48070 Federal Register / Vol. 86, No. 164 / Friday, August 27, 2021 / Proposed Rules 
DEPARTMENT OF TRANSPORTATION 
Federal Aviation Administration 
14 CFR Part 39 
[Docket No. FAA–2021–0715; Project 
Identifier AD–2021–00259–A] 
RIN 2120–AA64 
Airworthiness Directives; Various 
Airplanes 
AGENCY : Federal Aviation 
Administration (FAA), DOT. 
ACTION : Notice of proposed rulemaking 
(NPRM). 
SUMMARY : The FAA proposes to adopt a 
new airworthiness directive (AD) for various airplanes modified with certain configurations of Garmin G3X Touch Electronic Flight Instrument System installed per Supplemental Type Certificate (STC) No. SA01899WI or Garmin GI 275 Multi-Function Display System (MFDS) installed per STC No. SA02658SE. This proposed AD was prompted by a report of a fuel quantity disparity between the amount of fuel indicated and the actual amount of fuel. This proposed AD would require modifying the resistive fuel probe interface. 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 October 12, 2021. 
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 
https://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. 
For service information identified in 
this NPRM, contact Garmin International, Garmin Aviation Support, 1200 E 151st Street, Olathe, KS 66062; phone: (866) 739–5687; email: avionics@garmin.com; website: https://
fly.garmin.com/fly-garmin/support/. You may view this service information at the FAA, Airworthiness Products Section, Operational Safety Branch, 901 Locust, Kansas City, MO 64106. For information on the availability of this material at the FAA, call (816) 329– 
4148. 
Examining the AD Docket 
You may examine the AD docket at 
https://www.regulations.gov by 
searching for and locating Docket No. 
FAA–2021–0715; 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 : 
Kevin Marks, Aviation Safety Engineer, Wichita ACO Branch, FAA, 1801 Airport Road, Wichita, KS 67209; phone: (316) 946–4153; fax: (316) 946– 4107; email: kevin.marks@faa.gov or 
Wichita-COS@faa.gov. 
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–2021–0715; Project Identifier AD– 2021–00259–A’’ 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 https://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. 
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 to Kevin Marks, Aviation Safety Engineer, Wichita ACO Branch, FAA, 1801 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 
The FAA was notified of a Piper 
production line issue with the 
installation of a Garmin G3X Touch Electronic Flight Instrument System installed under STC No. SA01899WI. After calibration and fueling the airplane to a known level, the flight crew noted that the fuel quantity indicator displayed a higher level of fuel. 
The Garmin G3X Touch Electronic 
Flight Instrument System, when interfaced with the Garmin GEA 24 (Engine Airframe Adapter) for display of the fuel quantity, uses a 1K ohm resistor inline between the GEA 24 and the airplane fuel quantity resistance style sending unit (float). This resistor provides lightning protection to the fuel tank as required by 14 CFR 23.954. 
Use of the 1K resistor causes a GEA 
error with changing resistor temperature. The farther the actual (ambient) temperature of the resistor is from the temperature of the fuel quantity calibration, the larger the error. The lower the operating resistance of the fuel sending unit, the larger the error. The largest errors occur in installations with fuel sending units having an operational range less than 100 ohms. The Garmin GI 275 MFDS installed under STC No. SA02658SE, when interfaced with the Garmin GEA 24 for display of the fuel quantity, is also subject to this unsafe condition. 
The displayed fuel quantity can have 
an error as much as four gallons/fuel tank with the display indicating four gallons with an empty tank. This condition, if not addressed, could result in fuel starvation and engine shutdown with consequent loss of airplane control. 
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. 
Related Service Information Under 1 
CFR Part 51 
The FAA reviewed Garmin 
Mandatory STC Service Bulletin No. 2134, Revision A, and Garmin 
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Mandatory STC Service Bulletin No. 
2135, Revision A, both dated April 23, 2021. This service information specifies procedures for modifying the GEA 24 resistive fuel probe interface. These documents are distinct since they apply to different STCs. This service information is reasonably available because the interested parties have access to it through their normal course of business or by the means identified 
in 
ADDRESSES . 
