AD/DHC-6/27 - Fuel Cell Sump Plate Flapper Valve Seals - Modification

Overview

The Civil Aviation Regulations 1998, administered by the Civil Aviation Safety Authority (CASA), was enacted to regulate and ensure safety within Australia's civil aviation sector. Part 39, specifically addressing airworthiness directives, includes a directive concerning DHC-6 (Twin Otter) Series Aeroplanes. The policy objective of this legislation is to mandate modifications to the fuel cell sump plate flapper valve seals to mitigate the risk of potential failure, thereby enhancing the safety and reliability of these aircraft. The legislative instrument F2006B09114, detailing the compliance requirements, applies to all models with serial numbers 1 to 299 that do not incorporate modification 6/1406. Compliance must be achieved within 100 hours of the aircraft's time in service following 30 June 1971, as stipulated in De Havilland of Canada Service Bulletin No. 6/269.

Scope and Application

The Civil Aviation Regulations 1998, specifically Part 39 - 105, mandates the application of Airworthiness Directives (AD) to ensure the safe operation of civil aircraft within Australia. One such AD, AD/DHC-6/27, concerns the modification of fuel cell sump plate flapper valve seals for DHC-6 (Twin Otter) Series aeroplanes with serial numbers 1 to 299, excluding those that have already incorporated Modification 6/1406. This directive applies to all entities operating such aircraft, ensuring that they adhere to the specified modifications to maintain airworthiness. The regulation is applicable nationally and is enforced by the Civil Aviation Safety Authority. Compliance with the directive is required within 100 hours of time in service after June 30, 1971, as referenced in De Havilland of Canada Service Bulletin No. 6/269. The authority to extend or restrict the application of these regulations may be granted through subordinate instruments, ensuring flexibility in addressing evolving safety concerns.

Key Provisions

The Civil Aviation Regulations 1998, specifically under Part 39 - 105, contain several operative sections that are crucial for ensuring the airworthiness of DHC-6 (Twin Otter) Series Aeroplanes. Section 39.105 (1) outlines the applicability of the Airworthiness Directive (AD) for all models with serial numbers 1 to 299 that have not incorporated Modification 6/1406. This directive is aimed at ensuring the safety of the aircraft by modifying the fuel cell sump plate flapper valve seals (AD/DHC-6/27). Compliance with these directives is mandated within 100 hours of time in service after 30 June 1971, as stated in section 39.105 (2). The specific reference document for these modifications is De Havilland of Canada Service Bulletin No. 6/269. The Act imposes several obligations on the parties and entities it governs. Operators and owners of the affected DHC-6 aircraft are required to ensure that the modifications outlined in the Airworthiness Directive are completed within the stipulated timeframe. This includes conducting the necessary inspections, identifying any required modifications, and carrying out the modifications as per the specifications provided in the referenced Service Bulletin. Furthermore, operators must maintain records of compliance, as per section 39.105 (3), which may be subject to audits by the Civil Aviation Safety Authority (CASA) to ensure adherence to the regulations. Failure to comply with the requirements set forth in the Airworthiness Directive can result in significant consequences. Section 39.105 (4) stipulates that non-compliance with these airworthiness directives can be considered an offence under the Civil Aviation Act 1988. The penalties for such breaches may include substantial fines and, in severe cases, the grounding of the aircraft until the required modifications are completed. Additionally, operators may face civil actions for damages resulting from accidents or incidents caused by non-compliance. The maximum penalties, as outlined in the Act, can extend to fines of up to $165,000 for corporations and $33,000 for individuals, reflecting the seriousness of ensuring air safety. These provisions underscore the importance of strict adherence to airworthiness directives to maintain the highest safety standards in civil aviation.