AD/DHC-6/11 - Flap Elevator Trim Cables - Modification

Overview

The Civil Aviation Regulations 1998, enacted by the Australian Parliament, form a comprehensive framework governing aviation safety and operations within Australia. A specific part of this legislation, Part 39 - 105, addresses the Civil Aviation Safety Authority’s Schedule of Airworthiness Directives. One such directive, AD/DHC-6/11, pertains to the modification of flap elevator trim cables for the DHC-6 (Twin Otter) Series Aeroplanes. This directive was introduced to address safety concerns related to the integrity of flap elevator trim cables, ensuring that all affected models with serial numbers from 1 to 95 comply with the specified modifications within 300 hours of time in service after the directive was issued on 21 March 1968. The policy objective is to enhance the safety and reliability of these aircraft by mitigating risks associated with cable failures.

Scope and Application

The Civil Aviation Regulations 1998, specifically Part 39 - 105, pertains to the Civil Aviation Safety Authority’s Schedule of Airworthiness Directives for DHC-6 (Twin Otter) Series Aeroplanes. This particular legislation applies to all models of the DHC-6 Twin Otter aircraft with serial numbers ranging from 1 to 95, mandating modifications to the flap elevator trim cables as outlined in De Havilland of Canada Modification Bulletin No. 6/1127. Compliance with this directive is mandatory within 300 hours of time in service after the directive’s issuance date of 21 March 1968. The directive's geographic reach is national, applying uniformly across Australia, and is enforced by the Civil Aviation Safety Authority, a Commonwealth entity. There are no stated exclusions, exemptions, or thresholds in this directive, meaning all applicable aircraft must adhere to the specified modifications to ensure continued airworthiness. The Act may also extend or restrict application through subordinate instruments, which would provide further detail and operational guidelines for compliance.

Key Provisions

The Civil Aviation Regulations 1998, Part 39, specifically the Schedule of Airworthiness Directives (AD/DHC-6/11), pertains to De Havilland Canada DHC-6 (Twin Otter) Series aeroplanes and addresses modifications to the flap elevator trim cables. Section 2 of this directive applies to all models with serial numbers ranging from 1 to 95. The requirement outlined in this section is for compliance with the modifications as detailed in the De Havilland of Canada Modification Bulletin No. 6/1127. This compliance must be achieved within 300 hours of the aeroplane's time in service following the directive's effective date of 21 March 1968. The obligations imposed by this directive are clear and straightforward. Aircraft operators and owners must ensure that the specified modifications to the flap elevator trim cables are carried out as per the instructions provided in the referenced modification bulletin. This involves following the detailed steps and procedures outlined to ensure the aeroplane remains compliant with airworthiness standards. The modifications are crucial for maintaining the structural integrity and safe operation of the aeroplane, thus ensuring that the aircraft meets the necessary safety standards set by the Civil Aviation Safety Authority. Breaching the requirements set out in this directive can lead to significant consequences. The Civil Aviation Regulations 1998 establish that failure to comply with an Airworthiness Directive can result in the aircraft being considered unairworthy. This can lead to enforcement actions by the Civil Aviation Safety Authority, including potential grounding of the aircraft. Additionally, operators may face penalties, including fines, and in severe cases, criminal charges could be pursued. The exact penalties are determined by the nature and severity of the breach, but they can include substantial fines and imprisonment, underscoring the importance of strict adherence to these directives.