AD/G159/42 - Electrical Power Distribution Protection

Overview

The Civil Aviation Orders, enacted by the Commonwealth of Australia in 1990, serve to regulate and ensure the safety of civil aviation within Australian airspace. One of the specific directives under these orders is the Airworthiness Directive AD/G159/42, which pertains to the Gulfstream (Grumman) G.159 series aeroplanes. This directive was introduced to address critical safety issues identified in the electrical power distribution system of these aircraft, particularly concerning the absence of adequate circuit protection for the APU generator output sensing wires and the insufficient protection for the inverter circuit. The objective of this directive is to enhance the electrical safety of the aircraft, thereby mitigating the risk of electrical faults that could compromise the aircraft's operation. The Civil Aviation Safety Authority, as the enforcing body, mandates compliance with these directives to ensure that all affected aircraft are serviced according to the specified requirements, thus maintaining the highest safety standards in civil aviation.

Scope and Application

The Civil Aviation Orders, specifically Part 105 Schedule of Airworthiness Directives under the Civil Aviation Safety Authority, pertain to the Gulfstream (Grumman) G.159 series aeroplanes. This legislation applies to all models within the specified series, mandating compliance with Gulfstream Mandatory Aircraft Service Change No 262. The directive requires action to be taken to ensure electrical power distribution protection, addressing specific vulnerabilities identified in the aircraft’s wiring and circuit protection systems. This applies to all serial numbers of the G1 model, where the APU generator output sensing wires lack circuit protection, and in some instances, the APU generator feeders themselves are also unprotected. The directive requires compliance before 26 January 1990, thereby ensuring that the identified faults are rectified to safeguard the aircraft's electrical systems. The legislation operates within the Commonwealth of Australia, overseen by the Civil Aviation Safety Authority, and its application is national, encompassing all relevant aircraft within the specified series across the country. There are no stated exclusions or exemptions within the text, and any further extension or restriction of application would be governed by subordinate instruments issued under the authority of the Civil Aviation Orders.

Key Provisions

The Civil Aviation Orders, specifically Part 105 Schedule of Airworthiness Directives, include an Airworthiness Directive (AD) for Gulfstream (Grumman) G.159 series aeroplanes, identified as AD/G159/42, which mandates electrical power distribution protection (section 1/89). This AD applies to all models of the Gulfstream G159 series aeroplanes and requires compliance with Gulfstream Mandatory Aircraft Service Change No 262. The directive necessitates that specific actions be taken to address identified issues with the electrical system's protection mechanisms, particularly those related to the APU (Auxiliary Power Unit) generator output sensing wires and the insufficient circuit protection within the inverter circuit. Under this directive, the primary requirement is to ensure that the APU generator output sensing wires are properly protected. This includes routing these wires from the APU to the generator over-voltage protector in a manner that provides the necessary circuit protection. Furthermore, the AD mandates that the APU generator feeders themselves must also be equipped with adequate circuit protection. This is crucial to prevent potential faults that could compromise the aircraft's electrical system. Compliance with these requirements must be achieved prior to 26 January 1990, as stipulated in the directive. The AD imposes several obligations on the parties involved, including aircraft operators and maintenance providers. These parties are required to thoroughly inspect the electrical systems of the affected Gulfstream G159 series aeroplanes to identify any deficiencies in the protection mechanisms. They must then implement the necessary modifications as outlined in Gulfstream Mandatory Aircraft Service Change No 262. This includes ensuring that the APU generator output sensing wires are routed correctly and that all APU generator feeders and inverter circuits are adequately protected. Failure to comply with these requirements could result in significant safety risks, as the lack of proper circuit protection could lead to electrical faults that might endanger the aircraft and its occupants. Failure to comply with the provisions of this Airworthiness Directive could result in serious consequences. The Civil Aviation Safety Authority (CASA) has the authority to enforce penalties for non-compliance. Depending on the severity of the breach, penalties may include fines, suspension or revocation of aircraft operating certificates, or other regulatory actions. The specific penalties are determined by CASA and can vary based on the nature and extent of the non-compliance. It is imperative for all parties governed by this directive to adhere to the requirements to avoid these potential consequences and ensure the continued airworthiness and safety of the Gulfstream G159 series aeroplanes.