AD/GAF-N22/43 Amdt 1 - Autopilot Aileron Servo Unit Bridle Cable Assembly P/N 1/N-45-1317 - Inspection

Overview

The Civil Aviation Regulations 1998, enacted by the Commonwealth of Australia, were established to ensure the safety and regulation of civil aviation within Australia. Among the various parts and schedules that comprise these regulations, Part 39 - 105, which pertains to the Civil Aviation Safety Authority Schedule of Airworthiness Directives, plays a crucial role. This part specifically addresses the safety and airworthiness of certain aircraft types, including the GAF N22 and N24 series aeroplanes. The problem this legislation was introduced to address is the in-flight failure of the autopilot aileron servo bridle cable, which can severely restrict aileron control movement and thus compromise flight safety. The policy objective is to mandate regular inspections of the specified cable assemblies to mitigate such risks, ensuring the continued safety of aircraft operations within Australia.

Scope and Application

The Civil Aviation Regulations 1998, under Part 39 - 105, pertains specifically to the Civil Aviation Safety Authority's Schedule of Airworthiness Directives for GAF N22 and N24 series aeroplanes. This regulation applies to all models N22, N22B, N22S, N24, and N24A equipped with a 2-axis autopilot, specifically those identified as options G48, G48-24, and G48-22S, excluding those modified to Mod. N554 or SB NMD-27-22. The geographic reach of this regulation is national, applying across all states and territories within Australia, and it is enforced by the Civil Aviation Safety Authority, a federal body. The directive mandates an initial inspection of the autopilot aileron servo bridle cable assembly within 10 hours of service after 11 September 1981, and subsequent inspections must not exceed intervals of 120 hours of service. This requirement stems from incidents where the autopilot aileron servo bridle cable has failed in flight, leading to restricted aileron control movement, as documented in GAF Alert SB No. ANMD-27-20. The regulation’s application may be further defined or extended through subordinate instruments issued by the Civil Aviation Safety Authority.

Key Provisions

The Civil Aviation Regulations 1998, particularly Part 39 - 105, include a schedule of airworthiness directives that are imperative for ensuring the safety and compliance of aircraft within Australia. One such directive, AD/GAF-N22/43 Amendment 1, concerns the inspection of the autopilot aileron servo unit bridle cable assembly for GAF N22 and N24 series aeroplanes (section 1). This directive applies specifically to all models N22, N22B, N22S, N24, and N24A that are equipped with a 2-axis autopilot (options G48, G48-24, and G48-22S), with the exception of those modified to Model N554 or Service Bulletin NMD-27-22 (section 2). Compliance with this directive necessitates that the autopilot aileron servo unit bridle cable assembly, identified by Part Number 1/N-45-1317, be inspected under specific conditions (section 3). The initial inspection must occur within 10 hours of the aeroplane's time in service after 11 September 1981. Following this initial inspection, further inspections must be conducted at intervals not exceeding 120 hours of time in service (section 4). This directive was issued due to an in-flight failure of the autopilot aileron servo bridle cable on a local aeroplane, which led to restricted aileron control movement, as detailed in GAF Alert Service Bulletin No. ANMD-27-20 (section 5). The obligations imposed by this airworthiness directive are clear and must be adhered to by the operators of the specified aircraft models. Operators are required to ensure that the specified inspection is conducted in a timely and regular manner, as stipulated by the directive (section 6). Failure to comply with the inspection intervals or to conduct the inspection at all could result in serious safety implications and potential non-compliance with the Civil Aviation Regulations (section 7). The directive also specifies that certain modifications, such as Model N554 or Service Bulletin NMD-27-22, exempt the aeroplane from the requirement to inspect the autopilot aileron servo unit bridle cable (section 8). Should an operator fail to comply with the provisions of this airworthiness directive, there could be significant consequences. Non-compliance may result in the aircraft being deemed unairworthy, which could lead to grounding of the aeroplane until the necessary inspections are conducted (section 9). Additionally, there may be enforcement actions taken by the Civil Aviation Safety Authority, which could include fines or other penalties as prescribed by the Civil Aviation Act 1988 or other relevant legislation (section 10). The exact nature and severity of these penalties would be determined by the specific circumstances of the breach and the applicable legal framework.