Airworthiness Directives; Austro Engine GmbH Engines

SUPPLEMENTARY INFORMATION:

Comments Invited

The FAA invites you to send any written data, views, or arguments about this final rule. Send your comments to an address listed under ADDRESSES . Include “Docket No. FAA-2024-2313; Project Identifier MCAI-2024-00493-E” 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 Morton Lee, Aviation Safety Engineer, FAA, 1200 District Avenue, Burlington, MA 01803. 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 2024-0172-E, dated August 28, 2024 (EASA AD 2024-0172-E) (also referred to as the MCAI), to correct an unsafe condition on certain Austro Model E4 and E4P engines having a piston part number (P/N) E4A-72-400-000. The MCAI states that engine failures have been reported, where, during subsequent inspection, cracks on the piston were identified. During the following investigation, it was determined that only affected parts (pistons P/N E4A-72-400-000) are subject to that failure. Further investigation is on-going to determine the root cause of that failure. This condition, if not corrected, could lead to engine failure with consequent reduced control of the airplane and, for single-engine airplanes, damage to the airplane and injury to occupants during an emergency landing.

You may examine the MCAI in the AD docket at regulations.gov under Docket No. FAA-2024-2313.

Material Incorporated by Reference Under 1 CFR Part 51

The FAA reviewed Austro Mandatory Service Bulletin No. MSB-E4-043/0, dated August 27, 2024, which specifies, among other things, procedures for repetitive BSIs for cracks on the pistons.

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 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, it 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 repetitive BSIs for cracks on the pistons and, if necessary, removal from service and replacement of the piston, and a fuel sample analysis for water contamination and, if contamination is found, replacement of the HPP, injectors, and fuel rails.

Interim Action

The FAA considers that this AD is an interim action. The unsafe condition is still under investigation by the manufacturer and, depending on the results of that investigation, the FAA may consider further rulemaking action.

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 cracks on the pistons, if not corrected, could lead to engine failure with consequent reduced control of the airplane and, for single-engine airplanes, damage to the airplane and injury to occupants during an emergency landing. The FAA has determined that these engines will need to be inspected before 100 or 200 flight hours after installation depending on the engine model. Based on the fleet usage of these engines, many of these engines will need an inspection before further flight and most within 3 months. 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 20 engines installed on airplanes of U.S. registry.

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