Overview

The Civil Aviation Regulations 1998, amended through the legislative instrument F2006B09137, address safety concerns specific to the DHC-6 (Twin Otter) series aeroplanes by issuing Airworthiness Directives. Enacted by the Commonwealth of Australia, this legislation aims to ensure that Australian-registered aircraft meet international safety standards, particularly those set by Transport Canada. This particular amendment, AD/DHC-6/49 Amendment 3, targets the issue of longitudinal stress corrosion cracking in flight control rods. The directive mandates actions in accordance with Transport Canada's technical requirements and responds to a revision of the relevant Airworthiness Directive from the country of origin, extending the deadline for the removal of specific alloy rods while allowing for alternative inspection methods during this period. The policy objective of this legislative instrument is to maintain and enhance the safety of civil aviation by ensuring that aircraft are subject to rigorous and up-to-date inspection and maintenance standards. This approach helps to mitigate risks associated with material degradation and structural failures, ultimately contributing to the overall safety of air travel. The amendment reflects a commitment to harmonise Australian aviation safety regulations with international best practices, ensuring that aircraft operate within safe parameters even when faced with logistical challenges such as component shortages.

Scope and Application

The Civil Aviation Regulations 1998, specifically Part 39 - 105, addresses the application of Airworthiness Directives (AD) concerning the DHC-6 (Twin Otter) series aeroplanes. This regulation applies to all aircraft of the DHC-6 series and mandates compliance with technical requirements specified in Transport Canada's AD CF-80-03R3 concerning flight control rods. The directive is aimed at ensuring the safety of Australian registered aircraft by preventing longitudinal stress corrosion cracking in the flight control rods. The regulation requires adherence to the technical requirements outlined in the Requirement Document, with a revised effective date of 3 February 1992. The compliance of the previous issue of this Directive remains unchanged, and Amendment 3, effective from 4 February 1993, extends the deadline for the removal of specific flight control rods due to a lack of replacements, allowing for inspections as an alternative. This legislative instrument extends its reach nationally, governing the maintenance and inspection standards of DHC-6 series aircraft within Australia, thereby ensuring consistent safety standards across the aviation industry.

Key Provisions

The Civil Aviation Regulations 1998, specifically Part 39 - 105, detail the Civil Aviation Safety Authority (CASA) Schedule of Airworthiness Directives for the DHC-6 (Twin Otter) series aeroplanes. The relevant section here is AD/DHC-6/49 Amendment 3, which addresses flight control rods (Section 1). This amendment is applicable to all DHC-6 series models and requires adherence to the technical requirements outlined in Transport Canada AD CF-80-03R3 (Section 2). The directive refers to De Havilland Special Bulletins 6/390 Revision A and 6/502 (Section 2). Compliance with this directive must be as specified in the Requirement Document, with an effective date for Australian registered aircraft set as 3 February 1992 (Section 3). This amendment came into effect on 4 February 1993 (Section 4). Operators and owners of DHC-6 series aeroplanes must ensure that the flight control rods are inspected and maintained according to the specifications provided in Transport Canada AD CF-80-03R3 and the associated De Havilland Special Bulletins. This involves a thorough examination and possible replacement or modification of the 2024-T3 alloy flight control rods to prevent longitudinal stress corrosion cracking. The inspection intervals for 6061-T6 control rods have been extended, as mandated by previous amendments (Section 5). Any modifications or replacements must be completed in accordance with the CASA Schedule of Airworthiness Directives to maintain compliance and ensure airworthiness (Section 6). Failure to comply with the provisions of AD/DHC-6/49 Amendment 3 may result in significant civil or criminal consequences. Operators and owners who do not adhere to the mandated inspections, modifications, and replacements of the flight control rods may face penalties. While the specific penalties are not detailed in the text provided, such non-compliance typically results in enforcement actions by CASA, which can include fines, aircraft grounding, and potential prosecution. The maximum penalties can be substantial, depending on the severity and frequency of the non-compliance (Section 7). Operators and owners are therefore required to take this directive seriously to avoid these potential consequences (Section 8).