AD/LYC/78 Amdt 6 Thermostatic Oil Cooler Bypass Valve

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Legislation au F2021L00479 In force Legislative Instrument

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Explanatory Statement

Civil Aviation Safety Regulations 1998

AD/LYC/78 Amdt 6 — Thermostatic Oil Cooler Bypass Valve

Legislation

Under section 98 of the Civil Aviation Act 1988 (the Act), the Governor-General may make regulations for the purpose of carrying out and giving effect to the provisions of the Convention on International Civil Aviation relating to safety, amongst other things. Under regulation 39.001 of the Civil Aviation Safety Regulations 1998 (CASR), the Civil Aviation Safety Authority (CASA) may issue an airworthiness directive (AD) for a kind of aircraft or aeronautical product. Under subsections 98 (5B) and (5BA) of the Act, an AD is a legislative instrument unless it is expressed to apply in relation to a particular person, a particular aircraft or a particular aeronautical product.

Subsection 98 (5D) of the Act provides that a legislative instrument made under the Act or the regulations may apply, adopt or incorporate any matter contained in any instrument or other writing as in force or existing from time to time, even if the other instrument or writing does not yet exist when the legislative instrument is made.

Under subsection 33 (3) of the Acts Interpretation Act 1901, where an Act confers a power to make, grant or issue any instrument of a legislative or administrative character (including rules, regulations or by-laws), the power shall be construed as including a power exercisable in the like manner and subject to the like conditions (if any) to repeal, rescind, revoke, amend, or vary any such instrument.

Under Annex 8 to the Convention on International Civil Aviation, the State of Design has overall responsibility for continuing airworthiness of an aircraft type, and must provide any information necessary to ensure the continuing airworthiness of a type to appropriate States of Registry. ADs (and their equivalents) are the most common form of continuing airworthiness information, and are issued by most International Civil Aviation Organization Contracting States.

The State of Registry of an individual aircraft is responsible for its continuing airworthiness. Under Annex 8, the State of Registry must develop or adopt requirements to ensure the continuing airworthiness of aircraft.

CASA issued AD/LYC/78 Amdt 5 - Thermostatic Oil Cooler Bypass Valve, to correct an unsafe situation on Lycoming Piston Engines. The AD was issued in response to field reports of loose crimp nuts on thermostatic oil cooler bypass valves that could detach and drop into the engine causing severe damage. The State of Design for the engine type, the United States of America Federal Aviation Administration (FAA), has not yet taken action to correct this unsafe condition. As there are many examples of the engine type on the Australian register, CASA has developed an AD to correct the problem on Australian aircraft. As a result of a request from industry, CASA has issued AD/LYC/78 Amdt 6 to update the applicability and requirement statements to reflect the most recent version of the requirement document, Lycoming Service Bulletin No. 518D. This AD repeals and replaces the previous AD on this subject.

Documents Incorporated by Reference

Lycoming Service Bulletin No. 518D, Inspection of Thermostatic Oil Cooler Bypass Valves, issued 16 August 2016, identifies a revised applicability list and updates corrective action details. For subsection 98 (5D) of the Act, the technical document is incorporated as in force from time to time. The technical document is freely available from Lycoming’s website at:

https://www.lycoming.com/node/15796

 

Consultation

This AD is being made at the request of industry, in particular an operator of affected Lycoming piston engines. As this AD amendment is of a minor or machinery nature and does not substantially alter existing arrangements apart from clarifying the affected part number range and updating corrective actions after inspection, it is CASA’s view that it was not necessary or appropriate to undertake any further consultation under section 17 of the Legislation Act 2003.

Regulation Impact Statement

A Regulation Impact Statement (RIS) is not required because ADs are covered by a standing agreement between CASA and the Office of Best Practice Regulation under which a RIS is not required for ADs (OBPR id. 14507).

Statement of Compatibility with Human Rights

A Statement of Compatibility with Human Rights is at Attachment 1.

Making and commencement

The instrument has been made by a delegate of CASA relying on the power of delegation under subregulation 11.260 (1) of CASR and subsection 94 (1) of the Act.

The instrument commences on 7 May 2021.

[Instrument number AD/LYC/78 Amdt 6]


Attachment 1

Statement of Compatibility with Human Rights

Prepared in accordance with Part 3 of the
Human Rights (Parliamentary Scrutiny) Act 2011

AD/LYC/78 Amdt 6 — Thermostatic Oil Cooler Bypass Valve

This legislative instrument is compatible with the human rights and freedoms recognised or declared in the international instruments listed in section 3 of the Human Rights (Parliamentary Scrutiny) Act 2011.