Other Related Service Information 
The FAA also reviewed Master 
Drawing List (MDL) Document No. 005– 01320–00, Revision 10, for STC No. SA01899WI, and MDL Drawing No. 
005–01208–41, Revision 10, for STC No. SA02658SE, both dated April 23, 2021. This service information contains the type design data for installation of the STC. Revision 10 introduces a new fuel quantity interface and configuration to eliminate the unsafe condition described previously. 
Proposed AD Requirements in This 
NPRM 
This proposed AD would require 
modifying the resistive fuel probe 
interface. The proposed AD would apply to airplanes on the approved model list for STC No. SA01899WI, installed in accordance with MDL 
Document No. 005–01320–00, Revision 9 or earlier, and STC No. SA02658SE, installed in accordance with MDL Drawing No. 005–01208–41, Revision 9 or earlier, if the installation is interfaced with a Garmin Engine Adapter GEA 24 connected to resistive fuel probes. 
Costs of Compliance 
The FAA estimates that this AD, if 
adopted as proposed, would affect 920 
airplanes of U.S. registry. 
The FAA estimates the following 
costs to comply with this proposed AD: 
ESTIMATED COSTS  
Action Labor cost Parts cost Cost per 
product Cost on U.S. 
operators 
Modify fuel probe interface and recalibrate 
the fuel system.8 work-hours × $85 per hour = $680 ............. $10 $690 $634,800 
The FAA has included all known 
costs in its cost estimate. According to 
the manufacturer, however, some of the costs of this proposed AD may be covered under warranty, thereby reducing the cost impact on affected operators. 
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 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. 
§ 39.13 [Amended] 
■2. The FAA amends § 39.13 by adding 
the following new airworthiness directive: Various Airplanes: Docket No. FAA–2021– 
0715; Project Identifier AD–2021–00259– 
A. 
(a) Comments Due Date 
The FAA must receive comments on this 
airworthiness directive (AD) by October 12, 2021. 
(b) Affected ADs 
None. 
(c) Applicability 
This AD applies to all serial numbers of the 
airplane models listed in table 1 to paragraph 
(c), certificated in any category, that are either: 
(1) Modified with a Garmin G3X Touch 
Electronic Flight Instrument System under Supplemental Type Certificate (STC) No. SA01899WI, installed in accordance with Master Drawing List (MDL) Document No. 005–01320–00, Revision 9 or earlier, interfaced with a Garmin Engine Adapter GEA 24 connected to resistive fuel probes; or 
(2) Modified with a Garmin GI 275 Multi- 
Function Display System under STC No. SA02658SE, installed in accordance with MDL Revision 9 or earlier, interfaced with a Garmin Engine Adapter GEA 24 connected to resistive fuel probes. 
Note 1 to paragraph (c): Garmin 
Mandatory STC Service Bulletin No. 2134, Revision A, and Garmin Mandatory STC Service Bulletin No. 2135, Revision A, both dated April 23, 2021, contain information for how to determine if your airplane has a resistive probe interface. 
BILLING CODE 4910–13–P 
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EP27AU21.000</GPH> EP27AU21.001</GPH>lotter on DSK11XQN23PROD with PROPOSALS1Table 1 to Paragraph ( c ')-Affected Airplanes 
Type Certificate Holder 
Aermacchi S.p.A. 
Aeronautica Macchi S.p.A./ Aerfer-Industrie 
Aerospaziali Meridionali S.p.A. 
Aerostar Aircraft Corporation 
Air Tractor, Inc. 
Alexandria Aircraft, LLC 
Alpha Aviation Concept Limited 
American Champion Aircraft Corp. 
Aviat Aircraft Inc. 
