Aviation Inc.) Model
                                      T310P, T310Q, T310R, 320, 320A,
                                      320B, 320C, 320D, 320E, 320F, 320-
                                      1, 335, 340, 340A, 321 (Navy OE-
                                      2), 401, 401A, 401B, 402, 402A,
                                      402B, 402C, 404, 411, 411A, 414,
                                      414A, 421, 421A, 421B, and 421C
                                      airplanes, all serial numbers.
AD 91-21-01 R1, Amendment 39-9470    Textron Lycoming Model TIO-540-S1AD
 (61 FR 29003, June 7, 1996;          reciprocating engines installed
 corrected September 6, 1996 (61 FR   on, but not limited to, Piper
 47051)).                             Aircraft, Inc. PA-32 series
                                      airplanes.
AD 81-23-03 R2, Amendment 39-4491    Cessna (currently Textron Aviation
 (47 FR 51101, November 12, 1982).    Inc.) Model P210N airplanes,
                                      serial numbers P21000001 through
                                      P21000811.
------------------------------------------------------------------------

    These ADs require v-band coupling replacements (life limit) and/or 
repetitive inspections, or changing the type design of the v-band 
coupling. This AD does not apply to airplanes that have complied with 
one of these ADs. You may examine these ADs in the AD docket at 
regulations.gov by searching for and locating Docket No. FAA-2022-0891.

                        SAIBs on V-Band Couplings
------------------------------------------------------------------------
           SAIB                               Subject
------------------------------------------------------------------------
CE-18-21.................  Exhaust Turbochargers; Announce the
                            availability of the ``Best Practices Guide
                            for Maintaining Exhaust System Turbocharger
                            to Tailpipe V-band Couplings/Clamps.''
CE-18-07.................  Exhaust Turbocharger; V-band Couplings Used
                            in Engine Exhaust Systems on Turbocharged
                            Reciprocating Engine Powered Aircraft.
CE-13-45.................  Engine Exhaust; Tailpipe V-band Couplings
                            [for turbocharged, reciprocating engine-
                            powered airplanes].
CE-13-07R1...............  Engine Exhaust; Tailpipe V-band Couplings
                            [for Cessna Aircraft Company (currently
                            Textron Aviation Inc.) Model T206H
                            airplanes].
CE-13-07.................  Engine Exhaust; Tailpipe V-band Couplings
                            [for Cessna Aircraft Company (currently
                            Textron Aviation Inc.) Model T206H
                            airplanes].
CE-10-33R1...............  Engine Exhaust [for reciprocating engine-
                            powered airplanes].
CE-10-33.................  Engine Exhaust [for reciprocating engine-
                            powered airplanes].
CE-09-11.................  Turbocharged Engines [for turbocharged engine-
                            powered airplanes].
CE-05-13.................  Alternative method of compliance (AMOC) to AD
                            91-03-15, Amendment 39-6870 (56 FR 3025,
                            January 28, 1991) for Mooney Aircraft
                            Corporation Model M20M airplanes.
CE-04-22.................  Exhaust System Components for reciprocating
                            engine-powered airplanes.
CE-03-46.................  Mooney Model M20M airplanes with turbocharged
                            engines using V-band clamps.
------------------------------------------------------------------------

    You may examine these SAIBs in the AD docket at regulations.gov by 
searching for and locating Docket No. FAA-2022-0891.
    In spite of these efforts, failures continue to occur and the 
number of significant safety events continues to increase. As a result, 
the General Aviation Joint Steering Committee (GA-JSC), which is 
comprised of both the FAA and industry, developed a working group to 
study v-band coupling failures

[[Page 37977]]

associated with turbocharged reciprocating engine-powered aircraft and 
develop recommended corrective actions. This v-band coupling working 
group was comprised of aviation industry manufacturers, type/user 
groups, and government entities. The working group was tasked to 
examine the turbocharger to tailpipe interface and develop 
recommendations to enhance the safety of the fleet.
    The working group recommended mandatory corrective actions that are 
tailored to each specific coupling type (spot-welded, riveted, or 
single piece), thereby minimizing the impact to owner/operators. The 
working group recommended a mandatory coupling replacement time (life 
limit) and annual inspection. The working group also recommended non-
mandatory actions to aid and educate maintenance personnel in 
appropriate v-band coupling removal, installation, and inspection 
practices. Finally, the working group recommended actions for new 
designs, which incorporate lessons learned from review of the in-
service fleet. For new designs incorporating a v-band coupling 
immediately downstream of the turbocharger exhaust discharge, the 
working group recommended that a replacement interval (500 hours for 
spot-welded and 2,000 hours for riveted and single-piece) be 
incorporated in the Airworthiness Limitations sections of the 
maintenance manual.
    In January 2018, the working group published a final report titled 
``Exhaust System Turbocharger to Tailpipe V-band Coupling/Clamp Working 
Group Final Report'' (final report). Appendix B of the final report 
contains the Best Practices Guide. The final report may be found in the 
AD docket at regulations.gov by searching for and locating Docket No. 
FAA-2022-0891.
    The final report concluded that the common denominator in the 
incidents and accidents reviewed is the spot-welded, multi-segment 
exhaust tailpipe v-band coupling (see Figure A). These couplings come 
in either two or three segment varieties. The segments are the number 
of v-retainer segments, which are attached to the outer band via spot 
welds. Although multi-segment exhaust tailpipe couplings can also be 
riveted, the riveted couplings do not create an unsafe condition.
[GRAPHIC] [TIFF OMITTED] TR12JN23.076

    The majority of the events studied by the working group indicated 
fatigue failure of spot-welded, multi-segment exhaust tailpipe v-band 
couplings as a result of stress corrosion cracking that originated at 
or near a spot weld. This is the same unsafe condition identified in 
the other v-band coupling AD actions previously referenced. The data 
studied by the working group contained evidence of pre-existing 
cracking of the couplings, known embrittlement at the

[[Page 37978]]

spot weld locations simply due to that manufacturing method, and outer 
band cupping on the multi-segment couplings (which is the result of 
age, over-use, and potential over-torqueing). The working group also 
found that many of the couplings had safety wire across the bolt end. 
The safety wire could be helpful if there was a bolt or nut failure 
(extremely rare events) or the nut was missing. However, the safety 
wire was of no value when the failure was transverse band cracking and 
total separation at the spot weld. The data studied by the working 
group indicated many accidents were due to v-band couplings that were 
of the multi-segment, spot-welded design, when used in a specific 
location (the tailpipe to the turbocharger exhaust housing flange on 
turbocharged reciprocating engine-powered aircraft).
    After the working group published the final report, the FAA issued 
SAIB CE-18-21, dated July 13, 2018. This SAIB announced the 
availability of the Best Practices Guide from the final report and 
recommended the public apply the best practices in the maintenance of 
turbocharged reciprocating engine powered aircraft. The FAA also 
assessed the recommendations contained in the final report and 
determined an unsafe condition exists in turbocharged reciprocating 
engine-powered aircraft with a spot-welded, multi-segment v-band 
coupling installed. Because these v-band couplings are widely used by 
many design approval holders on various models (engines and aircraft), 
several Aircraft Certification Office Branches were involved in the 
decision to propose a single AD. The FAA also determined that the 
corrective actions recommended in the final report were appropriate to 
address this unsafe condition.
    This condition, if not addressed, could lead to failure of the 
spot-welded, multi-segment exhaust tailpipe v-band coupling, leading to 
detachment of the exhaust tailpipe from the turbocharger and allowing 
high-temperature exhaust gases to enter the engine compartment. This 
could result in smoke in the cockpit, in-flight fire, and loss of 
control of the aircraft. The FAA is issuing this AD to address the 
unsafe condition on these products.

