AD/DHC-6/63 - Gust Lock Assembly

Overview

The Civil Aviation Regulations 1998, enacted by the Australian Parliament, provide a comprehensive framework for the safety of civil aviation within Australia. Part 39, in particular, addresses Airworthiness Directives (ADs) to ensure aircraft remain in a condition for safe operation. One such AD, AD/DHC-6/63, targets the DHC-6 (Twin Otter) Series Aeroplanes, specifically addressing the Gust Lock Assembly. This directive was introduced to address safety concerns related to instances where aircraft took off with pre-modification 6/1676 gust locks still engaged. The policy objective is to mandate compliance with Boeing Canada Service Bulletin 6/508 to prevent such occurrences, ensuring the safety and reliability of the aircraft in operation. This particular AD was issued to rectify a safety gap identified in the DHC-6 (Twin Otter) Series Aeroplanes, where improper engagement of gust locks led to unsafe flight conditions. By requiring compliance with the Boeing Canada Service Bulletin 6/508, the AD aims to mitigate the risk of accidents caused by such mechanical failures. The directive applies to specific serial numbers of the Twin Otter aircraft, demanding action to be taken before 31 July 1990. This legislative measure underscores the Civil Aviation Safety Authority's commitment to maintaining stringent safety standards within the aviation sector.

Scope and Application

The Civil Aviation Regulations 1998, specifically Part 39 - 105, applies to the maintenance and operation of DHC-6 (Twin Otter) Series Aeroplanes within the Commonwealth of Australia. The regulations pertain to the safety directive concerning the gust lock assembly, targeting serial numbers 1 to 690, 692, 693, 695, and 696. The directive mandates that operators and maintainers comply with Boeing Canada Service Bulletin 6/508 to rectify the gust lock assembly, referencing Canadian Airworthiness Directive CF-90-01. This directive requires compliance by 31 July 1990, reflecting the urgency and necessity to address safety concerns identified in three reported incidents where aircraft took off with pre-modification 6/1676 gust locks still engaged. The regulation’s jurisdictional reach is national, ensuring all operators within Australia adhere to these safety standards to mitigate risks associated with improper gust lock engagement.

Key Provisions

The Civil Aviation Regulations 1998, specifically Part 39 - 105, contain the Civil Aviation Safety Authority's (CASA) Schedule of Airworthiness Directives for DHC-6 (Twin Otter) Series Aeroplanes. One such directive, AD/DHC-6/63, pertains to the gust lock assembly, as outlined in Boeing Canada Service Bulletin 6/508. This directive applies to aircraft with serial numbers 1 to 690, 692, 693, 695, and 696. The directive requires action in accordance with the specified service bulletin, referencing Canadian Airworthiness Directive CF-90-01. Notably, compliance with this directive must be achieved before 31 July 1990, as it addresses reported instances where aircraft took off with pre-modification 6/1676 gust locks still engaged. The main obligation imposed by AD/DHC-6/63 is the requirement for the aircraft operators to ensure the gust lock assembly is properly configured in line with Boeing Canada Service Bulletin 6/508. This involves making necessary modifications to the gust lock assembly to prevent it from being engaged during take-off, a critical safety measure to avoid potential flight control issues. Operators must also ensure that all relevant personnel are adequately trained on the modifications and that all aircraft meet the compliance deadline of 31 July 1990. The directive underscores the importance of maintaining accurate records and documentation of the modifications and compliance status. Failure to comply with AD/DHC-6/63 may result in serious civil and criminal consequences. Under the Civil Aviation Act 1988, non-compliance with airworthiness directives can lead to enforcement actions by CASA. Civil penalties can include substantial fines, and criminal charges may be brought against the responsible individuals. Specifically, CASA has the authority to impose fines of up to $275,000 for each instance of non-compliance. Additionally, individuals found guilty of violating these regulations may face imprisonment for up to two years. Such stringent measures underscore the importance of adhering to the directive to ensure the safety of flight operations.