Bellanca Aircraft Corporation 
B-N Group Ltd. Airplane Model 
F.260, F.260B, F.260C, F.260D, F.260E, 
F.260F, S.205-18/F, S.205-18/R, S.205-
20/F, S.205-20/R, S.205-22/R, S.208, and 
S.208A 
AM-3 
PA-60-600 (Aerostar 600), PA-60-601 
(Aerostar 601), PA-60-601P (Aerostar 
601P), and PA-60-602P (Aerostar 602P) 
AT-401 
14-19, 14-19-2, 14-19-3, 14-19-3A, 17-30, 
17-30A, 17-31, 17-3 lA, 17-3 lATC, and 
17-31 TC 
R2160 
402, 7EC, 7ECA, 7FC, 7GC, 7GCA, 
7GCAA, 7GCB, 7GCBA, 7GCBC, 
7KCAB, 8GCBC, and 8KCAB 
A-1, A-IA, A-lB, A-lC-180, A-lC-200, S­
IS, S-lT, S-2, S-2A, S-2B, S-2C, and S-2S 
14-13, 14-13-2, 14-13-3, and 14-13-3W 
BN-2 and BN-2A 48073 Federal Register / Vol. 86, No. 164 / Friday, August 27, 2021 / Proposed Rules 
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EP27AU21.002</GPH>lotter on DSK11XQN23PROD with PROPOSALS1The Boeing Company 
CEAPR (type certificate previously held by 
APEX Aircraft) 
Cessna Aircraft Company 
Cirrus Design Corporation 
Commander Aircraft Corporation 
Costruzioni Aeronautiche Tecnam S.P.A. 
Cougar Aircraft Corporation 
Cub Crafters, Inc. 
Daher Aircraft Design, LLC (type certificate 
previously held by Quest Aircraft Design, 
LLC) 
De Havilland Support Limited 
Diamond Aircraft Industries Inc. 
Discovery Aviation, Inc. 
Dynac Aerospace Corporation 
EADS-PZL Warszawa-Ok~cie S.A. 
Extra Flugzeugproduktions- und Vertriebs­
GmbH 
FLS Aerospace (Lovaux) Ltd. 
Found Brothers A via ti on Limited 
Frakes Aviation 
FS 2003 Corporation 
Fuji Heavy Industries, Ltd. 
GA8 Airvan (Pty) Ltd. AT-6 (Navy SNJ-2), AT-6A (Navy SNJ-3), 
AT-6B, AT-6C (Navy SNJ-4), AT-6D 
(Navy SNJ-5), AT-6F (Navy SNJ-6), BC­
lA, Navy SNJ-7, and T-6G 
R3000/160 
T-50 (Army AT-17 and UC-78 series, Navy 
JRC-1) 
SR20, SR22, and SR22T 
112, 112B, 112TC, 112TCA, 114, 114A, 
114B, and 114TC 
P2006T 
GA-7 
CC19-180 
Kodiak 100 
B.121 Series 1, B.121 Series 2, and B.121 
Series 3 
DA20-Al, DA20-Cl, DA 40, DA 40 F, and 
DA40NG 
XL-2 
Aero Commander Model 100, Aero 
Commander Model 100-180, Aero 
Commander Model l00A, Volaire Model 
10, and Volaire Model l0A 
PZL-104 Wilga 80, PZL-104M Wilga 
2000, PZL-104MA Wilga 2000, PZL­
KOLIBER 150A, and PZL-KOLIBER 
160A 
EA-300, EA-300/200, EA-300/L, EA 
300/LC, and EA-300/S 
OA7 Optica Series 300 
FBA Centennial 100 
G-44 (Army OA-14, Navy J4F-2) 
(including SCAN Type 30) and G-44A 
PA-12 and PA-12S 
FA-200-160, FA-200-180, and FA-200-
180AO 
GA8 and GA8-TC 320 48074 Federal Register / Vol. 86, No. 164 / Friday, August 27, 2021 / Proposed Rules 
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EP27AU21.003</GPH>lotter on DSK11XQN23PROD with PROPOSALS1Gomolzig Flugzeug- und Maschinenbau 
GmbH 
GROB Aircraft SE 
Helio Aircraft Corporation 
Helio Alaska, Inc. 
Howard Aircraft Foundation 
Interceptor Aircraft Inc. 
The King's Engineering Fellowship 
Legend Aviation & Marine, LLC 
Luscombe Aircraft Corporation 
Maule Aerospace Technology, Inc. 
