AD/HILLER 12/26 - Rotor Tachometer Generator - Replacement

Overview

The Civil Aviation Regulations 1998, specifically under Part 39 - 105, address the safety and operational standards for civil aviation in Australia. One such regulation, AD/HILLER 12/26, pertains to the replacement of rotor tachometer generators in Hiller UH-12 Series Helicopters, particularly the UH-12D and UH-12E models with Soloy Turbine Conversions. This Airworthiness Directive was introduced to mitigate the risks associated with the existing tachometer generators, which had been experiencing frequent failures leading to false low rotor speed warnings and subsequent emergency procedures, potentially compromising safety. The objective of this directive is to replace the existing tachometer generators with a new type that is expected to reduce such failures and enhance the overall safety of the aircraft by avoiding unnecessary hazards. Enacted by the Civil Aviation Safety Authority, this directive aims to ensure compliance within 200 hours of time in service after the specified date of 31 May 1979, as referenced in the Soloy Conversions SB 03-560 and the FAA AD 79-03-07. The policy objective is clear: to enhance the reliability and safety of rotor tachometer generators, thereby reducing the likelihood of operational hazards during flight.

Scope and Application

The Civil Aviation Regulations 1998, specifically Part 39 - 105, applies to all operators of Hiller UH-12D and UH-12E helicopters that have undergone Soloy Turbine Conversion and are equipped with 22A580 tachometer generators in the rotors' position. This regulation mandates compliance with Airworthiness Directives (AD) that have been issued to address safety concerns related to the rotor tachometer generator. The geographic reach of this regulation is national, applying across the Commonwealth of Australia. The directive requires compliance within 200 hours’ time in service after 31 May 1979, as specified in Soloy Conversions Service Bulletin 03-560 or Federal Aviation Administration AD 79-03-07. The aim is to replace the existing tachometer generators to mitigate hazards such as unnecessary external load deployment and full autorotation following false low rotor speed warning system activation. While the Act itself outlines the primary requirements, its application and enforcement may be extended or detailed through subordinate instruments issued by the Civil Aviation Safety Authority.

Key Provisions

The Civil Aviation Regulations 1998, specifically Part 39 - 105, mandates that certain models of helicopters must adhere to Airworthiness Directives (AD) issued by the Civil Aviation Safety Authority (CASA). The directive AD/HILLER 12/26 pertains to Hiller UH-12 Series Helicopters, more precisely models UH-12D and UH-12E helicopters equipped with Soloy Turbine Conversion using 22A580 tachometer generators in the rotors' position. The directive requires these helicopters to replace their rotor tachometer generators within 200 hours’ time in service after 31 May 1979 (Section 39 - 105). Compliance with this directive is to be achieved by referencing either Soloy Conversions Service Bulletin 03-560 or the Federal Aviation Administration (FAA) AD 79-03-07. The directive aims to mitigate the risk of false low rotor speed warning system activations, which can lead to unnecessary emergency procedures and potential hazards. The obligations imposed by AD/HILLER 12/26 on helicopter operators include ensuring that the rotor tachometer generators of their UH-12D and UH-12E helicopters are replaced within the stipulated timeframe. This involves closely monitoring the operational hours of the affected helicopters and scheduling the necessary maintenance actions promptly. Operators must keep detailed records of all compliance activities and maintain these records for a period specified by CASA. Additionally, the directive necessitates that all maintenance and replacement work is performed by qualified personnel who are authorised to work on such aircraft systems. Failure to comply with AD/HILLER 12/26 can lead to significant legal and safety consequences. Civil penalties may be imposed, including fines and potential enforcement actions by CASA. In severe cases, non-compliance could result in the grounding of the affected helicopters until the required maintenance is completed. Furthermore, continued operation of a helicopter that does not comply with the directive could pose a serious risk to flight safety, potentially leading to criminal charges for those responsible for the oversight or operation of the aircraft. The specific penalties and consequences are outlined in the Civil Aviation Regulations 1998 and can include substantial fines and imprisonment for individuals found guilty of violations.