Discussion of Final Airworthiness Directive

Comments

    The FAA received comments from 32 commenters. The commenters were 
Aerostar Aircraft Corporation (Aerostar), European Union Aviation 
Safety Agency (EASA), NTSB, Vulcanair S.p.A, and 28 individuals. The 
NTSB and four individual commenters supported the AD without change. 
Aerostar, EASA, Vulcanair S.p.A., and 19 individual commenters do not 
necessarily oppose the NPRM but recommended certain changes. Five 
individual commenters oppose the proposal in its entirety. The 
following presents the comments received on the NPRM and the FAA's 
response to each comment.

A. Requests Regarding Withdrawing the NPRM

    Three individual commenters stated that current inspections are 
adequate and implied that they opposed the NPRM. Two other individual 
commenters stated that they opposed the NPRM. One of the commentors 
implied current inspections were sufficient and stated inspections of 
the v-band clamp at each oil change and on-condition replacement would 
be enough. One of the commenters who opposed the NPRM in its entirety 
also requested that information regarding exhaust couplers be added to 
FAA Advisory Circular (AC) 43.13-1B, Acceptable Methods, Techniques, 
and Practices--Aircraft Inspection and Repair, dated September 8, 1998 
(AC 43.13-1B). The FAA infers that these commenters are requesting that 
the NPRM be withdrawn.
    The FAA disagrees. This AD requires specific inspections that are 
not included in current inspections. The accident and incident failure 
data and existing ADs that are included in paragraphs (d) (1) through 
(10) of this AD demonstrate that a 500-hour time-in-service (TIS) life 
limit is appropriate for this type of multi-segment coupling. Regarding 
the request to revise AC 43.13-1B, that change is outside the scope of 
this AD and actions in an advisory circular provide guidance but are 
not mandatory.
    The FAA has not changed this AD as a result of these comments.

B. Requests Regarding Estimated Costs

1. Increase Work-Hour Rate
    Three individual commenters requested that the FAA increase the 
cost per work-hour specified in the NPRM. These commenters stated that 
$85 per work-hour is too low and does not reflect the true rate charged 
by their local maintenance facilities, which ranges from $100 to $140 
per work-hour. One of these commenters also reported that the estimated 
records review rate of $42.50 was not supported by industry practice 
and should be increased.
    The FAA disagrees. The FAA Office of Aviation Policy and Plans 
provides the labor rate of $85 per work-hour used when estimating the 
labor costs for complying with AD requirements. The estimate for the 
records review rate was based on \1/2\ hour at $85 per work-hour.
    The FAA has not changed this AD as a result of these comments.

2. Increase V-Band Coupling Removal and Replacement Costs

    Two individual commenters requested changes regarding the estimated 
costs in the NPRM for removal and replacement of v-band couplings. One 
of those commenters stated that there could be a discrepancy in the 
estimated costs per owner/operator. This commenter stated that the 
estimated figures did not appear to be unduly expensive in the interest 
of preventing a potential in-flight fire. The FAA infers that this 
commenter is requesting a revision to the estimated costs for removal 
and replacement of a v-band coupling based on the requested review of 
the cost estimates.
    The other individual commenter encouraged the FAA to increase the 
estimated cost in the NPRM for replacement of a v-band coupling and 
provided a cost of over $700 for the Piper Model PA-28R-201 airplane v-
band coupling. The FAA infers that the commenter is referring to the 
estimated parts cost of $400 for a single-engine aircraft.
    The FAA acknowledges that there may be discrepancies in the 
estimated costs among owners/operators for removing and replacing a v-
band coupling. The FAA's estimated number of work-hours were based on 
the actions required in AD 2018-06-11 and the parts costs were based on 
current pricing. Additional labor and parts costs were added for twin-
engine aircraft. In the NPRM, the FAA estimated costs in single-engine 
and twin-engine aircraft. The FAA disagrees that the cost of the v-band 
coupling needs to be increased. The estimated v-band coupling cost of 
$400 for a single-engine aircraft was based on a sampling of a range of 
parts costs for different aircraft. The FAA determined that $400 was an 
accurate parts cost for a single-engine aircraft.
    The FAA has not changed this AD as a result of these comments.

C. Requests Regarding Life Limit

1. Clarification of Mitigation for Installation of a V-Band Coupling 
That Exceeds 500-Hours TIS
    EASA suggested that there should be a mitigation of risk in place 
if a v-band coupling having 500 or more hours TIS

[[Page 37979]]

as of the effective date of the final rule is installed on an aircraft. 
EASA noted that paragraph (l)(1) of the proposed AD would allow the 
installation of a used v-band coupling of any age (i.e., more than 500 
hours TIS) within the first two years after the effective date of the 
final rule. EASA asked if requiring the repetitive inspections 
specified in paragraph (i)(2) of the proposed AD would mitigate this 
risk or, alternatively, if there should be a prohibition of the 
installation of a v-band coupling that has accumulated 500 or more 
hours TIS as of the effective date of the final rule.
    The FAA does not agree. The FAA provides mitigation for the risk 
associated with installing a v-band coupling having 500 or more hours 
TIS by requiring inspections every 6 months or every 100 hours TIS, 
whichever occurs first, for two years after the effective date of this 
AD. The inspections and inspection criteria are the same for the v-band 
couplings regardless of the inspection time interval. Paragraph (i)(2) 
of this AD was provided to allow compliance with the requirements of 
this AD with regards to hardware availability.
2. Justification for 500-Hour TIS Life Limit
    An anonymous commenter requested justification for the v-band 
coupling 500-hour TIS life limit specified in the NPRM and stated that 
the 500-hour TIS life limit seemed low. In regards to the study of 
accident rates where failure of the v-band coupling was determined to 
be at fault, the commenter asked how many hours the v-band coupling had 
accumulated since its initial installation. The commenter also inquired 
about the failure rate of higher grade material v-band couplings and 
asked if higher grade v-band coupling material would have an effect on 
the failure rate.
    The FAA determined the 500-hour TIS v-band coupling replacement 
time is necessary to correct the unsafe condition. The FAA based this 
determination on past precedence of some of the existing ADs that are 
included in paragraphs (d)(1) through (10) of this AD. The v-band 
couplings addressed in this AD are of similar steel material. The FAA 
has an obligation to issue an AD to address an unsafe condition. This 
AD addresses the unsafe condition through repetitive inspections and 
replacements. The FAA would consider any future design improvements as 
an AMOC following the procedures outlined in paragraph (n) of this AD.
    The FAA has not changed this AD in regard to this comment.
3. Replacement of V-Band Coupling Solely Based on Hours TIS
    Two commenters did not agree with the replacement of the v-band 
coupling based solely on flight hours (v-band coupling hours TIS). One 
commenter asserted the inspections specified in the proposed AD were 
adequate to uncover defects that would require replacing a v-band 
coupling and stated if a v-band clamp continuously passes inspection, 
there is no reason to discard it based on TIS. The other commenter 
stated that v-band couplings on its helicopters are already inspected 
for cracking, and the surrounding area is inspected for signs of 
cracking or soot, as part of pre-flight inspections. This commenter 
also stated that Enstrom Helicopter Corporation issued Service 
Directive Bulletin 0122 (Enstrom SDB 0122) that addresses inspections 
for cracks.
    The FAA disagrees with removing the requirement in paragraph (i) of 
this AD to replace a v-band coupling before it accumulates 500 hours 
TIS and instead allowing on-condition replacement based upon inspection 
results. The accident/incident failure rate and existing ADs that are 
included in paragraphs (d)(1) through (10) of this AD demonstrate that 
a 500-hour TIS life limit is appropriate for this type of multi-segment 
v-band coupling. Regarding Enstrom SDB 0122, the FAA has not issued an 
AD that mandates using that service information.
    The FAA has not changed this AD in regard to these comments.

