AD/TB20/20 - Horizontal Stabiliser Balance Weight

Overview

The Civil Aviation Regulations 1998, specifically Part 39, were enacted to ensure safety in the operation of civil aircraft in Australia, addressing gaps in aviation safety standards and regulations. Among these provisions, the Civil Aviation Safety Authority Schedule of Airworthiness Directives includes AD/TB20/20, which pertains to the Aerospatiale (Socata) TB20 (Trinidad) Series Aeroplanes. This directive was introduced to rectify safety issues identified in certain models of these aircraft. The Civil Aviation Safety Authority, under the authority granted by the Civil Aviation Act 1988, mandates the compliance with this directive to prevent dangerous conditions, such as the detachment of the horizontal stabilizer balance weight, which could lead to severe safety hazards. The policy objective is to ensure that these aircraft meet necessary safety standards, thereby safeguarding the public and maintaining the integrity of the civil aviation system.

Scope and Application

The Civil Aviation Regulations 1998, as amended, under the authority of the Civil Aviation Safety Authority, include specific Airworthiness Directives that govern the operational safety of aircraft within Australia. One such directive, AD/TB20/20, pertains to the Aerospatiale (Socata) TB20 (Trinidad) Series Aeroplanes, specifically those with model numbers TB20 and TB21 and serial numbers ranging from 1 to 1030. This directive mandates that an inspection be conducted to ascertain whether the attaching nuts of the horizontal stabilizer balance weight are within the prescribed safety dimensions. Failure to adhere to this directive may result in a dangerous flutter condition, thereby necessitating compliance within 25 hours of time in service after 13 February 1991. This directive underscores the importance of stringent safety protocols in ensuring the continued airworthiness of these aircraft models. The directive applies specifically to the aforementioned Aerospatiale (Socata) TB20 (Trinidad) Series Aeroplanes operating within the jurisdiction of the Commonwealth of Australia. It does not explicitly extend to other aircraft models or series, nor does it cover other types of aviation activities outside the scope of these specific models. The directive’s geographic reach is confined to the national airspace of Australia, enforcing compliance through the Civil Aviation Safety Authority. This directive does not specify any exclusions, exemptions, or thresholds beyond the parameters of the aircraft model and serial numbers indicated. The requirement to comply with Alert SB 57 further ensures that any actions taken are in line with broader safety communications issued by the relevant authorities.

Key Provisions

The Civil Aviation Regulations 1998, specifically Part 39 - 105, mandate certain airworthiness directives for aircraft types, including the Aerospatiale (Socata) TB20 (Trinidad) Series Aeroplanes. Among these directives is AD/TB20/20, which addresses the horizontal stabilizer balance weight (section 4/91 DM). This directive applies to all TB20 and TB21 series aircraft with serial numbers ranging from 1 through 1030. The primary requirement under this directive is to conduct an inspection to verify that both attaching nuts of the horizontal stabilizer balance weight are within the specified safety dimensions as outlined in Alert SB 57. The directive stipulates that this inspection must be carried out within 25 hours of time in service after 13 February 1991. The rationale behind this requirement is to prevent any potential dangerous flutter conditions that could arise from the detachment of the balance weight. In terms of obligations, the Civil Aviation Regulations impose a clear responsibility on the operators of the specified aircraft models to ensure compliance with AD/TB20/20. This involves conducting a thorough inspection as required and taking necessary corrective actions if any issues are identified. The inspection must be meticulously documented, and records must be maintained for a period as stipulated by the Civil Aviation Safety Authority (CASA). Operators must also ensure that the inspection is performed by qualified personnel who are knowledgeable about the specific requirements of the AD/TB20/20 directive. Failure to comply with the provisions of AD/TB20/20 can result in significant consequences. Under the Civil Aviation Act 1988, non-compliance with an airworthiness directive can lead to enforcement actions by CASA. The potential penalties for breaching these regulations can include fines and other civil or criminal penalties. The exact nature and severity of these penalties are determined by CASA, but the potential for significant financial repercussions underscores the importance of strict adherence to the directive. In severe cases, continued non-compliance may also result in the grounding of the aircraft, which can have substantial operational and financial impacts on the operator.