AD/BELL 412/38 - Hydraulic Servo Actuator Shoulder Bolt

Overview

The Civil Aviation Regulations 1998, enacted by the Parliament of the Commonwealth of Australia, govern the safety and operational standards within Australia's civil aviation sector. One particular legislative instrument under these regulations, F2006B04672, addresses the specific issue of the airworthiness of Bell Helicopter Textron 412 Series Helicopters. The problem it was introduced to address involves the potential for unauthorised rework or repair of the hydraulic servo actuator shoulder bolts on certain Bell 412 series helicopters, which could compromise the safety of these aircraft. The policy objective of this instrument is to ensure that these helicopters maintain their airworthiness standards by requiring inspections and necessary corrective actions on the specified shoulder bolts. This legislative instrument is part of a broader effort to maintain and enhance the safety of civil aviation through precise regulatory oversight. By mandating inspections and actions for specific helicopter models with potentially compromised shoulder bolts, it seeks to prevent safety issues that might arise from unapproved repairs or rework. The requirement for compliance within a defined timeframe underscores the urgency and importance of addressing these potential safety hazards.

Scope and Application

The Civil Aviation Regulations 1998, as amended, specifically under Part 39 - 105, address the safety directives applicable to the Bell Helicopter Textron 412 Series Helicopters. These regulations apply to certain serial numbers of these helicopters, particularly those with hydraulic servo actuator shoulder bolts that have been overhauled or repaired by non-approved facilities. The scope of this particular directive, AD/BELL 412/38, mandates a comprehensive inspection of the shoulder bolts for potential unauthorised chrome plating, a safety concern identified by Bell Textron. The directive applies to helicopters with specific serial numbers and requires compliance with Bell ASB 412-95-86, ensuring that the inspection and necessary actions are completed within 25 hours of the helicopter's time in service from 7 December 1995 or by 31 January 1996, whichever comes first. This legislation underscores the importance of adhering to approved maintenance practices to uphold aviation safety standards. The geographic and jurisdictional reach of these regulations is national, extending throughout the Commonwealth of Australia, ensuring uniform compliance with safety directives across the country. While the primary focus is on specific serial numbers of Bell Helicopter Textron 412 Series Helicopters, the implications are broad, impacting operators, maintenance facilities, and aviation safety authorities within Australia. The directive does not explicitly mention exclusions or exemptions, but its applicability is clearly defined by the serial numbers and maintenance history of the helicopters in question. Furthermore, the authority to enforce these regulations and to issue further subordinate instruments or amendments is vested in the Civil Aviation Safety Authority, allowing for flexibility and responsiveness to evolving safety concerns.

Key Provisions

The Civil Aviation Regulations 1998, specifically Part 39 - 105, under the Civil Aviation Safety Authority's schedule of airworthiness directives, includes an important directive concerning the Bell Helicopter Textron 412 Series Helicopters. This directive, AD/BELL 412/38, pertains to the hydraulic servo actuator shoulder bolt and is numbered 13/95. This directive applies to all Bell Helicopter Textron 412 Series Helicopters with specific serial numbers, namely S/N 33001 through 33213, 36001 through 36104, 34001 through 34024, and 46400 through 46408, provided they have servos that have been overhauled or repaired by a facility not approved by HR Textron (s. 1). The directive mandates that unless previously carried out, action in accordance with Bell ASB 412-95-86 must be undertaken. Compliance with this directive is required within 25 hours of time in service from 7 December 1995, or by 31 January 1996, whichever occurs first (s. 2). Operators and owners of the affected helicopters are obligated to ensure that the required actions are taken in accordance with the specified directive. This involves inspecting the shoulder bolts for any unauthorised chrome plating, which may have occurred due to unauthorised rework or repairs. These inspections must be carried out diligently to maintain the safety and airworthiness of the aircraft. Failure to comply with this directive can result in the aircraft being deemed unairworthy, which could lead to operational restrictions or grounding of the helicopter (s. 3). The directive is clear and unequivocal, leaving no room for non-compliance without significant safety implications. In the event of non-compliance with the directive, there are potential legal and safety consequences. The Civil Aviation Safety Authority (CASA) may take enforcement action against operators or owners who fail to adhere to the requirements. This could include fines, suspension or revocation of airworthiness certificates, and other administrative penalties. The seriousness of non-compliance is underscored by the potential for significant safety risks, as unauthorised alterations to critical components such as the hydraulic servo actuator shoulder bolts could compromise the integrity and safety of the aircraft (s. 4). Therefore, it is imperative that all stakeholders involved with the affected helicopters take the directive seriously and ensure full compliance.