D. Requests Regarding V-Band Coupling Serialization

    Two individual commenters recommended serialization of the v-band 
coupling.
    One of those commenters stated it would be difficult to determine 
the total hours TIS unless these parts are serialized. The other 
commenter recommended serialization by vibro-etching the tailpipe v-
band coupling to differentiate it from v-band couplings in other 
locations of an aircraft.
    The FAA disagrees that determination of a v-band coupling's hours 
TIS cannot be done without serialization either by vibro-etching or 
other means. Existing ADs that are included in paragraphs (d)(1) 
through (10) of this AD, regarding a v-band coupling with life limits 
have not required serialization. Once the hours TIS of a v-band 
coupling is established, subsequent maintenance actions will be based 
on hours TIS.
    The FAA has not changed this AD in regard to these comments.

E. Requests Regarding V-Band Coupling: Type Design and Manufacturing

    One individual commenter stated that instead of being spot-welded, 
the rings (v-band couplings) should be solid state welded. This 
commenter researched spot-welded couplings that revealed if the heat 
and pressure on the metal prior to the spot-weld is not consistent, the 
spot-weld will fail. Another individual commenter stated that spot-
welds are good in tension and not in shear. The commenter further 
explained that as the v-band coupling is tightened, the spot-weld is in 
shear, and that adding dynamic loads reduces the spot-weld's life even 
further. This commenter suggested that a different type of attachment 
be used such as a braze joint or a laser weld.
    Regarding the type design changes, an individual commenter asked if 
the installation of a riveted clamp would terminate the 500-hour TIS 
replacement schedule. Another individual commenter recommended using 
the v-band coupling information in Navair Technical Manual 1-1A-8, 
``Engineering Manual Series Aircraft and Missile Repair, Structural 
Hardware,'' which is used by the military, and adding this information 
to AC 43.13-1B. Another individual commenter stated that additional 
information on v-band couplings can be found in military specifications 
MS27116C, ``Coupling, Clamp, Grooved, V Band 1.750 To 14.250 Flange OD 
(Minus 320 Deg. To Plus 1500 Deg. F),'' and MIL-DTL-27536C, ``Coupling, 
Clamp, Grooved, V-Band.'' A different individual commenter suggested 
that by allowing a small [tungsten inert gas] TIG weld on the edges of 
the clamp, the concern regarding the spot welds holding would be 
addressed. An additional individual commenter referenced an unspecified 
photo linked to the NPRM and said it was not representative of current 
v-band coupling design.
    An individual commenter stated that during manufacturing, the 
single spot-welds might be placed too close to the trunnions, thereby 
causing failure points. This commenter suggested using a total of four 
spot-welds instead of two spot-welds. The FAA infers that the commenter 
is requesting a change to the manufacturing of the v-band coupling.
    The FAA has determined that inspections, in combination with life 
limits, are sufficient to mitigate the risk. The FAA would consider any 
future design improvements as an AMOC request following the procedures 
outlined in paragraph (n) of this AD. Regarding the proposed revision 
to AC

[[Page 37980]]

43.13-1B, that change is outside the scope of this AD and actions in an 
advisory circular are recommendations, not mandatory.
    The FAA has not changed this AD in regard to these comments.

F. Request for Clarification Regarding the Number/Percentage of In-
Flight Smoke and/or Fire Events

    An individual commenter requested clarification regarding the 
number or percentage of in-flight smoke and/or fire events related to 
the NPRM.
    The FAA does not have data indicating the specific number or 
percentage of incidents/accidents in which the v-band coupling failure 
caused a smoke event or an in-flight fire. At least one fatal accident 
and two non-fatal accidents involving a v-band coupling failure had 
occurrences of a fire. Smoke or fire could occur due to a separation of 
the v-band coupling or loss of the tailpipe because of the hot exhaust 
gases impinging on surrounding surfaces. This information was included 
in the FAA's determination that an unsafe condition existed to justify 
issuing this AD.
    The FAA has not changed this AD as a result of this comment.

