AD/DHC-6/19 - Propeller and Power Control Lever Interlock - Mod - CANCELLED

Overview

The Civil Aviation Act 1988 was enacted to establish a legislative framework for the regulation of civil aviation in Australia, ensuring the safety and efficiency of air navigation. The Act provides the authority for the Governor-General to make regulations necessary for the safety of air navigation, including the issuance of airworthiness directives (ADs) under regulation 39.001 of the Civil Aviation Safety Regulations 1998. These ADs serve as legislative instruments aimed at maintaining the continuing airworthiness of aircraft types, in line with international standards set by the Convention on International Civil Aviation. The Civil Aviation Safety Authority (CASA) is responsible for assessing and issuing such directives when required, and in the case of De Havilland DHC-6 (Twin Otter) model aeroplanes, CASA has determined that a previously issued AD is no longer necessary and has subsequently cancelled it, effective from 20 November 2008. This action was taken without public consultation as it pertains to Australia's obligations under the aforementioned international convention, and no replacement AD is required as the unsafe condition has been resolved.

Scope and Application

The Civil Aviation Act 1988 and the Civil Aviation Safety Regulations 1998 provide the legal framework for the issuance and management of airworthiness directives (ADs) in Australia, focusing on ensuring the safety of air navigation. Regulation 39.001 of the Civil Aviation Safety Regulations 1998 empowers the Civil Aviation Safety Authority (CASA) to issue ADs for specific types of aircraft or aeronautical products. These directives, being disallowable instruments, are legislative instruments under section 46A of the Acts Interpretation Act 1901 and are subject to the provisions of the Legislative Instruments Act 2003. ADs are integral to maintaining the continuing airworthiness of aircraft as mandated by Annex 8 to the Convention on International Civil Aviation, with the State of Design responsible for the initial issuance and the State of Registry tasked with implementing these directives. In Australia, CASA, as the national airworthiness authority, must evaluate and, where necessary, issue corresponding ADs to ensure compliance with international safety standards. The process of AD issuance and cancellation, such as the recent cancellation of AD/DHC-6/19 for De Havilland DHC-6 (Twin Otter) aeroplanes, reflects Australia’s adherence to international obligations and ensures that only necessary safety measures are enforced.

Key Provisions

The Civil Aviation Act 1988, in section 98, grants the Governor-General the authority to make regulations that serve the interests of air navigation safety. This includes the issuance of airworthiness directives (ADs) as stipulated in regulation 39.001 of the Civil Aviation Safety Regulations 1998. An AD, as defined in subregulation 39.001(5), is a disallowable instrument under section 46A of the Acts Interpretation Act 1901, and it is recognised as a legislative instrument pursuant to section 6 of the Legislative Instruments Act 2003. This regulatory framework ensures that airworthiness directives are formally recognised and enforceable within Australia’s civil aviation system. The Act imposes several obligations on the parties involved, particularly the Civil Aviation Safety Authority (CASA). Under Annex 8 of the Convention on International Civil Aviation, the State of Design has the primary responsibility for the continuing airworthiness of an aircraft type, which includes providing necessary information to the State of Registry. CASA, as Australia’s national airworthiness authority, must then assess this information and, if deemed necessary, issue an Australian AD to enforce the requirements of the State of Design. This process ensures that all aircraft registered in Australia maintain their airworthiness according to international standards. The Civil Aviation Safety Regulations 1998 also require the State of Registry to establish or adopt requirements to ensure the continuing airworthiness of individual aircraft. This means that the State of Registry must implement and enforce the regulations set forth by the State of Design when issuing an AD. In the case of the De Havilland DHC-6 Twin Otter model aeroplanes, CASA assessed the AD/DHC-6/19 and determined that the unsafe condition it addressed no longer existed, leading to the cancellation of the Australian AD on 20 November 2008. This action was taken in accordance with Australia’s obligations under the Convention on International Civil Aviation and did not require public consultation or a Regulatory Impact Statement. The legislation also outlines consequences for non-compliance with airworthiness directives. Any breach of the Civil Aviation Safety Regulations 1998 can result in civil or criminal penalties. The specific penalties are not detailed in the provided text, but under general civil aviation law, non-compliance can lead to fines, imprisonment, or both, depending on the severity of the violation. The AD cancellation itself, as noted, was made in compliance with the Act by the Manager, Systems and New Technologies, within the Airworthiness Engineering Group at CASA, further ensuring adherence to the legislative requirements.