SUPPLEMENTARY INFORMATION:

Comments Invited

The FAA invites you to send any written data, views, or arguments about this final rule. Send your comments using a method listed under the ADDRESSES section. Include “Docket No. FAA-2026-7216; Project Identifier MCAI-2026-00693-A” at the beginning of your comments. The most helpful comments reference a specific portion of the final rule, 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 final rule 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 final rule.

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 AD 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 AD, 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 AD. Submissions containing CBI should be sent to Zakaria Abdi, Aviation Safety Engineer, FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590. 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 European Union Aviation Safety Agency (EASA), which is the Technical Agent for the Member States of the European Union, has issued EASA Emergency AD 2026-0125-E, dated June 29, 2026 (EASA Emergency AD 2026-0125-E). EASA Emergency AD 2026-0125-E states that occurrences of uncommanded rudder deflection were reported due to a cracked NLG hydraulic actuator rod end. Investigation revealed that a crack in the NLG hydraulic actuator rod end could lead to failure of the NLG actuator and interference with the rudder control system, forcing the rudder into left-hand deflection. The affected parts are installed on DAI Model DA 42, DA-42 M, DA 42 NG, and DA 42 M-NG airplanes. This condition, if not detected and corrected, could lead to restricted rudder travel in the landing gear retracted configuration and result in reduced control of the airplane. EASA later revised EASA Emergency AD 2026-0125 with EASA AD 2026-0125R1, dated June 30, 2026 (EASA AD 2026-0125R1) (also referred to as the MCAI) to revise the applicability of certain actions. The MCAI requires revising the existing AFM for your airplane to provide the flight crew with revised operating limitations, repetitively inspecting certain NLG hydraulic actuator rod ends for cracks, corrosion, deformation, damage, and free movement of the spherical bearing, and depending on the results of any inspection, replacing the affected NLG hydraulic actuator rod end with a serviceable part. The MCAI also prohibits the installation of an affected NLG hydraulic actuator rod end unless certain conditions are met.

You may examine the MCAI in the AD docket at regulations.gov under Docket No. FAA-2026-7216.

Material Incorporated by Reference Under 1 CFR Part 51

The FAA reviewed Diamond Aircraft Mandatory Service Bulletin (MSB) 42-154 and MSB 42NG-101, dated June 29, 2026 (issued as one document), published with Diamond Aircraft Work Instruction WI-MSB 42-154 and WI-MSB 42NG-101, dated June 29, 2026 (issued as one document). This material specifies procedures for inspecting certain NLG hydraulic actuator rod ends for cracks, deformation, corrosion, damage, and free movement of the spherical bearing. This material also specifies replacing any NLG hydraulic actuator rod end found with cracks, corrosion, deformation, damage, or lack of free movement of the spherical bearing with a serviceable part. This material also includes a reporting requirement of the results of the first inspection. In addition, the material specifies sending any damaged parts to DAI. 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.

FAA's Determination

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 and material referenced above. The FAA is issuing this AD after determining that the unsafe condition described previously is likely to exist or develop on other products of the same type design.

AD Requirements

This AD requires revising the Limitations section of the existing AFM for your airplane to provide the flight crew with revised operating limitations, repetitively inspecting certain NLG hydraulic actuator rod ends cracks, deformation, corrosion, damage, and free movement of the spherical bearing, and, depending on the results of the inspection, replacing the affected NLG hydraulic actuator rod end with a serviceable part. This AD also prohibits the installation of an affected NLG hydraulic actuator rod end unless certain conditions are met.

The owner/operator (pilot) holding at least a private pilot certificate may revise the existing AFM and must enter compliance with the applicable paragraph of this AD into the airplane maintenance records in accordance with 14 CFR 43.9(a) and 14 CFR 91.417(a)(2)(v). The record must be maintained as required by 14 CFR 91.417, 121.380, or 135.439. This action can be performed equally well by a pilot or a mechanic. This is an exception to the FAA's standard maintenance regulations.

Differences Between This AD and the MCAI and Referenced Material

The MCAI applies to DAI Model 42 M airplanes, but this AD does not include this model because it does not have an FAA type certificate.

The referenced material specifies to return damaged parts to the manufacturer. However, this AD does not require this action. ( printed page 44742)

Interim Action

The FAA considers that this AD is an interim action. If final action is later identified, the FAA might consider further rulemaking.

Justification for Immediate Adoption and Determination of the Effective Date

Section 553(b) of the Administrative Procedure Act (APA) (5 U.S.C. 551 et seq.) authorizes agencies to dispense with notice and comment procedures for rules when the agency, for “good cause,” finds that those procedures are “impracticable, unnecessary, or contrary to the public interest.” Under this section, an agency, upon finding good cause, may issue a final rule without providing notice and seeking comment prior to issuance. Further, section 553(d) of the APA authorizes agencies to make rules effective in less than thirty days, upon a finding of good cause.

An unsafe condition exists that requires the immediate adoption of this AD without providing an opportunity for public comments prior to adoption. The FAA has found that the risk to the flying public justifies forgoing notice and comment prior to adoption of this rule because the FAA has determined that a cracked NLG hydraulic actuator rod end could lead to failure of the NLG actuator and interference with the rudder control system. This can result in restricted rudder travel in the landing gear retracted configuration and reduced control of the airplane. Because this condition can occur without warning and vary from airplane to airplane, the FAA is requiring an immediate flight operating restriction for those airplanes that have 1,000 hours total time-in-service and a compliance time for inspections for some airplanes as low as 5 flight cycles. These compliance times are shorter than the time necessary for the public to comment and for publication of the final rule. Accordingly, notice and opportunity for prior public comment are impracticable and contrary to the public interest pursuant to 5 U.S.C. 553(b).

In addition, the FAA finds that good cause exists pursuant to 5 U.S.C. 553(d) for making this amendment effective in less than 30 days, for the same reasons the FAA found good cause to forgo notice and comment.

Regulatory Flexibility Act

The requirements of the Regulatory Flexibility Act (RFA) do not apply when an agency finds good cause pursuant to 5 U.S.C. 553 to adopt a rule without prior notice and comment. Because the FAA has determined that it has good cause to adopt this rule without prior notice and comment, RFA analysis is not required.

Costs of Compliance

The FAA estimates that this AD affects 267 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 necessary replacements 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 replacements.

The FAA has included all known costs in its cost estimate. According to the manufacturer, however, some of the costs of this AD may be covered under warranty, thereby reducing the cost impact on affected operators.

Paperwork Reduction Act

A federal agency may not conduct or sponsor, and a person is not required to respond to, nor shall a person be subject to a penalty for failure to comply with a collection of information subject to the requirements of the Paperwork Reduction Act unless that collection of information displays a currently valid OMB Control Number. The OMB Control Number for this information collection is 2120-0056. Public reporting for this collection of information is estimated to take approximately 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing the collection of information. All responses to this collection of information are mandatory. Send comments regarding this burden estimate or any other aspect of this collection of information, including suggestions for reducing this burden, to: Information Collection Clearance Officer, Federal Aviation Administration, 10101 Hillwood Parkway, Fort Worth, TX 76177-1524.

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 ( printed page 44743) 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

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, and

(2) Will not affect intrastate aviation in Alaska.

The Amendment

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