G. Requests Regarding Applicability

1. Remove Airplanes With STC SA4976NM Installed
    Aerostar explained that airplanes with STC SA4976NM installed have 
eliminated the v-band coupling at the tailpipe to turbocharger 
connections and are not affected by the unsafe condition described in 
the proposed AD. Aerostar stated that STC SA4976NM was approved as an 
AMOC for the repetitive inspections required by AD 90-01-02, Amendment 
39-6517, January 5, 1990 (issued as a priority letter), that required 
repetitive dismantling inspections of the exhaust tailpipe assembly at 
intervals not to exceed 50-hours TIS. The FAA infers that Aerostar 
requested a change to the Applicability in the proposed AD to remove 
airplanes with STC SA4976NM installed.
    The FAA agrees. The installation of STC SA4976NM on Aerostar Model 
PA-600, -601, -601P, -602P and -700P airplanes eliminates the v-band 
coupling at the tailpipe to turbocharger connection. Paragraph (d), 
Applicability, of this AD was revised to add STC SA4976NM to the list 
of airplanes excepted from the applicability.
2. Remove Vulcanair S.p.A Model P.68B From the Applicability
    Vulcanair requested that Vulcanair S.p.A Model P.68B airplanes be 
removed from the Applicability Table in paragraph (d) of the proposed 
AD. The commenter stated Vulcanair S.p.A Model P.68B airplanes are 
equipped with two normally aspirated reciprocating engines.
    The FAA agrees and revised Table 1 to paragraph (d) of this AD to 
remove Vulcanair S.p.A Model P.68B airplanes. FAA Type Certificate Data 
Sheet A31EU lists the Model P.68B airplane as equipped with two 
Lycoming IO-360-A1B or Lycoming IO-360-A1B6 engines, which are normally 
aspirated. If the airplane is modified after certification by an STC, 
parts manufacturer approval, or field approval, with a turbocharged 
reciprocating engine with a spot-welded, multi-segment v-band coupling 
installed at the tailpipe to turbocharger exhaust housing flange, this 
AD is applicable.
3. Add Textron Aviation Inc. Model T182 and TR182 Airplanes Equipped 
With Lycoming O-540-L3C5D Engines
    An individual commenter asked why Model T182 and TR182 airplanes 
equipped with Lycoming O-540-L3C5D engines were not included in the 
applicability of the proposed AD. The FAA infers that this commenter is 
requesting that these airplane and engine combinations be added to the 
applicability of the proposed AD.
    The FAA agrees that these airplane models are affected by the 
requirements of this AD but a change to this AD is not necessary 
because Table 1 to paragraph (d) of this AD already includes Model T182 
and TR182 airplanes.
    The FAA has not changed this AD in regard to this comment.
4. Add Mooney Model M20F Airplanes With Aftermarket Installation
    An individual commenter asked if Model M20F airplanes with an 
aftermarket RayJay normalizing turbocharger are included in the 
applicability of the proposed AD. The FAA infers that this commenter is 
requesting that the applicability of the proposed AD be revised to 
include these airplane models.
    The FAA disagrees with adding the Mooney Model M20F airplanes 
equipped with an aftermarket RayJay normalizing turbocharger to the 
applicability of this AD because the FAA could not determine the STC 
that was being referred to. However, based on the way the final rule is 
written with language of ``as installed, but not limited to the 
following aircraft'', this AD would still apply to all turbocharged, 
reciprocating engine-powered airplanes and helicopters and 
turbocharged, reciprocating engines with a spot-welded, multi-segment 
v-band coupling installed at the tailpipe to turbocharger exhaust 
housing flange, except for airplanes that are in compliance with an AD 
listed in paragraphs (d)(1) through (10) of this AD or have STC 
SA4976NM installed. These ADs are available in the AD docket at 
regulations.gov by searching for and locating Docket No. FAA-2022-0891. 
These v-band couplings are installed on, but not limited to, the 
products listed in Table 1 to paragraph (d) of this AD. This AD would 
apply regardless of whether the turbocharger is installed as part of 
the type certificate, or under an STC, parts manufacture approval, or 
field approval. Outside of type certification, it is the responsibility 
of the owner working with a licensed mechanic to determine if the 
configuration of the aircraft includes the spot-welded multi segment v-
band coupling installed at the tailpipe to the turbocharger exhaust 
housing.
    The FAA has not changed this AD in regard to this comment.
5. Add Turbine Helicopters With V-Band Clamps
    An individual commenter asked if the NPRM needed to address v-band 
couplings installed on turbine helicopters. The FAA infers that the 
commenter requested to add turbine helicopters to the applicability of 
the proposed AD.
    The FAA disagrees. The use of the v-band couplings on turbine 
helicopters is not addressed in this AD. This AD addresses the unsafe 
condition for spot-welded, multi-segment v-band coupling installed at 
the tailpipe to turbocharger exhaust housing flange for turbocharged, 
reciprocating engine-powered airplanes and helicopters and 
turbocharged, reciprocating engines. The vibratory environment for 
turbine engines on helicopters is different and as such is not part of 
the identified unsafe condition.
    The FAA has not changed this AD in regard to this comment.
6. No Justification for Mooney Model M20K Airplanes
    An individual commenter stated that there is not enough information 
to justify an AD for a Mooney Model M20K airplane. The commenter cited 
FAA SAIB CE-18-07, ``Exhaust Turbocharger; V-band Couplings Used in 
Exhaust Systems on Turbocharged Reciprocating Engine Powered 
Aircraft,'' dated December 14, 2017 (SAIB CE-18-07), which states the 
``concern [was] not considered an unsafe condition that would warrant 
AD

[[Page 37981]]

action.'' The commenter also stated that a review of the FAA's Aviation 
Safety Information Analysis and Sharing System and the NTSB's Accident 
Database could not find any serious incidents involving defective v-
band couplings on Mooney Model M20K airplanes. The commenter supported 
an inspection regime and includes it in the pre-flight check and does 
an unspecified inspection of the v-band coupling at each oil change 
when the turbo is easily accessible. The commenter explained that there 
is a difference between ``big block'' 520-550 cubic-inch engines and 
smaller 360 turbocharged engines, and that the NTSB safety 
recommendations referred to in the NPRM refer to the ``big block'' 
engines. The commenter also pointed out that all of the ADs specified 
in the proposed AD apply to larger displacement turbocharged 
reciprocating engines.
    The FAA disagrees that there is not enough justification to include 
Mooney Model M20K airplanes in the applicability of this AD. When SAIB 
CE-18-07 was issued, the FAA was still evaluating this issue and had 
not determined that there was an unsafe condition warranting AD action. 
The v-band couplings that are the subject of this AD are used on both 
larger and smaller engines, and the inspections proposed in the NPRM 
are not part of current inspection criteria. The accident/incident 
failure data and existing AD actions demonstrate that a 500-hour TIS 
life limit is appropriate for this type of multi-segment coupling and 
that an unsafe condition exists.
    The FAA has not changed this AD in regard to this comment.

H. Requests Regarding Inspections

1. Revise Paragraph (j) of the Proposed AD To Separate Compliance Times 
From Inspection Procedures
    EASA requested that paragraph (j) of the proposed AD, ``Inspections 
Without Removal of the V-Band Coupling,'' be separated into two 
paragraphs with one paragraph containing the requirement for an annual 
inspection with references to both an inspection with the v-band 
coupling removed and an inspection with the v-band coupling installed, 
and the other paragraph containing the inspection procedure. The 
commenter stated that having the inspection timeline and the inspection 
procedures in the same paragraph may cause confusion.
    The FAA agrees that having the inspection compliance times and 
inspection procedures in the same paragraph could cause confusion. The 
FAA added paragraph (j), ``V-band Coupling Inspections,'' in this AD to 
specify only the inspection compliance times and re-designated the 
subsequent paragraphs accordingly. Paragraph (i)(2) of this AD still 
provides an alternative to initially removing the v-band coupling from 
service by doing the inspections required by paragraphs (k)(1) through 
(7) or (l) of this AD.

2. Remove Paragraph (j) of the Proposed AD

    EASA requested that paragraph (j) of the proposed AD, ``Inspections 
Without Removal of the V-Band Coupling,'' be removed because it is not 
possible to do a thorough inspection with the v-band coupling 
installed.
    The FAA disagrees. The procedures that the FAA included for the 
inspection of an installed v-band coupling were tested and it was 
determined that these procedures are adequate to verify the condition 
of the v-band coupling. If any of the inspection criteria for an 
installed v-band coupling are not met, the v-band coupling is required 
to either be replaced or undergo additional inspections with the v-band 
coupling removed. These procedures have been used with success in 
existing ADs that are included in paragraphs (d)(1) through (10) of 
this AD.
    The FAA has not changed this AD in regard to this comment.