Micco Aircraft Company, Inc. 
Mooney Aircraft Corporation 
Mooney International Corporation 
Nardi S.A. 
Pacific Aerospace Ltd. 
Piaggio & C. 
Pilatus Aircraft Limited AS 202/15 BRA VO, AS 202/18A BRA VO, 
and AS 202/18A4 BRA VO 
G 115, G 115A, G 115B, G 115C, G 
115C2, G 115D, and G 115D2 
15A and 20 
H-250, H-295 (USAF UIOD), H-391 
(USAF YL-24), H-391B, H-395 (USAF L-
28A or U-1 OB), H-395A, H-700, H-800, 
andHT-295 
DGA-15J (Army UC-70B), DGA-15P 
(Army UC-70, Navy GH-1, GH-2, GH-3, 
NH-1), and DGA-15W 
200, 200A, 200B, 200C, 200D, and 400 
44 Angel, 4500-300, and 4500-300 Series II 
UC-1 
8, 8A, 8B, 8C, 8D, 8E, 8F, and T-8F 
Bee Dee M-4, M-4, M-4-180C, M-4-180S, 
M-4-180T, M-4-180V, M-4-210, M-4-
210C, M-4-210S, M-4-210T, M-4-220, M-
4-220C, M-4-220S, M-4-220T, M-4C, M-
4S, M-4T, M-5-180C, M-5-200, M-5-210C, 
M-5-210TC, M-5-220C, M-5-235C, M-6-
180, M-6-235, M-7-235, M-7-235A, M-7-
235B, M-7-235C, M-7-260, M-7-260C, M-
7-420A, M-7-420AC, M-8-235, M-9-235, 
MT-7-235, MT-7-260, MT-7-420, MX-7-
160, MX-7-160C, MX-7-180, MX-7-180A, 
MX-7-180AC, MX-7-180B, MX-7-180C, 
MX-7-235, MX-7-420, MXT-7-160, MXT-
7-180, and MXT-7-180A 
MAC-125C, MAC-145, MAC-145A, and 
MAC-145B 
M22 
M20, M20A, M20B, M20C, M20D, M20E, 
M20F, M20G, M20J, M20K, M20L, 
M20M, M20R, M20S, and M20TN 
FN-333 
FBA-2C, FBA-2Cl, FBA-2C2, and FBA-
2C3 
P.136-L and P.136-Ll 
PC-6, PC-6/350, PC-6/350-Hl, PC-6/350-
H2, PC-6-Hl, and PC-6-H2 48075 Federal Register / Vol. 86, No. 164 / Friday, August 27, 2021 / Proposed Rules 
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EP27AU21.004</GPH>lotter on DSK11XQN23PROD with PROPOSALS1Piper Aircraft, Inc. 
Polskie Zaklady Lotnicze Spolka zo.o 
Revo, Incorporated 
Robert E. Rust, Jr. 
RUAG Aerospace Services GmbH 
Sierra Hotel Aero, Inc. 
Sky Enterprises, Inc. 
Slingsby Aviation Ltd. 
