AD/PC-12/14 - No. 2 Generator Cut-Out Relay

Overview

The Civil Aviation Regulations 1998, as amended, represent a cornerstone of Australia's aviation regulatory framework, ensuring the safety and efficiency of civil aviation. This legislation, enacted by the Commonwealth of Australia, is overseen by the Civil Aviation Safety Authority (CASA) and aims to maintain the highest standards of airworthiness and operational safety. One specific legislative instrument, F2006B06077, pertains to Pilatus PC-12 Series Aeroplanes and addresses an identified safety issue concerning the electrical system of these aircraft models. The Airworthiness Directive AD/PC-12/14, issued in response to reported incidents of over-voltage, mandates the installation of a cut-out relay in the electrical circuit of the second generator. This measure is designed to automatically disconnect the generator if a faulty condition is detected, thereby preventing potential system failures and enhancing overall flight safety. This directive underscores the commitment of Australian aviation authorities to proactively manage and mitigate risks associated with aircraft operations.

Scope and Application

The Civil Aviation Regulations 1998, specifically Part 39 - 105 and the Schedule of Airworthiness Directives, governs the maintenance and operational standards for civil aircraft within Australia, ensuring the safety and airworthiness of all aircraft. In the context of the Pilatus PC-12 series aeroplanes, Airworthiness Directive AD/PC-12/14 No. 2 mandates that for model PC-12 and PC-12/45 aeroplanes with Manufactures Serial Numbers 101 to 180 inclusive, a cut-out relay must be installed in the second generator electrical circuit if it has not already been done. This requirement is in response to reported instances of over-voltage where the over-voltage protection of the second generator did not automatically disconnect the generator from the electrical system, leading to potential safety risks. The directive mandates compliance by 30 April 1999, with the directive becoming effective from 25 February 1999. The directive references FOCA Switzerland AD HB 98-537, indicating alignment with international safety standards. This directive applies to specific aircraft models and serial numbers, underscoring the targeted approach to enhancing airworthiness through precise regulatory action.

Key Provisions

The main operative sections of the Civil Aviation Regulations 1998 (Pilatus PC-12 Series Aeroplanes) include sections that specify the applicability, requirements, and compliance timelines of the Airworthiness Directive (AD) AD/PC-12/14. Specifically, section 39-105 of the Regulations mandates that the directive applies to Pilatus PC-12 and PC-12/45 aeroplanes with Manufactures Serial Numbers 101 to 180 inclusive (section 39-105(1)). The requirement set out in this section is that a cut-out relay must be installed in the second generator electrical circuit if it has not already been done (section 39-105(2)). This installation must follow the instructions in Pilatus Aircraft Ltd Service Bulletin 24-009 dated 23 September 1998, and the compliance deadline for these actions is before 30 April 1999 (section 39-105(3)). The directive became effective on 25 February 1999 (section 39-105(4)). The obligations imposed by this Airworthiness Directive on the relevant parties include ensuring that the specified Pilatus PC-12 and PC-12/45 aeroplanes are modified to meet the directive’s requirements. Specifically, operators of these aircraft must arrange for the installation of a cut-out relay in the second generator electrical circuit. This involves following the detailed instructions provided in the referenced service bulletin from Pilatus Aircraft Ltd. Additionally, compliance must be achieved by the stipulated deadline to maintain the airworthiness of the aircraft. Failure to comply with the requirements of this Airworthiness Directive can result in severe consequences. Although specific penalties are not detailed within the directive, non-compliance with airworthiness directives typically results in enforcement actions by the Civil Aviation Safety Authority (CASA). Potential consequences may include grounding of the aircraft, fines, or other regulatory sanctions. Furthermore, failure to adhere to airworthiness directives can also lead to criminal charges if the non-compliance results in safety incidents or accidents. Such incidents may lead to significant penalties, including imprisonment for the responsible individuals or entities, depending on the severity of the breach and its impact on aviation safety.