3. Request To Revise Paragraph (j)(3) of the Proposed AD

    An individual commenter requested that paragraph (j)(3) of the 
proposed AD be moved to paragraph (k) of the proposed AD. The commenter 
stated that it could not be determined if the v-segments are loose with 
respect to the outer band with the outer band T-bolt torqued to 
specification. The commenter requested this inspection be moved to 
paragraph (j) after the v-band coupling is removed.
    The FAA disagrees with moving this inspection from paragraph (j)(3) 
of the proposed AD to paragraph (k) of this AD. Looseness of the v-band 
coupling may occur if the coupling is not properly installed. Looseness 
of the outer band may occur if the outer band has separated from the v-
band retainer segment or if the spot weld attachment is in the process 
of failing or has failed. Therefore, this inspection must be done 
without removing the v-band coupling.
    The FAA has not changed this AD in regard to this comment.
4. Include a Non-Destructive Inspection
    An individual commenter requested the FAA consider adding a 
requirement for a non-destructive inspection (NDI). The commenter 
stated the clamps are constantly stressed even in the absence of heat 
cycling.
    The FAA disagrees with adding a requirement for an NDI to this AD. 
Due to the various v-band couplings, an NDI would have to be determined 
by the v-band coupling manufacturer and the FAA has determined that the 
visual inspections along with replacements will mitigate the unsafe 
condition. However, additional inspections are acceptable as long as 
they do not conflict with the visual inspection requirements, 
replacement, and life limit requirements of this AD.
    The FAA has not changed this AD in regard to this comment.

5. Insufficient Justification for Paragraph (j) of the Proposed AD

    An individual commenter believed that there is not enough data to 
justify an AD, specifically for paragraph (j) of the proposed AD 
regarding repetitive inspections of v-band couplings. The commenter 
cited multiple examples where root cause analysis was determined in 
other AD actions. The commenter stated that the FAA has not made a 
determination of what the root cause is for the proposed AD.
    The FAA disagrees that there is no root cause for this AD. The FAA 
issues an AD when an unsafe condition is found. The unsafe condition 
addressed by this AD is fatigue failure of spot-welded, multi-segment 
exhaust tailpipe v-band couplings as a result of stress corrosion 
cracking that originated at or near a spot weld. As stated in the 
Background, the data studied by the working group contained evidence of 
pre-existing cracking of the couplings, known embrittlement at the spot 
weld locations simply due to that manufacturing method, and outer band 
cupping on the multi-segment couplings (which is the result of age, 
over-use, and potential over-torqueing). These are the root causes of 
the unsafe condition. Current inspection procedures are inadequate to 
detect these cracks in a timely manner. Accordingly, the FAA is 
mandating inspection procedures and a life limit to protect the fleet. 
The life limit and inspections directly address the unsafe condition, 
have been used in previous ADs, and therefore are appropriate for this 
type of multi-segment coupling.
    The FAA has not changed this AD in regard to this comment.

I. Request To Use Generic Terms in Paragraph (k) of the Proposed AD

    EASA suggested that generic terms be used in paragraph (k)(1)(i) of 
the proposed AD, such as ``fine abrasive

[[Page 37982]]

cloth and mineral spirits'' instead of ``crocus cloth and mineral 
spirits or Stoddard solvent'' because the current terminology in the 
proposed AD might not be recognized outside of the United States.
    The FAA partially agrees. The term ``crocus cloth'' is a general 
term and not specific. The term ``Stoddard solvent'' refers to the 
original developer of the solvent. This AD already includes the term 
``mineral spirts.'' The FAA revised paragraph (l)(1)(i) of this AD to 
include ``crocus cloth or fine abrasive cloth and mineral spirits or 
Stoddard solvent.''

Conclusion

    The FAA reviewed the relevant data, considered any comments 
received, 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 changes described previously, 
this AD is adopted as proposed in the NPRM. None of the changes will 
increase the economic burden on any operator.

Costs of Compliance

    The FAA estimates that this AD affects up to 41,058 airplanes, 
helicopters, and engines (products of U.S. registry). The FAA has no 
way of determining the number of these products that could have an 
affected spot-welded, multi-segment v-band coupling installed. The 
FAA's estimated cost on U.S. operators reflects the maximum possible 
cost based on the 41,058 products of U.S. registry. Based on this, the 
FAA estimates the following costs to comply with this AD:
    The FAA estimates the following costs to comply with this AD:

                                                 Estimated Costs
----------------------------------------------------------------------------------------------------------------
                                                                                     Number
             Action                   Labor cost       Parts    Cost per product    of U.S.      Cost on U.S.
                                                        cost                        products       operators
----------------------------------------------------------------------------------------------------------------
Aircraft records review.........  0.5 work hour x         N/A  $42.50............     41,058  $1,744,965.
                                   $85 = $42.50.
Removal of the coupling from      2 work-hours x $85     $400  $570..............     31,248  $17,811,360.
 service and replacement (single-  per hour = $170.
 engine aircraft).
Removal of the couplings from     4 work-hours x $85      800  $1,140............      9,810  $11,183,400.
 service and replacement (twin-    per hour = $340.
 engine aircraft).
Inspection of the coupling        0.5 work-hour x         N/A  $42.50 per             31,248  $1,328,040 per
 without removal (single-engine    $85 per hour =               inspection cycle.              inspection cycle.
 aircraft).                        $42.50.
Inspection of the couplings       1 work-hour x $85       N/A  $85 per inspection      9,810  $833,850 per
 without removal (twin-engine      per hour = $85.              cycle.                         inspection cycle.
 aircraft).
----------------------------------------------------------------------------------------------------------------


                                               On-Condition Costs
----------------------------------------------------------------------------------------------------------------
                                                                                                     Cost per
                       Action                                 Labor cost            Parts cost        product
----------------------------------------------------------------------------------------------------------------
Inspection of the coupling, including removal and     1.5 work-hours x $85 per               N/A         $127.50
 reinstallation (single-engine aircraft).              hour = $127.50.
Inspection of the couplings, including removal and    3 work-hours x $85 per                 N/A             255
 reinstallation (twin-engine aircraft).                hour = $255.
----------------------------------------------------------------------------------------------------------------

    This AD provides operators the option of performing an inspection 
with the coupling removed from the aircraft instead of an inspection of 
the coupling without removing it from the aircraft. In some cases, an 
inspection with the coupling removed may be required.
    A coupling may need to be removed from service before it reaches 
its 500-hour TIS life limit if it does not meet all of the inspection 
criteria at each inspection. The FAA has no way of determining the 
number of products that may need to remove the coupling from service 
before reaching its 500-hour TIS life limit.

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:

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.