SOCATA (type certificate currently held by 
Daher) PA-16, PA-16S, PA-18, PA-18-105 
(Special), PA-18-125 (Army L-21A), PA-
18-135, PA-18-150, PA-18A, PA-18A-135, 
PA-18A-150, PA-18AS-125, PA-18AS-
135, PA-18AS-150, PA-18S, PA-18S-105 
(Special), PA-18S-125, PA-18S-135, PA-
18S-150, PA-19 (Army L-18C), PA-19S, 
PA-20, PA-20-115, PA-20-135, PA-20S, 
PA-20S-115, PA-20S-135, PA-22, PA-22-
108, PA-22-135, PA-22-150, PA-22-160, 
PA-22S-135, PA-22S-150, PA-22S-160, 
PA-23, PA-23-160, PA-23-235, PA-23-250, 
PA-23-250 (Navy UO-1), PA-24, PA-24-
250, PA-24-260, PA-24-400, PA-28-140, 
PA-28-150, PA-28-151, PA-28-160, PA-
28-161, PA-28-180, PA-28-181, PA-28-
201 T, PA-28-235, PA-28-236, PA-28R-
180, PA-28R-200, PA-28R-201, PA-28R-
201T, PA-28RT-201, PA-28RT-201T, PA-
28S-160, P A-28S-180, P A-30, P A-31-300, 
PA-32-260, PA-32-300, PA-32-301, PA-
32-301FT, PA-32-301T, PA-32-301XTC, 
PA-32R-300, PA-32R-301 (HP), PA-32R-
301 (SP), PA-32R-301T, PA-32RT-300, 
PA-32RT-300T, PA-32S-300, PA-34-200, 
PA-34-200T, PA-34-220T, PA-38-112, PA-
39, PA-40, PA-44-180, PA-44-180T, PA-
46-310P, PA-46-350P, PA-46R-350T, and 
PA-E23-250 
PZLM26 01 
Colonial Model C-1, Colonial Model C-2, 
Lake Model 250, Lake Model LA-4, and 
Lake Model LA-4-200 
DHC-1 Chipmunk Mk 21, DHC-1 
Chipmunk Mk 22, and DHC-1 Chipmunk 
Mk22A 
Do 27 Q-6, Do 28 A-1, and Do 28 B-1 
Navion (Army L-17 A), Navion A (Army L-
17B and L-l 7C), Navion B, Navion D, 
Navion E, Navion F, Navion G, and Navion 
H 
RC-3 
T67M260 
MS 880B, MS 885, MS 892A-150, MS 
892E-150, MS 893A, MS 893E, MS 894A, 
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EP27AU21.005</GPH>lotter on DSK11XQN23PROD with PROPOSALS1Spartan Aircraft Company 
Swift Museum Foundation, Inc. 
Symphony Aircraft Industries Inc. 
Textron Aviation Inc. Rallye 150 T, Rallye 235C, Rallye 235 E, 
TB9, TB 10, TB 20, TB 21, and TB 200 
7W (Army UC-71) 
GC-IA and GC-IB 
OMF-100-160 and SA 160 
19A, 23, 35, 36, 50, 58, 76, 77, 95, 120, 
140, 140A, 150, 150A, 150B, 150C, 150D, 
150E, 150F, 150G, 150H, 150J, 150K, 
150L, ISOM, 152, 170, 170A, 170B, 172, 
172A, 172B, l 72C, 172D, l 72E, l 72F 
(USAF T-41A), 172G, 172H (USAF T-
41A), 1721, 172K, l 72L, 172M, 172N, 
172P, l 72Q, l 72R, l 72RG, 172S, 175, 
175A, 175B, 175C, 177, 177 A, 177B, 
l 77RG, 180, 180A, 180B, 180C, 180D, 
180E, 180F, 180G, 180H, 180J, 180K, 182, 
182A, 182B, 182C, 182D, 182E, 182F, 
182G, 182H, 182J, 182K, 182L, 182M, 
182N, 182P, 182Q, 182R, 182S, 182T, 185, 
185A, 185B, 185C, 185D, 185E, 190, 195, 
195A, 195B, 206, 206H, 207, 207A, 210, 
210-5 (205), 210-SA (205A), 210A, 210B, 
210C,210D,210E,210F,210G,210H, 
210J, 210K, 210L, 210M, 210N, 210R, 
310,310A,310B,310C,310D,310E,310F, 
310G, 310H, 3101, 310J, 310J-l, 310K, 
310L, 310N, 310P, 310Q, 310R, 320, 320-
