[Federal Register Volume 87, Number 143 (Wednesday, July 27, 2022)]
[Proposed Rules]
[Pages 45036-45046]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2022-16139]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

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


Airworthiness Directives; Various Airplanes, Helicopters, and 
Engines

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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

SUMMARY: The FAA proposes to adopt 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 proposed 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 
proposed AD would 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. The FAA is proposing this AD to address the unsafe condition 
on these products.

DATES: The FAA must receive comments on this proposed AD by November 4, 
2022.

ADDRESSES: You may send comments, using the procedures found in 14 CFR 
11.43 and 11.45, by any of the following methods:
     Federal eRulemaking Portal: Go to www.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.

Examining the AD Docket

    You may examine the AD docket at www.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 NPRM, any comments 
received, and other information. The street address for Docket 
Operations is listed above.

FOR FURTHER INFORMATION CONTACT: Thomas Teplik, Aviation Safety 
Engineer, Wichita ACO Branch, FAA, 1801 S. Airport Road, Wichita, KS 
67209; phone: (316) 946-4196; email: [email protected] or [email protected].

SUPPLEMENTARY INFORMATION:

Comments Invited

    The FAA invites you to send any written relevant data, views, or 
arguments about this proposal. Send your comments to an address listed 
under ADDRESSES. Include ``Docket No. FAA-2022-0891; Project Identifier 
AD-2022-00585-A,E,R'' 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 proposal 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 
www.regulations.gov, including any personal information you provide. 
The agency will also post a report summarizing each substantive verbal 
contact received about this NPRM.

[[Page 45037]]

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 NPRM 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 NPRM, 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 NPRM. Submissions containing CBI should be sent Thomas 
Teplik, Aviation Safety Engineer, Wichita ACO Branch, FAA, 1801 S. 
Airport Road, Wichita, KS 67209. Any commentary that the FAA receives 
which is not specifically designated as CBI will be placed in the 
public docket for this rulemaking.

Background

    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 www.regulations.gov by searching for and locating Docket No. FAA-
2022-0891.

                         ADs on V-Band Couplings
------------------------------------------------------------------------
              AD                               Make/model
------------------------------------------------------------------------
AD 2018-06-11, Amendment 39-   Textron Aviation Inc. Model A36TC and
 19231 (83 FR 13383, March      B36TC airplanes, all serial numbers,
 29, 2018).                     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 StandardAero
                                Supplemental Type Certificate (STC)
                                SA1035WE.
AD 2014-23-03, Amendment 39-   Piper Aircraft, Inc. Model PA-31P
 18019 (79 FR 67340, November   airplanes, serial numbers 31P-1 through
 13, 2014).                     31P-80 and 31P-7300110 through 31P-
                                7730012.
AD 2013-10-04, Amendment 39-   Piper Aircraft, Inc. Model PA-31, PA-31-
 17457 (78 FR 35110, June 12,   325, and PA-31-350 airplanes, all serial
 2013; corrected September 5,   numbers.
 2013, 78 FR 54561).
AD 2010-13-07, Amendment 39-   Piper Aircraft, Inc. Model PA-32R-301T
 16338 (75 FR 35619, June 23,   airplanes, serial numbers 3257001
 2010; corrected July 26,       through 3257311; and Model PA-46-350P
 2010, 75 FR 43397).            airplanes, serial numbers 4622001
                                through 4622200 and 4636001 through
                                4636341.
AD 2004-23-17, Amendment 39-   Mooney Airplane Company Inc. (currently
 13872 (69 FR 67809, November   Mooney International Corporation) Model
 22, 2004).                     M20M airplanes, serial numbers 27-0001
                                through 27-0321.
AD 2001-08-08, Amendment 39-   Raytheon Aircraft Company (previously The
 12185 (66 FR 20192, April      Beech Aircraft Corporation; currently
 20, 2001).                     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-   Commander Aircraft Company Model 114TC
 11752 (65 FR 34941, June 1,    airplanes, serial numbers 20001 through
 2000).                         20027.
AD 2000-01-16, Amendment 39-   Cessna Aircraft Company (currently
 11514 (65 FR 2844, January     Textron Aviation Inc.) Model T310P,
 19, 2000).                     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-  Textron Lycoming Model TIO-540-S1AD
 9470 (61 FR 29003, June 7,     reciprocating engines installed on, but
 1996; corrected September 6,   not limited to, Piper Aircraft, Inc. PA-
 1996, 61 FR 47051).            32 series airplanes.
AD 81-23-03 R2, Amendment 39-  Cessna (currently Textron Aviation Inc.)
 4491 (47 FR 51101, November    Model P210N airplanes, serial numbers
 12, 1982).                     P21000001 through P21000811
------------------------------------------------------------------------


[[Page 45038]]

    These ADs require v-band coupling replacements (life limit) and/or 
repetitive inspections, or changing the type design of the v-band 
coupling. This proposed AD would not apply to airplanes that have 
complied with one of these ADs. You may examine these ADs in the AD 
docket at www.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 www.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 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 www.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.
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[GRAPHIC] [TIFF OMITTED] TP27JY22.001

BILLING CODE 4910-13-C
    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 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.