[[Page 37983]]

Sec.  39.13  [Amended]

0
2. The FAA amends Sec.  39.13 by adding the following new airworthiness 
directive:

2023-09-09 Various Airplanes, Helicopters, and Engines: Amendment 39 
22432; Docket No. FAA-2022-0891; Project Identifier AD-2022-00585-
A,E,R.

(a) Effective Date

    This airworthiness directive (AD) is effective July 17, 2023.

(b) Affected ADs

    None.

(c) Definitions

    (1) For purposes of this AD, a ``v-band coupling'' means a spot-
welded, multi-segment v-band coupling installed at the tailpipe to 
turbocharger exhaust housing flange.
    (2) For purposes of this AD, ``new'' means zero hours time-in-
service (TIS).

(d) Applicability

    This AD applies to all turbocharged, reciprocating engine-
powered airplanes and helicopters and turbocharged, reciprocating 
engines, certificated in any category, with a spot-welded, multi-
segment v-band coupling installed at the tailpipe to turbocharger 
exhaust housing flange, except for airplanes that are in compliance 
with an AD listed in paragraphs (d)(1) through (10) of this AD, or 
have the supplemental type certificate (STC) listed in paragraph 
(d)(11) of this AD installed. These v-band couplings are installed 
on, but not limited to, the products listed in Table 1 to paragraph 
(d) of this AD.
    (1) AD 2018-06-11, Amendment 39-19231 (83 FR 13383, March 29, 
2018).
    (2) AD 2014-23-03, Amendment 39-18019 (79 FR 67340, November 13, 
2014).
    (3) AD 2013-10-04, Amendment 39-17457 (78 FR 35110, June 12, 
2013; corrected September 5, 2013 (78 FR 54561)).
    (4) AD 2010-13-07, Amendment 39-16338 (75 FR 35619, June 23, 
2010; corrected July 26, 2010 (75 FR 43397)).
    (5) AD 2004-23-17, Amendment 39-13872 (69 FR 67809, November 22, 
2004).
    (6) AD 2001-08-08, Amendment 39-12185 (66 FR 20192, April 20, 
2001).
    (7) AD 2000-11-04, Amendment 39-11752 (65 FR 34941, June 1, 
2000).
    (8) AD 2000-01-16, Amendment 39-11514 (65 FR 2844, January 19, 
2000).
    (9) AD 91-21-01 R1, Amendment 39-9470 (61 FR 29003, June 7, 
1996; corrected September 6, 1996 (61 FR 47051)).
    (10) AD 81-23-03 R2, Amendment 39-4491 (47 FR 51101, November 
12, 1982).
    (11) STC Number SA4976NM for Type Certificate Number: A17WE, 
Make: Aerostar, Model: PA-60-600, -601, -601P, -602P, and -700P.

Table 1 to Paragraph (d)--Applicability Includes, But Is Not Limited to,
   the Following Airplanes, Helicopters, and Engines When Turbocharged
------------------------------------------------------------------------
   Type certificate holder                       Model
------------------------------------------------------------------------
Aerostar Aircraft Corporation  PA-60-600 (Aerostar 600), PA-60-601
                                (Aerostar 601), PA-60-601P (Aerostar
                                601P), PA-60-602P (Aerostar 602P), and
                                PA-60-700P (Aerostar 700P).
B-N Group Ltd. (formerly       BN-2, BN-2A, BN-2A-6, BN-2A-8, and BN-2A-
 Pilatus Britten-Norman         9.
 Limited).
Cirrus Design Corporation....  SR22, SR22T.
Commander Aircraft             112TC, 112TCA, and 114TC.
 Corporation (formerly CPAC,
 Inc.; Commander Aircraft
 Company; Gulfstream
 Aerospace Corporation;
 Gulfstream American
 Corporation; and Rockwell
 International, Commander
 Aircraft Division).
Continental Aerospace          LTSIO-360-E, LTSIO-360-EB, LTSIO-360-KB,
 Technologies, Inc. (formerly   LTSIO-360-RB; TSIO-360-E, TSIO-360-EB,
 Continental Motors, Inc.,      TSIO-360-F, TSIO-360-FB, TSIO-360-KB,
 and Teledyne Continental       TSIO-360-LB, TSIO-360-MB, TSIO-360-RB,
 Motors).                       TSIO-360-SB; TSIO-520-BE, TSIO-520-L,
                                TSIO-520-LB, TSIO-520-T, TSIO-520-WB;
                                TSIO-550-A, TSIO-550-B, TSIO-550-C, TSIO-
                                550-E, TSIO-550-G, TSIO-550-J, TSIO-550-
                                K, TSIO-550-N; TSIOF-550-D, TSIOF-550-J,
                                IO-520-B, IO-520-BA, IO-520-BB, IO-520-
                                D, IO-550-B, IO-550-E, and IO-550-N.
Costruzioni Aeronautiche       P2012 Traveller.
 Tecnam S.P.A.
Daher Aerospace (formerly      TB 21.
 SOCATA and SOCATA--Groupe
 AEROSPATIALE).
Diamond Aircraft Industries    DA 40.
 Inc. (formerly Diamond
 Aircraft Industries GmbH).
The Enstrom Helicopter         F-28C, F-28C-2, F-28C-2R, F-28F, F-28F-R,
 Corporation.                   280C, 280F, and 280FX.
Helio Aircraft LLC...........  500.
Helio Alaska, Inc............  H-295 (USAF U-10D) and H-395 (USAF L-28A
                                or U-10B).
The King's Engineering         4500-300 and 4500-300 Series II.
 Fellowship (formerly Evangel-
 Air).
Lycoming Engines (formerly     IO-540-AA1A5, IO-540-AG1A5, IO-540-S1A5,
 Textron Lycoming).             TIO-540-AE2A, TIO-540-AH1A, TIO-540-
                                J2BD, TO-360-C1A6D, TO-360-E1A6D, LTO-
                                360-A1A6D, LTO-360-E1A6D, and LTIO-540-
                                J2BD.
Maule Aerospace Technology,    M-5-210TC.
 Inc. (formerly Maule
 Aircraft Corporation).
Merlyn Products, Inc.........  IO-540-MX1.
Mooney International           M20J, M20K, M20M, M20TN, and M20V.
 Corporation (formerly Mooney
 Aviation Company, Inc.;
 Mooney Airplane Company,
 Inc.; Mooney Aircraft
 Corporation; Aerostar
 Aircraft Corporation of
 Texas; and Mooney Aircraft
 Inc.).
Piper Aircraft, Inc.           PA-23, PA-23-160, PA-23-235, PA-23-250,
 (formerly The New Piper        PA-23-250 (Navy UO-1), PA-E23-250, PA-24-
 Aircraft, Inc.).               250, PA-24-260, PA-24-400, PA-28-201T,
                                PA-28R-201T, PA-28RT-201T, PA-30, PA-31,
                                PA-31-325, PA-31-350, PA-31P, PA-31P-
                                350, PA-32-260, PA-32R-300, PA-32RT-
                                300T, PA-32R-301(SP), PA-32-301T, PA-32R-
                                301T, PA-34-200, PA-34-200T, PA-34-220T,
                                PA-39, PA-44-180T, PA-46-310P, and PA-46-
                                350P.
Revo, Incorporated (formerly   Lake Model LA-4, Lake Model LA-4A, Lake
 Global Amphibians, LLC;        Model LA-4-200, and Lake Model 250.
 Consolidated Aeronautics,
 Inc.; Lake Aircraft
 Corporation; and Colonial
 Aircraft Company).
Scott's-Bell 47, Inc.          47G-3B, 47G-3B-1, 47G-3B-2, and 47G-3B-
 (formerly Bell Helicopter      2A.
 Textron Inc.).
Siam Hiller Holdings, Inc.     UH-12L and UH-12L4.
 (formerly Rogerson Hiller
 Corporation; Hiller
 Helicopters; Rogerson
 Aircraft Corporation; Hiller
 Aviation; Heli-Parts, Inc.;
 Fairchild Industries, Inc.;
 and Hiller Aircraft
 Corporation).
SST FLUGTECHNIK GmbH           EA 400.
 (formerly Extra
 Flugzeugproduktions-und
 Vertriebs-GmbH and Extra
 Flugzeugbau GmbH Flugplatz).