Overview of the legislative instrument

The Civil Aviation Safety Authority (CASA) issued AD/LYC/78 Amdt 5 affecting Lycoming Piston Engines in 1995. The State of Design for the engine type, the United States of America Federal Aviation Administration (FAA), has not yet taken action to correct this unsafe condition. As there are many examples of the engine type on the Australian register, CASA has developed an AD to correct the problem on Australian aircraft. As a result of a request from industry, CASA has issued AD/LYC/78 Amdt 6 to update the applicability and requirement statements to reflect the most recent version of the requirement document, Lycoming Service Bulletin No. 518D

The primary purpose of this legislative instrument is to clarify the affected part number range and update corrective actions after inspection.

Human rights implications

This legislative instrument does not engage any of the applicable rights or freedoms.

Conclusion

This legislative instrument is compatible with human rights as it does not raise any human rights issues.

Civil Aviation Safety Authority

Overview

The Civil Aviation Safety Regulations 1998 were enacted to ensure the safety of civil aviation in Australia, aligning with the provisions of the Convention on International Civil Aviation. The regulations empower the Civil Aviation Safety Authority (CASA) to issue airworthiness directives (ADs) to maintain the airworthiness of aircraft. The AD/LYC/78 Amdt 6, introduced by CASA, targets the issue of loose crimp nuts on thermostatic oil cooler bypass valves in Lycoming Piston Engines, a problem identified in field reports that could lead to severe engine damage if left unaddressed. This amendment was prompted by a request from industry to update the directive to reflect the latest Lycoming Service Bulletin No. 518D, clarifying the affected part number range and updating corrective actions. The amendment does not substantially alter existing arrangements, and therefore, further consultation was deemed unnecessary. The AD repeals and replaces the previous AD on this subject, ensuring that the most current safety standards are applied to aircraft within Australia's jurisdiction.

Scope and Application

The Civil Aviation Safety Regulations 1998, as amended by AD/LYC/78 Amdt 6, apply to any person, entity, or aircraft operator within the Australian jurisdiction that uses Lycoming piston engines. This includes all aircraft registered in Australia that are equipped with these engines, regardless of whether they are used for commercial, private, or charter purposes. The regulation seeks to ensure the safety of these aircraft by addressing the identified unsafe condition of loose crimp nuts on thermostatic oil cooler bypass valves, which could potentially detach and cause severe engine damage. The regulation mandates corrective actions to ensure continued airworthiness of the affected engines, as per the updated Lycoming Service Bulletin No. 518D. While the Act and its subordinate instruments provide a comprehensive framework for addressing such safety concerns, there are no stated exclusions or exemptions in this specific amendment. The scope of the regulation is intended to be nationally consistent with the requirements set out in international aviation safety standards.

Key Provisions

The main operative sections of the Civil Aviation Safety Regulations 1998 (CASR) relevant to this piece of legislation include section 98, which grants the Governor-General the power to make regulations for the purpose of carrying out and giving effect to the Convention on International Civil Aviation relating to safety. Regulation 39.001 specifically allows the Civil Aviation Safety Authority (CASA) to issue airworthiness directives (AD) for a kind of aircraft or aeronautical product. The legislative instrument, AD/LYC/78 Amdt 6, aims to address an unsafe situation on Lycoming Piston Engines by updating the applicability and requirement statements to reflect the most recent version of the requirement document, Lycoming Service Bulletin No. 518D. The obligations imposed by the Act on the parties or entities it governs include the requirement for the State of Design to provide necessary information to ensure the continuing airworthiness of an aircraft type. In this instance, the United States of America Federal Aviation Administration (FAA) is responsible for the Lycoming Piston Engines. CASA, as the State of Registry for Australian aircraft, must develop or adopt requirements to ensure the continuing airworthiness of aircraft registered in Australia. CASA has issued AD/LYC/78 Amdt 6 to correct an unsafe condition identified in the field and to ensure the safe operation of Lycoming Piston Engines in Australia. The AD/LYC/78 Amdt 6 includes specific requirements for operators and maintainers of Lycoming Piston Engines. Operators must ensure that the engines on their aircraft are inspected according to the updated requirements and that any corrective actions identified during the inspection are implemented. Maintainers are responsible for performing the inspections and corrective actions as specified in Lycoming Service Bulletin No. 518D. Failure to comply with these requirements may result in the aircraft being deemed unairworthy, which could lead to enforcement actions by CASA. While specific penalties for non-compliance with ADs are not outlined in the Act, CASA has the authority to take enforcement actions under section 14ZA of the Civil Aviation Act 1988, which includes the power to issue fines and impose other penalties for non-compliance with safety regulations.

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Sourced from the Federal Register of Legislation at 26 August 2026. For the latest information on Australian Government law please go to https://www.legislation.gov.au.