DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2023-1990; Project Identifier AD-2023-00734-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 a certain configuration of the
Garmin GFC 500 Autopilot System installed per Supplemental Type
Certificate (STC) No. SA01866WI. This proposed AD was prompted by a
report of an un-commanded automatic pitch trim runaway when the
autopilot was first engaged. This proposed AD would require updating
the applicable Garmin GFC 500 Autopilot System software for your
airplane and would prohibit installing earlier versions of that
software. 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
24, 2023.

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 regulations.gov. Follow
the instructions for submitting comments.
Fax: (202) 493-2251.
Mail: U.S. Department of Transportation, Docket
Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New
Jersey Avenue SE, Washington, DC 20590.
Hand Delivery: Deliver to Mail address above between 9
a.m. and 5 p.m., Monday through Friday, except Federal holidays.
AD Docket: You may examine the AD docket at regulations.gov by
searching for and locating Docket No. FAA-2023-1990; 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: Christopher Withers, Aviation Safety
Engineer, FAA, 1801 S Airport Road, Wichita, KS 67209; phone: (316)
946-4190; email: christopher.d.withers@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-2023-1990; Project Identifier
AD-2023-00734-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
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
Christopher Withers, Aviation Safety Engineer, 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

The FAA received a report of an incident involving a Textron
Aviation Inc. (type certificate previously held by Beech Aircraft
Corporation, Raytheon Aircraft Company, Hawker Beechcraft Corporation,
and Beechcraft Corporation) Model F33A Bonanza airplane having an un-
commanded automatic pitch trim runaway when the autopilot was first
engaged. The airplane was equipped with a Garmin GFC 500 Autopilot
System that included an optional GSA 28 pitch trim servo. The affected
Garmin GFC 500 Autopilot System includes G5, G3X Touch, or GI 275
software and was installed per STC No. SA01866WI using Master Drawing
List 005-01264-00, Revisions 1 through 76.
The affected autopilot system software does not properly handle
certain hardware failures of the pitch trim servo. This could result in
an automatic un-commanded pitch trim runaway, and loss of control of
the airplane.
An investigation by Garmin International and the National
Transportation Safety Board (NTSB) determined this condition could
exist on various Textron Aviation, Inc., Piper Aircraft, Inc.,
Commander Aircraft Corporation, Mooney International Corporation, and
DAHER AEROSPACE airplane models equipped with a Garmin GFC 500
Autopilot System that includes an optional GSA 28 pitch trim servo.

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.

Proposed AD Requirements in This NPRM

This proposed AD would require updating the applicable Garmin GFC
500 Autopilot System software for your airplane and would prohibit
installing earlier versions of that software.

Costs of Compliance

The FAA estimates that this AD, if adopted as proposed, would
affect 5,900 airplanes of U.S. registry.
The FAA estimates the following costs to comply with this proposed
AD:

Estimated Costs

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.

Sec. 39.13 [Amended]

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