[[Page 37984]]

 
Textron Aviation Inc.          35-33, 35-A33, 35-B33, 35-C33, 35-C33A,
 (formerly Beechcraft           E33, E33A, E33C, F33, F33A, F33C, H35,
 Corporation, Hawker            J35, K35, M35, N35, P35, S35, V35, V35A,
 Beechcraft Corporation,        V35B, 36, A36, A36TC, B36TC, D55, E55,
 Raytheon Aircraft Company,     56TC (Turbo Baron), A56TC (Turbo Baron),
 and Beech Aircraft             58, G58, 60 (Duke), A60 (Duke), B60
 Corporation).                  (Duke), 95, 95-C55, B95, B95A, D95A, and
                                E95.
Textron Aviation Inc.          185, 185A, 185B, 185C, 185D, 185E, A185E,
 (formerly Cessna Aircraft      A185F, A188, A188A, A188B, A188C, T182,
 Company).                      T182T, TR182, T188C, 206, P206, P206A,
                                P206B, P206C, P206D, P206E, T206H,
                                TP206A, TP206B, TP206C, TP206D, TP206E,
                                TU206A, TU206B, TU206C, TU206D, TU206E,
                                TU206F, TU206G, U206, U206A, U206B,
                                U206C, U206D, U206E, U206F, U206G, T207,
                                T207A, 210, 210A, 210B, 210C, 210-5
                                (205), 210-5A (205A), P210N, T210G,
                                T210H, T210J, T210K, T210L, T210M,
                                T210N, T240, T303, 310, 310B, 310C,
                                310D, 310E (USAF U-3B), 310F, 310G,
                                310H, 310I, 310J, T310P, T310Q, T310R,
                                320, 320A, 320B, 320C, 320D, 320E, 320F,
                                320-1, 321, 335, 340, 340A, LC40-550FG,
                                LC41-550FG, LC42-550FG, FT337E, FT337F,
                                FT337GP, FT337HP, P337H, T337B, T337C,
                                T337D, T337E, T337F, T337G, T337H, T337H-
                                SP, 401, 401A, 401B, 402, 402A, 402B,
                                402C, 404, 411, 411A, 414, 414A, 421,
                                421A, 421B, 421C.
Triton Aerospace LLC           A500.
 (formerly Triton America
 LLC; AAI Acquisition, Inc.;
 and Adam Aircraft).
Twin Commander Aircraft LLC    500, 500A, 500B, 500S, 500U, 560A, 560E,
 (formerly Twin Commander       and 685.
 Aircraft Corporation;
 Gulfstream Aerospace
 Corporation; Gulfstream
 American Corporation;
 Rockwell-Standard &
 Associates; and Aero Design
 and Engineering Company,
 also known as Aero Commander
 Aircraft).
Vulcanair S.p.A. (formerly     P.68C-TC, and P.68TC ``Observer``.
 Partenavia Costruzioni
 Aeronautiche S.p.A.).
------------------------------------------------------------------------

(e) Subject

    Joint Aircraft System Component (JASC) Code 8100, Exhaust 
Turbine System (Recip).

(f) Unsafe Condition

    This AD was prompted by multiple failures of spot-welded, multi-
segment v-band couplings installed at the tailpipe to turbocharger 
exhaust housing flange. The FAA is issuing this AD to prevent 
failure of the spot-welded, multi-segment exhaust tailpipe v-band 
coupling. The unsafe condition, if not addressed, could lead to 
detachment of the exhaust tailpipe from the turbocharger and allow 
high-temperature exhaust gases to enter the engine compartment. This 
could result in smoke in the cockpit, in-flight fire, and loss of 
control of the aircraft.

(g) Compliance

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

(h) Review of the Maintenance Records

    Within 50 hours TIS after the effective date of this AD, review 
the aircraft maintenance records to determine the number of hours 
TIS accumulated on each v-band coupling.

(i) V-Band Coupling Life Limit

    (1) Within the compliance times specified in paragraph (i)(1)(i) 
or (ii) or (i)(2) of this AD, remove the v-band coupling from 
service and install a new v-band coupling. Apply correct torque as 
necessary to the v-band coupling nut.
    (i) If the v-band coupling has accumulated less than 500 hours 
TIS: Initially remove the v-band coupling from service before it 
accumulates 500 hours TIS or within 50 hours TIS after the effective 
date of this AD, whichever occurs later. Thereafter, remove the v-
band coupling from service before it accumulates 500 hours TIS.
    (ii) If the v-band coupling has accumulated 500 or more hours 
TIS or if the hours TIS of the v-band coupling cannot be determined: 
Initially remove the v-band coupling from service within 50 hours 
TIS after the effective date of this AD. Thereafter, remove the v-
band coupling from service before it accumulates 500 hours TIS.
    (2) As an alternative to initially removing the v-band coupling 
from service as required by paragraph (i)(1) of this AD, you may 
perform the inspections required by paragraphs (k)(1) through (7) or 
(l) of this AD. Do the initial inspections at the time the v-band 
coupling would have been removed from service and thereafter at 
intervals not to exceed 6 months or 100 hours TIS, whichever occurs 
first, for a period not to exceed 2 years after the effective date 
of this AD. If the v-band coupling fails to meet any inspection 
criteria in paragraphs (k)(1) through (7) or (l) of this AD, it must 
be removed from service before further flight. Removing the v-band 
coupling from service and installing a new v-band coupling does not 
terminate the requirement to do these repetitive inspections.
    Note 1 to paragraph (i): Instructions for installing a v-band 
coupling can be found in Appendix B: Best Practices Guide, paragraph 
3.1, of the ``Exhaust System Turbocharger to Tailpipe V-band 
Coupling/Clamp Working Group Final Report,'' dated January 2018.

