AD/ENST 28/37 - Voltage Regulator

Overview

The Civil Aviation Regulations 1998, administered by the Civil Aviation Safety Authority, were enacted to ensure that aviation operations in Australia meet high safety standards. A specific legislative instrument under this Act, F2006B09594, addresses issues relating to the airworthiness of Enstrom F-28 Series Helicopters, particularly focusing on the voltage regulator and over-voltage relay systems. This directive was introduced to prevent potential electrical overloads that could lead to inflight fires and forced landings. The policy objective of this directive is to enhance the safety of civil aviation by ensuring the proper functioning of critical electrical components in these helicopters. Compliance with the directive involves specific checks and modifications to the voltage regulator and over-voltage relay systems, with certain actions required within specific timeframes after the directive's effective date.

Scope and Application

The Civil Aviation Regulations 1998, specifically Part 39 - 105, which pertains to the Civil Aviation Safety Authority's schedule of airworthiness directives, applies to the Enstrom F-28 Series helicopters, including models F-28A, 280, F-28C with a serial number less than S/N 745, and Model 280C helicopters with a serial number less than S/N 1502. This regulation is applicable on a national level, overseen by the Commonwealth of Australia, and it governs the airworthiness and operational safety of these helicopter models. The directive outlines specific requirements to be fulfilled by operators or owners of these aircraft to ensure they meet safety standards, particularly concerning the helicopter's voltage regulator and over-voltage relay systems. Compliance with these directives is mandatory and involves a series of checks and modifications to prevent potential electrical failures that could lead to inflight fires and forced landings. The directive stipulates different timelines for compliance based on the specific actions required, such as adjustments within 5 hours of the directive's effective date or modifications before the next flight.

Key Provisions

The Civil Aviation Regulations 1998, specifically under PART 39 - 105, mandate that certain Enstrom F-28 Series Helicopters comply with Airworthiness Directive (AD) 97-20-04, which concerns the voltage regulator and over-voltage relay of these aircraft (section 1). The directive applies to specific models and serial numbers, particularly those equipped with a Prestolite-manufactured voltage regulator or over-voltage relay (section 1). The main requirement is to determine if the specified parts are installed and to ensure the alternator output voltage is within the correct range (section 1.a). If any issues are found, the voltage regulator must be adjusted or replaced, and the over-voltage relay must be tested and replaced if necessary (section 1.a). If no over-voltage relay is installed, one must be added, or a transistorised voltage controller must be installed and the wiring modified (section 1.b). The amp meter must also be checked for normal readings while the engine is operating at 2,200 RPM (section 1.c). The AD imposes specific obligations on the operators of these helicopters. Operators must ensure that the voltage regulator and over-voltage relay are installed and functioning correctly (section 1). If the specified components are present, they must be tested and adjusted or replaced as necessary within 5 hours of the AD becoming effective (section 1). Operators must also ensure that any missing over-voltage relays are installed or that the appropriate voltage controller is fitted before the next flight (section 1). Furthermore, operators must conduct further checks on the voltage regulator and over-voltage relay at each annual inspection or every 100 hours of operation, whichever comes first (section 1). These checks must be conducted in accordance with the instructions provided in the Enstrom Helicopter Corporation Service Directive Bulletin (SDB) No. 0086, dated 31 March 1996 (section 1). Failure to comply with this airworthiness directive can result in serious safety hazards, including electrical overloads, voltage regulator and over-voltage relay failures, inflight fires, and forced landings (section 1). While the Civil Aviation Regulations 1998 do not explicitly state penalties for non-compliance with this AD, general regulations under the Civil Aviation Act 1988 provide for penalties for non-compliance with airworthiness directives. These penalties can include fines of up to $22,222 and/or imprisonment for up to two years for individuals, and higher fines for corporations. Additionally, non-compliance could lead to the grounding of the affected aircraft, which would prevent the operator from using the helicopter until compliance is achieved, resulting in potential financial loss and operational disruptions.