1, 320A, 320B, 320C, 320D, 320E, 320F, 
335,336,337,337A,337B,337C,337D, 
337E, 337F, 337G, 337H, 340, 340A, 35-
33, 35-A33, 35-B33, 35-C33, 35-C33A, 
35R, 45 (Military YT-34), 56TC, 58A, 
58PA, 58TCA, 95-55, 95-A55, 95-B55, 95-
B55A, 95-B55B, 95-C55, 95-C55A, 
A150K, A150L, A150M, A152, A185E, 
Al85F, A23, A23-19, A23-24, A23A, A24, 
A24R, A35, A36, A36TC, A45 (Military T-
34A, B-45), A56TC, B19, B23, B24R, B35, 
B36TC, B50, B95, B95A, C23, C24R, C35, 
C50, Dl7S, D35, D45 (Military T-34B), 
DS0E-5990, D55, D55A, D95A, E310H, 
E310J, E33, E33A, E33C, E35, E55, ESSA, 
E95, F150F, F150G, F150H, F150J, 
Fl50K, Fl50L, Fl50M, Fl 52, Fl 72D, 
Fl 72E, Fl 72F, Fl 72G, Fl 72H, Fl 72K, 
Fl 72L, Fl 72M, Fl 72N, Fl 72P, Fl 77RG, 
F182P,F182Q,F33,F33A,F33C,F337E, 
F337F, F337G, F337H, F35, FA150K, 
FA150L, FA150M, FA152, FP172D, 48077 Federal Register / Vol. 86, No. 164 / Friday, August 27, 2021 / Proposed Rules 
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EP27AU21.006</GPH>lotter on DSK11XQN23PROD with PROPOSALS1Thrush Aircraft, LLC 
Topcub Aircraft, Inc. 
True Flight Holdings LLC 
Twin Commander Aircraft LLC 
Univair Aircraft Corporation 
Viking Air Limited 
Vulcanair S.p.A. 
Waco Aircraft Company 
WACO Classic Aircraft Corporation 
WSK PZL Mielec and OBR SK Mielec 
W.Z.D. Enterprises Inc 
ZenairLtd. 
Zlin Aircraft a.s. FR172E, FR172F, FR172G, FR172H, 
FRI 72J, FRI 72K, FR182, FRA150L, 
FRA150M, FT337E, FT337F, FT337GP, 
FT337HP, G17S, G33, G35, G36, G58, 
H35, J35, K35, LC40-550FG, LC41-
550FG, LC42-550FG, M19A, M337B, 
M35, N35, P172D, P206, P206A, P206B, 
P206C, P206D, P206E, P21 ON, P21 OR, 
P337H, P35, R172E, R172F, R172G, 
R172H, R172J, R172K, R182, S35, SD17S, 
T182, T182T, T206H, T207, T207A, 
T210F, T210G, T210H, T210J, T210K, 
T21 0L, T21 OM, T21 ON, T21 OR, T240, 
T303, T310P, T310Q, T310R, T337B, 
T337C, T337D, T337E, T337F, T337G, 
T337H, T337H-SP, TP206A, TP206B, 
TP206C, TP206D, TP206E, TR182, 
TU206A, TU206B, TU206C, TU206D, 
TU206E, TU206F, TU206G, U206, 
U206A, U206B, U206C, U206D, U206E, 
U206F, U206G, V35, V35A, and V35B 
600 S-2D, S2R, S2R-R1340, S2R-R1820, 
S2R-R3S, and S2R-T34 
CC18-180 and CC18-180A 
AA-1, AA-IA, AA-1B, AA-IC, AA-5, 
AA-SA, AA-5B, and AG-5B 
500, 500-A, 520, 560, and 560-A 
108, 108-1, 108-2, 108-3, 108-5, 415-C, 
415-CD, 415-D, A-2, A2-A, E, F-1, F-lA, 
G, and MIO 
DHC-2 Mk.I, DHC-2 Mk.II, DHC-2 
Mk.III, and TR-1 
P.68, P.68 "Observer," P.68B, P.68C, 
P.68C-TC, P.68R, P.68 Observer 2, P.68TC 
Observer, and Vulcanair Vl.0 
YMF 
2T-1A, 2T-1A-1, and 2T-1A-2 
PZLM20 03 
llA and llE 
CH2000 
Z-143L, Z-242L, and Zlin 526L 48078 Federal Register / Vol. 86, No. 164 / Friday, August 27, 2021 / Proposed Rules 
(d) Subject 
Joint Aircraft System Component (JASC) 
Code 2841, Fuel Quantity Indicator. 