(j) V-Band Coupling Inspections

    At the next annual inspection after the effective date of this 
AD or within the next 12 months after the effective date of this AD, 
whichever occurs first, and repetitively thereafter at intervals not 
to exceed 12 months, visually inspect the v-band coupling as 
required by paragraphs (k)(1) through (7) of this AD. Removing the 
v-band coupling from service and installing a new v-band coupling 
does not terminate the requirement to do these repetitive 
inspections.

(k) Inspections Without Removal of the V-Band Coupling

    (1) Inspect the v-band coupling and area around the v-band 
coupling for exhaust stains, sooting, and discoloration. If any of 
those conditions are found, remove the coupling and, instead of the 
inspections in paragraphs (k)(2) through (7) of this AD, do the 
inspections in paragraph (l) of this AD.
    (2) Inspect the v-band coupling outer band for cracks, paying 
particular attention to the spot weld areas. If there is a crack, 
before further flight, remove the v-band coupling from service and 
install a new v-band coupling.
    (3) Inspect the v-band coupling for looseness and for separation 
of the outer band from the v-retainer segments at all spot welds. If 
there is any looseness or separation of the outer band from any 
retainer segment, before further flight, remove the v-band coupling 
from service and install a new v-band coupling.
    (4) Inspect the v-band coupling outer band for cupping, bowing, 
and crowning as depicted in figure 1 to paragraph (l)(1)(iii) of 
this AD. If there is any cupping, bowing, or crowning, before 
further flight, remove the coupling and, instead of the inspections 
in paragraphs (k)(5) through (7) of this AD, do the inspections in 
paragraph (l) of this AD.
    (5) Inspect the area of the v-band coupling, including the outer 
band, opposite the t-bolt for damage and distortion. If there is any 
damage or distortion, before further flight, remove the v-band 
coupling from service and install a new v-band coupling.
    (6) Using a mirror, inspect the v-band coupling to determine 
whether there is a space between the two v-retainer coupling 
segments next to the t-bolt. If there is no space between the two v-
retainer coupling segments next to the t-bolt, before further 
flight, remove the v-band coupling from service and install a new v-
band coupling.
    (7) Determine whether the v-band coupling nut is properly 
torqued and apply correct torque as necessary.

[[Page 37985]]

(l) Inspections With the Spot-Welded, Multi-Segment Exhaust Tailpipe V-
Band Coupling Removed

    (1) Remove the v-band coupling and do the inspections in 
paragraphs (l)(1) and (2) of this AD if required by paragraph (k)(1) 
or (4) of this AD or as an alternative to the inspections required 
by paragraph (k) of this AD. Removing the v-band coupling from 
service and installing a new v-band coupling does not terminate the 
requirement to repeat the inspections in paragraph (k) or (l) of 
this AD.
    (i) Using crocus cloth or fine abrasive cloth and mineral 
spirits or Stoddard solvent, clean the outer band of the v-band 
coupling. Pay particular attention to the spot weld areas on the v-
band coupling. If there is corrosion that cannot be removed by 
cleaning or if there is pitting, before further flight, remove the 
v-band coupling from service and install a new v-band coupling.
    (ii) Using a 10X magnifying glass, visually inspect the outer 
band for cracks, paying particular attention to the spot weld areas. 
If there is a crack, before further flight, remove the v-band 
coupling from service and install a new v-band coupling.
    (iii) Visually inspect the flatness of the outer band using a 
straight edge. Lay the straight edge across the width of the outer 
band as depicted in figure 1 to paragraph (l)(1)(iii) of this AD. If 
the gap between the outer band and the straight edge exceeds 0.062 
inch, before further flight, remove the v-band coupling from service 
and install a new v-band coupling.
[GRAPHIC] [TIFF OMITTED] TR12JN23.077

    (iv) With the t-bolt in the 12 o'clock position, visually 
inspect the attachment of the outer band to the v-retainer coupling 
segments for gaps between the outer band and the v-retainer coupling 
segments from the 1 o'clock through 11 o'clock positions. If there 
are any gaps between the outer band and the v-retainer coupling 
segments, before further flight, remove the v-band coupling from 
service and install a new v-band coupling.
    Note 2 to paragraph (l)(1)(iv): You may use backlighting to see 
gaps.
    (v) Visually inspect the bend radii of the v-retainer coupling 
segments, throughout the length of the segment, as depicted in 
figure 1 to paragraph (l)(1)(iii) of this AD, for cracks. If there 
are any cracks, before further flight, remove the v-band coupling 
from service and install a new v-band coupling.
    (vi) Visually inspect the outer band opposite the t-bolt for 
damage (distortion, creases, bulging, or cracks) caused by excessive 
spreading of the coupling during installation or removal. If there 
is any damage, before further flight, remove the v-band coupling 
from service and install a new v-band coupling.
    (2) If the v-band coupling passes all of the inspections in 
paragraphs (l)(1)(i) through (vi) of this AD, it may be re-
installed.
    (i) Apply correct torque as necessary to the v-band coupling 
nut.
    (ii) Inspect the v-band coupling to determine whether there is 
space between the two v-retainer coupling segments next to the t-
bolt. If there is no space between the two v-retainer coupling 
segments next to the t-bolt, before further flight, remove the v-
band coupling from service and install a new v-band coupling.

(m) Installation Prohibitions

    (1) From the effective date of this AD until two years after the 
effective date of this AD, do not install a v-band coupling that has 
accumulated more than zero hours TIS on any turbocharged airplane, 
helicopter, or engine, unless it has passed all inspections required 
by paragraph (k) or (l) of this AD.
    (2) As of two years after the effective date of this AD, do not 
install a v-band coupling that has accumulated more than zero and 
less than 500 hours TIS on any turbocharged airplane, helicopter, or 
engine, unless it has passed all inspections required by paragraph 
(k) or (l) of this AD.
    (3) As of two years after the effective date of this AD, do not 
install a v-band coupling that has accumulated 500 or more hours TIS 
on any turbocharged airplane, helicopter, or engine.

(n) Alternative Methods of Compliance (AMOCs)

    (1) The Manager, Operational Safety 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 Operational Safety Branch, send it to 
the attention of Tom Teplik, add this AD number AD 2023-09-09 to the 
subject line, 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.

(o) Related Information

    (1) For more information about this AD, contact Thomas Teplik, 
Aviation Safety Engineer, Central Certification Branch, FAA, 1801 S 
Airport Road, Wichita, KS 67209; phone: (316) 946-4196; email: 
[email protected] or [email protected].
    (2) The ``Exhaust System Turbocharger to Tailpipe V-band 
Coupling/Clamp Working Group Final Report,'' dated January 2018, may 
be found in the AD docket at regulations.gov by searching for and 
locating Docket No. FAA-2022-0891.

(p) Material Incorporated by Reference

    None.

    Issued on May 9, 2023.
Gaetano A. Sciortino,
Acting Director, Compliance & Airworthiness Division, Aircraft 
Certification Service.
[FR Doc. 2023-12417 Filed 6-9-23; 8:45 am]
BILLING CODE 4910-13-P