AD/AS 355/14 Amdt 1 - Combiner Gearbox R.H. and L.H.

Overview

The Civil Aviation Regulations 1998, specifically Part 39 - 105 of the Civil Aviation Safety Authority's Schedule of Airworthiness Directives, addresses the safety concerns related to the Eurocopter AS 355 (Twin Ecureuil) Series Helicopters. Enacted by the Commonwealth of Australia, this legislation targets the issue of deep wear on the combiner gearbox input flanges due to contact between the engine coupling shaft and the input flanges. The policy objective is to ensure the continued airworthiness and safety of these aircraft by mandating specific maintenance actions. The directive requires compliance with Aerospatiale SB 05-09 Revision 2, stipulating timeframes for inspections and actions based on the accumulated service hours of the main gearbox, ensuring that these critical components are maintained to prevent potential failures. This legislative instrument was introduced to mitigate the risk of mechanical failures that could compromise flight safety, thereby protecting both the operators and the passengers of these aircraft. The directive underscores the importance of adhering to the manufacturer's service bulletins and maintaining rigorous oversight of the maintenance schedules for these helicopters.

Scope and Application

The Civil Aviation Regulations 1998, specifically under Part 39 - 105, mandates Airworthiness Directives concerning the Eurocopter AS 355 (Twin Ecureuil) Series Helicopters. This legislation applies to all model AS355 aircraft fitted with input flanges P/No 355A32-2095-20 and 21 on which either modification AMS 350A07-9527 or AMS 350A07-9534 has not been embodied. The directive is issued by the Civil Aviation Safety Authority and is intended to address safety concerns arising from deep wear on the combiner gearbox input flanges. The geographic reach of this Act is national, applying across the Commonwealth of Australia. The directive does not specify any exclusions or exemptions but mandates specific actions to be taken in accordance with Aerospatiale Service Bulletin 05-09 Revision 2, thereby ensuring the maintenance and safety standards of these aircraft. Compliance with the directive is contingent on the service hours of the main gearbox, requiring actions at various stages of service hours to mitigate potential risks.

Key Provisions

The Civil Aviation Regulations 1998, specifically Part 39 - 105, contain detailed directives concerning the airworthiness of aircraft, with particular focus on the Eurocopter AS 355 (Twin Ecureuil) series helicopters. One such directive, AD/AS 355/14 Amendment 1, pertains to the combiner gearbox R.H. and L.H. of these helicopters, particularly those fitted with input flanges P/No 355A32-2095-20 and 21, unless certain modifications have been implemented (Section 105.01). This directive necessitates compliance with Aerospatiale Service Bulletin 05-09 Revision 2 to address issues of deep wear on the combiner gearbox input flanges. The directive imposes specific timelines and operational hour requirements on the aircraft owners or operators. For aircraft whose main gearbox has accumulated 250 or more hours of service, compliance must be achieved within the next 50 hours of service following 19 May 1988, or by 30 September 1988, whichever is earlier (Section 105.02). For those helicopters with less than 250 hours on the main gearbox, compliance must be achieved before the gearbox reaches 300 hours of service. Thereafter, compliance must be maintained at intervals not exceeding 300 hours of service (Section 105.03). Failure to comply with the provisions of AD/AS 355/14 Amendment 1 may result in significant consequences. Non-compliance with airworthiness directives is considered a serious breach of safety regulations, potentially leading to civil or criminal penalties (Section 105.04). Civil penalties may include fines or other financial penalties, while criminal penalties can include imprisonment, depending on the severity and intent behind the non-compliance. It is critical for aircraft operators to adhere to these directives to ensure the safety and airworthiness of their aircraft, thereby avoiding these adverse legal and financial repercussions.