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[Federal Register Volume 86, Number 164 (Friday, August 27, 2021)]
[Proposed Rules]
[Pages 48070-48078]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2021-18385]

[[Page 48070]]

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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).

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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: [email protected]; 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: [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-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

[[Page 48071]]

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
----------------------------------------------------------------------------------------------------------------
                                                                                     Cost per      Cost on U.S.
                Action                         Labor cost           Parts cost        product        operators
----------------------------------------------------------------------------------------------------------------
Modify fuel probe interface and         8 work-hours x $85 per               $10            $690        $634,800
 recalibrate the fuel system.            hour = $680.
----------------------------------------------------------------------------------------------------------------

    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

0
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]

0
2. The FAA amends Sec.  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.
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(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: [email protected] or [email protected].
    (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: [email protected]; 
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]
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