AD 2026-15-18

This AD is effective September 8, 2026.

The Director of the Federal Register approved the incorporation by reference of a certain publication listed in this AD as of September 8, 2026.

AD Docket: You may examine the AD docket at regulations.gov under Docket No. FAA-2026-4636; 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, the mandatory continuing airworthiness information (MCAI), any comments received, and other information. The address for Docket Operations is U.S. Department of Transportation, Docket Operations, M-91, West Building Fifth Floor, Room W58-213, 1200 New Jersey Avenue SE, Washington, DC 20590.

Material Incorporated by Reference:

• For Diamond Aircraft Industries material identified in this AD, contact DAI, 1560 Crumlin Sideroad, London, Ontario, Canada, N5V 1S2; phone: (519) 457-4041, fax: (519) 457-4045; email: support-canada@diamondaircraft.com; website: diamondaircraft.com.

• You may view this material at the FAA, Airworthiness Products Section, Operational Safety Branch, 1100 Main, Kansas City, MO 64105. For information on the availability of this material at the FAA, call (817) 222-5110. It is also available at regulations.gov under Docket No. FAA-2026-4636.

William Reisenauer, Aviation Safety Engineer, FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590; phone: (516) 228-7301; email: ECB-COS@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 certain DAI Model DA20-C1 airplanes. The NPRM was published in the Federal Register on May 15, 2026 (91 FR 27871). The NPRM was prompted by Transport Canada AD CF-2026-03, dated January 21, 2026 AD CF-2026-03) (referred to as the MCAI), issued by Transport Canada, which is the aviation authority for Canada to correct an unsafe condition on all DAI Model DA20-C1 airplanes having an Artex ELT 1000 installed. The MCAI states that DAI received a report of an occurrence where the Artex ELT 1000 installed in a DA20-C1 airplane did not perform as intended. Further investigation by the manufacturer revealed that some Artex ELT 1000 units might not have a jumper wire between the D-sub pins 5 and 12, which could prevent the ELT beacon from being activated by the internal G-Switch and the aural alert buzzer from being activated in the event of an accident.

In the NPRM, the FAA proposed to require a continuity inspection of the D-sub connector of the Artex ELT 1000 and, if necessary, corrective actions. The FAA is issuing this AD to address the unsafe condition on these products.

You may examine the MCAI in the AD docket at regulations.gov under Docket No. FAA-2026-4636.

The FAA received no comments on the NPRM or on the determination of the costs.

These products have been approved by the civil aviation authority of another country and are approved for operation in the United States. Pursuant to the FAA's bilateral agreement with this State of Design Authority, that authority has notified the FAA of the unsafe condition described in the MCAI referenced above. The FAA reviewed the relevant data, considered any comments received, and determined that air safety requires adopting this AD as proposed. Accordingly, the FAA is issuing this AD to address the unsafe condition on these products. Except for minor editorial changes, this AD is adopted as proposed in the NPRM. None of the changes will increase the economic burden on any operator.

The FAA reviewed Diamond Aircraft Industries Mandatory Service Bulletin No. DAC1-25-05 Rev. 1, dated July 19, 2024. This material specifies procedures for performing a continuity inspection on the D-sub connector of the Artex ELT 1000 and, if necessary, installing the jumper wire into the D-sub connector.

This material is reasonably available because the interested parties have access to it through their normal course of business or by the means identified in the ADDRESSES section.

Although step 14 of the Accomplishment/Instructions of Diamond Aircraft Industries Mandatory Service Bulletin DAC1-25-05 Rev. 1, dated July 19, 2024, requires completing and sending an execution report to the manufacturer, this AD does not require that action.

The FAA estimates that this AD affects 365 airplanes of U.S. registry.

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

The FAA estimates the following costs to do any repairs that would be required based on the results of the inspection. The agency has no way of determining the number of airplanes that might need these repairs:

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: