AD 2024-14-03

This AD is effective August 20, 2024.

AD Docket: You may examine the AD docket at regulations.gov under 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 final rule, any comments received, and other information. The address for Docket Operations is U.S. Department of Transportation, Docket Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue SE, Washington, DC 20590.

Christopher Withers, Aviation Safety Engineer, FAA, 1801 S Airport Road, Wichita, KS 67209; phone: (316) 946-4190; email: christopher.d.withers@faa.gov.

The FAA issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 by adding an AD that would apply to various airplanes modified with a certain configuration of the Garmin GFC 500 Autopilot System installed per STC No. SA01866WI. The NPRM published in the Federal Register on October 10, 2023 (88 FR 69891). The NPRM was prompted by a report of an un-commanded automatic pitch trim runaway when the autopilot was first engaged. In the NPRM, the FAA proposed to require updating the applicable Garmin GFC 500 Autopilot System software for your airplane and prohibit installing earlier versions of that software.

The FAA issued a supplemental notice of proposed rulemaking (SNPRM) to amend 14 CFR part 39 by adding an AD that would apply to various airplanes modified with a certain configuration of the Garmin GFC 500 Autopilot System installed per STC No. SA01866WI. The SNPRM published in the Federal Register on April 17, 2024 (89 FR 27398). The SNPRM was prompted by comments received on the NPRM. The SNPRM proposed to revise the applicability by removing certain airplane models and adding other airplane models, revised paragraph (e) of the proposed AD to clarify that certain hardware failures affected the primary pitch servo and added Note 1 to paragraph (g) of the proposed AD. The FAA is issuing this AD to address autopilot software that does not properly handle certain hardware failures of the primary pitch servo. The unsafe condition, if not addressed, could result in un-commanded automatic pitch trim runaway and loss of control of the airplane.

The FAA received one comment from the National Transportation Safety Board (NTSB). The NTSB supported the SNPRM without change.

The FAA reviewed the relevant data, considered the comment received, and determined that air safety requires adopting the AD as proposed. Accordingly, the FAA is issuing this AD to address the unsafe condition on these products. This AD is adopted as proposed in the SNPRM.

The FAA estimates that this AD affects 5,900 airplanes of U.S. registry.

The FAA estimates the following costs to comply with this AD:

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.

This AD will not have federalism implications under Executive Order 13132. This AD will not have a substantial direct effect on the States, on the relationship between the national government and the States, or on the distribution of power and responsibilities among the various levels of government.

For the reasons discussed above, I certify that this AD:

(1) Is not a “significant regulatory action” under Executive Order 12866,

(2) Will not affect intrastate aviation in Alaska, and

(3) Will not have a significant economic impact, positive or negative, on a substantial number of small entities under the criteria of the Regulatory Flexibility Act.

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

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

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