AD/PA-31/15 - Alternator Field Fuse - Installation

Overview

The Civil Aviation Regulations 1998, enacted by the Parliament of the Commonwealth of Australia, provide a comprehensive regulatory framework for civil aviation within Australia, including the establishment of safety standards. Specifically, Part 39 - 105 Civil Aviation Safety Authority Schedule of Airworthiness Directives focuses on maintaining the airworthiness of aircraft through specific directives. This legislative instrument addresses gaps in aircraft safety and maintenance protocols to ensure the safe operation of aircraft. The policy objective of these regulations is to mandate specific safety measures and compliance timelines, thereby enhancing overall aviation safety. One such directive is AD/PA-31/15, which pertains to the installation of an alternator field fuse in Piper PA-31 Series aeroplanes. This directive was introduced to mitigate risks associated with alternator field circuits, which can cause damage or failure if not properly fused. By requiring the installation of a 3 amp fuse in certain field circuits, the regulation aims to prevent electrical faults that could compromise the safety of the aircraft. Compliance with this directive is required within 200 hours of time in service after 31 March 1971, ensuring that the necessary safety measures are implemented promptly.

Scope and Application

The Civil Aviation Safety Authority Schedule of Airworthiness Directives (AD/PA-31/15) applies to all Piper PA-31 series aeroplanes fitted with a voltage regulator selector switch. This directive is intended to ensure the safety of the aircraft by mandating specific modifications to the alternator field fuse installations in these models. The directive applies to both commercial and private operators of these aircraft within the Commonwealth of Australia, enforcing safety standards across the aviation industry. The directive does not specify any exclusions or exemptions, meaning that all applicable aircraft must comply with the requirements outlined. Subordinate instruments may extend or restrict the application of this directive, but as per the given text, no such details are provided. Compliance is required within 200 hours of time in service after 31 March 1971, ensuring that the modifications are implemented promptly to maintain safety standards.

Key Provisions

The Civil Aviation Regulations 1998, specifically Part 39 - 105, contain provisions that mandate certain safety measures for Piper PA-31 series aeroplanes. Among these is Airworthiness Directive AD/PA-31/15, which pertains to the installation of alternator field fuses. Section 1 of this directive outlines the requirement to install a 3 amp fuse in specific field circuits of the aircraft. For PA-31 models equipped with a Delco Remy 50 amp alternator system, the fuse must be installed between the “F” field terminal on the alternator and the alternator main circuit breaker (section 1(a)). For those with a Prestolite 70 amp alternator system, the fuse must be placed between the “F” field terminal and the junction point of cables PF34EF and PF33EE inboard of the wing root terminal strips (section 1(b)). Additionally, PA-31P aircraft must have a 3 amp fuse in each field circuit between the voltage regulator selector switch and the alternator control switches (section 1(c)). After installation, the functionality of the alternator system and the adjustment of the voltage regulators must be checked as per the manufacturer’s service manual (section 1(d)). Under the Civil Aviation Regulations, compliance with Airworthiness Directive AD/PA-31/15 is mandatory for all Piper PA-31 series aircraft. Operators and owners of these aircraft must ensure that the specified fuses are installed within 200 hours of time in service after 31 March 1971. This requirement ensures the safety and reliability of the aircraft’s electrical systems by mitigating the risks associated with potential field circuit failures. The installation must be carried out according to the detailed instructions provided in section 1 of the directive, and any subsequent functional checks must adhere to the manufacturer's service manual specifications. Failure to comply with the requirements set out in Airworthiness Directive AD/PA-31/15 may result in serious safety implications, potentially leading to electrical failures during flight. The Civil Aviation Regulations impose strict obligations on aircraft operators and owners to ensure that these safety measures are implemented. Non-compliance with these provisions can lead to significant civil and criminal consequences, including fines and potential grounding of the aircraft until the necessary modifications are made. The specific penalties for breaches of these regulations are not detailed in the provided text, but they can typically include substantial monetary fines and other regulatory sanctions. It is therefore imperative for operators to adhere to these directives to maintain airworthiness and ensure the safety of all persons on board.