FAA's Determination

    The FAA is issuing this NPRM after determining that the unsafe 
condition described previously is likely to exist or develop on other 
products of the same type design.

[[Page 45040]]

Proposed AD Requirements in This NPRM

    This proposed AD would apply to all reciprocating turbocharged 
airplanes, helicopters, and reciprocating engines that have a spot-
welded, multi-segment v-band coupling installed at the tailpipe to the 
turbocharger exhaust housing flange. The proposed 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. The proposed AD would not apply to airplanes that have 
complied with certain ADs listed in paragraph (d) of the proposed AD.
    This proposed AD would require the following actions:
     Repetitively inspecting the spot-welded, multi-segment 
exhaust tailpipe v-band couplings annually, regardless of the hours 
time-in-service (TIS) accumulated on the v-band coupling; and
     Establishing a life limit for the spot-welded, multi-
segment exhaust tailpipe v-band couplings by removing them from service 
every 500 hours TIS.
    As an alternative for the first time the spot-welded, multi-segment 
exhaust tailpipe v-band coupling must be removed from service due to 
the 500 hour life limit, this proposed AD would allow doing the 
repetitive inspections every 6 months or 100 hours TIS, whichever 
occurs first, for a period of 2 years, as long as the v-band coupling 
continues to pass all of the inspections.
    Replacing a spot-welded, multi-segment exhaust tailpipe v-band 
coupling with a v-band of a different part number or type (riveted or 
single piece) would not be permitted, unless previously FAA-approved as 
part of the aircraft or engine type certificate, an STC, or an AMOC.

Costs of Compliance

    The FAA estimates that this AD, if adopted as proposed, could 
affect 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 proposed AD:

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


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

    This proposed AD would provide 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

    The FAA determined that this proposed AD would not have federalism 
implications under Executive Order 13132. This proposed AD would 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

[[Page 45041]]

responsibilities among the various levels of government.
    For the reasons discussed above, I certify this proposed 
regulation:
    (1) Is not a ``significant regulatory action'' under Executive 
Order 12866,
    (2) Would not affect intrastate aviation in Alaska, and
    (3) Would 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 Proposed Amendment

    Accordingly, under the authority delegated to me by the 
Administrator, the FAA proposes to amend 14 CFR part 39 as follows:

PART 39--AIRWORTHINESS DIRECTIVES

    1. The authority citation for part 39 continues to read as follows:

    Authority:  49 U.S.C. 106(g), 40113, 44701.


Sec.  39.13   [Amended]

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

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

(a) Comments Due Date

    The FAA must receive comments on this airworthiness directive 
(AD) by November 4, 2022.

(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. 
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).
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(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 (j)(1) through (7) or 
(k) 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 (j)(1) through (7) or (k) of this AD, it must 
be removed from service before further flight.
    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) Inspections Without Removal of the V-Band Coupling

    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 (j)(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.
    (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 (j)(2) through (7) of this AD, do the 
inspections in paragraph (k) 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 (k)(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 (j)(5) through (7) of this AD, do the inspections in 
paragraph (k) 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

[[Page 45046]]

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.

(k) 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 (k)(1) and (2) of this AD if required by paragraph (j)(1) 
or (4) of this AD or as an alternative to the inspections required 
by paragraph (j) 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 (j) or (k) of 
this AD.
    (i) Using crocus 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 (k)(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] TP27JY22.006

    (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 (k)(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 (k)(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 (k)(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.

(l) 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 (j) or (k) 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 
(j) or (k) 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.

(m) 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 Office, send it to 
the attention of the person identified in paragraph (n)(1) of this 
AD 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.

(n) Related Information

    (1) For more information about this AD, contact Thomas Teplik, 
Aviation Safety Engineer, Wichita ACO 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 www.regulations.gov by searching for 
and locating Docket No. FAA-2022-0891.

(o) Material Incorporated by Reference

    None.

    Issued on July 20, 2022.
Christina Underwood,
Acting Director, Compliance & Airworthiness Division, Aircraft 
Certification Service.
[FR Doc. 2022-16139 Filed 7-25-22; 4:15 pm]
BILLING CODE 4910-13-P