(e) Unsafe Condition 
This AD was prompted by reports of fuel 
quantity disparities between the amount of 
fuel indicated and the actual amount of fuel. The FAA is issuing this AD to ensure that the amount of fuel indicated is the amount of fuel available. The unsafe condition, if not addressed, could result in fuel starvation and engine shutdown with consequent loss of airplane control. 
(f) Compliance 
Comply with this AD within the 
compliance times specified, unless already 
done. 
(g) Action 
Within 100 hours time-in-service after the 
effective date of this AD or within 12 months 
after the effective date of this AD, whichever occurs first, modify the fuel probe interface by following the Modification Instructions in Garmin Mandatory STC Service Bulletin No. 2134, Revision A, or Garmin Mandatory STC Service Bulletin No. 2135, Revision A, both dated April 23, 2021, whichever is applicable. 
(h) Alternative Methods of Compliance 
(AMOCs) 
(1) The Manager, Wichita ACO 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 certification office, send it to the attention of the person identified in Related Information. 
(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. 
(i) Related Information 
(1) For more information about this AD, 
contact Kevin Marks, Aviation Safety 
Engineer, Wichita ACO Branch, FAA, 1801 Airport Road, Wichita, KS 67209; phone: (316) 946–4153; fax: (316) 946–4107; email: kevin.marks@faa.gov or Wichita-COS@
faa.gov. 
(2) For service information identified in 
this AD, contact Garmin International, 
Garmin Aviation Support, 1200 E 151st Street, Olathe, KS 66062; phone: (866) 739– 5687; email: avionics@garmin.com; website: 
https://fly.garmin.com/fly-garmin/support/ . 
You may view this referenced service information at the FAA, Airworthiness Products Section, Operational Safety Branch, 901 Locust, Kansas City, MO 64106. For information on the availability of this material at the FAA, call (816) 329–4148. 
Issued on August 20, 2021. 
Lance T. Gant, 
Director, Compliance & Airworthiness 
Division, Aircraft Certification Service. 
[FR Doc. 2021–18385 Filed 8–26–21; 8:45 am] 
BILLING CODE 4910–13–P DEPARTMENT OF TRANSPORTATION 
Federal Aviation Administration 
14 CFR Part 39 
[Docket No. FAA–2021–0713; Project 
Identifier AD–2021–00180–R] 
RIN 2120–AA64 
Airworthiness Directives; Bell Textron 
Inc., Helicopters 
AGENCY : Federal Aviation 
Administration (FAA), DOT. 
ACTION : Notice of proposed rulemaking 
(NPRM). 
SUMMARY : The FAA proposes to adopt a 
new airworthiness directive (AD) for Bell Textron Inc., Model 412, 412EP, and 412CF helicopters. This proposed AD was prompted by evaluation results showing flight loads that impact the collective lever fatigue life. This proposed AD would require adding a permanent life penalty for certain collective levers and prohibit installing those collective levers unless the permanent life penalty has been added. 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 October 12, 2021. 
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 
https://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. 
For service information identified in 
this NPRM, contact Bell Textron, Inc., P.O. Box 482, Fort Worth, TX 76101; telephone 1–450–437–2862 or 1–800– 363–8023; fax 1–450–433–0272; email productsupport@bellflight.com; or at 
https://www.bellflight.com/support/ contact-support. You may view this 
service information at the FAA, Office of the Regional Counsel, Southwest Region, 10101 Hillwood Pkwy., Room 6N–321, Fort Worth, TX 76177. For information on the availability of this material at the FAA, call (817) 222– 5110. Examining the AD Docket 
You may examine the AD docket at 
https://www.regulations.gov by 
searching for and locating Docket No. 
FAA–2021–0713; 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 : 
Haytham Alaidy, Aerospace Engineer, Certification & Program Management Section, DSCO Branch, Compliance & Airworthiness Division, FAA, 10101 Hillwood Pkwy., Fort Worth, TX 76177; telephone (817) 222–5224; email haytham.alaidy@faa.gov. 
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–2021–0713; Project Identifier AD– 2021–00180–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 https://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. 
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 
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