AD/DHE/1 - Accessory Drive Shaft - Modification to Provide Weak Neck - CANCELLED

Overview

The Civil Aviation Act 1988, enacted to establish a regulatory framework for ensuring the safety and efficiency of civil aviation, empowers the Governor-General to create regulations, including those pertaining to airworthiness directives. This legislative framework was introduced to address the need for a cohesive and safety-centric approach to the regulation of civil aviation in Australia, ensuring compliance with international standards. Under the authority granted by this Act, the Civil Aviation Safety Regulations 1998 were established, allowing the Civil Aviation Safety Authority (CASA) to issue airworthiness directives for types of aircraft or aeronautical products. These directives serve as legislative instruments, crucial for maintaining the continuing airworthiness of aircraft in accordance with international obligations under the Convention on International Civil Aviation. CASA, as the national airworthiness authority, is responsible for assessing foreign airworthiness directives and, when necessary, issuing corresponding Australian directives to ensure compliance and safety. The process of issuing or cancelling airworthiness directives, such as the recent cancellation of Australian AD/DHE/1 affecting De Havilland Gipsy Six II and Gipsy Queen II engines, is governed by Australia’s commitments under the Convention on International Civil Aviation. CASA, acting on behalf of the Australian government, assesses the necessity of these directives, ensuring that any actions taken align with international standards and obligations. This approach ensures that the Australian civil aviation system maintains high safety standards and international interoperability. The cancellation of AD/DHE/1, effective from 4 June 2009, reflects CASA's commitment to safety and compliance, with no public consultation or regulatory impact statement required as per the Office of Best Practice Regulation's assessment.

Scope and Application

The Civil Aviation Act 1988 and its associated regulations, including the Civil Aviation Safety Regulations 1998, provide the framework within which the Civil Aviation Safety Authority (CASA) issues airworthiness directives (ADs) to ensure the safety of air navigation. Under these regulations, CASA has the authority to issue ADs for particular kinds of aircraft or aeronautical products, which are legislative instruments subject to disallowance and published in accordance with the Legislative Instruments Act 2003. These directives are rooted in Australia's obligations under Annex 8 of the Convention on International Civil Aviation, which mandates that the State of Design is responsible for the continuing airworthiness of an aircraft type and must provide necessary information to States of Registry, including Australia. CASA, as the national airworthiness authority, must assess such information and, where appropriate, issue an Australian AD to ensure compliance with airworthiness requirements. The AD/DHE/1 concerning De Havilland Gipsy Six II and Gipsy Queen II engines has been assessed and subsequently cancelled by CASA, effective from 4 June 2009, due to the resolution of the unsafe condition identified. This cancellation aligns with Australia's international obligations and does not require public consultation or a Regulatory Impact Statement. The AD was made by the Manager Systems and New Technologies within CASA's Airworthiness Engineering Group, in accordance with the Act.

Key Provisions

The Civil Aviation Act 1988 and the Civil Aviation Safety Regulations 1998 establish the framework within which airworthiness directives (ADs) are issued and managed. Under section 98 of the Civil Aviation Act 1988, the Governor-General is empowered to make regulations in the interests of the safety of air navigation, and regulation 39.001 of the Civil Aviation Safety Regulations 1998 enables the Civil Aviation Safety Authority (CASA) to issue ADs for specific types of aircraft or aeronautical products. Section 39.001(5) of these regulations also clarifies that an AD is considered a disallowable instrument under section 46A of the Acts Interpretation Act 1901, and therefore, it is a legislative instrument as per section 6 of the Legislative Instruments Act 2003. This legislative basis ensures that ADs are issued with the authority and formality required to mandate safety measures in the aviation sector. The obligations imposed by these provisions are primarily on CASA, as the national airworthiness authority. Under Annex 8 to the Convention on International Civil Aviation, the State of Design is responsible for ensuring the continuing airworthiness of an aircraft type and must provide necessary information to States of Registry. Consequently, CASA must assess the ADs issued by the State of Design and, if appropriate, issue Australian ADs to enforce these requirements. For example, CASA issued and subsequently cancelled Australian AD/DHE/1 concerning De Havilland Gipsy Six II and Gipsy Queen II engines, reflecting the authority's role in enforcing airworthiness standards. Additionally, the State of Registry is tasked with developing or adopting requirements to ensure the continuing airworthiness of aircraft registered within its jurisdiction, reinforcing the collaborative nature of international aviation safety standards. In terms of compliance and enforcement, the Civil Aviation Safety Regulations 1998 and the overarching legislation set out the consequences for non-compliance with ADs. While the specific offences, penalties, and civil or criminal consequences are not detailed in the provided text, it is clear that failure to adhere to ADs could lead to significant legal repercussions. The cancellation of AD/DHE/1 demonstrates that CASA can take swift action to address unsafe conditions, indicating a stringent approach to enforcing airworthiness directives. The lack of public consultation on this particular AD cancellation, due to Australia’s obligations under the Convention on International Civil Aviation, further underscores the authority and autonomy CASA exercises in managing aviation safety.