AD/HILLER 12/30 Amdt 2 - Main Rotor Assembly

Overview

The Civil Aviation Regulations 1998, enacted by the Commonwealth of Australia, encompass various safety regulations for aviation, including the Airworthiness Directives (ADs). This legislative instrument, specifically AD/HILLER 12/30 Amendment 2, was introduced to address issues concerning the main rotor blade spars of certain Hiller UH-12 series helicopters, which are prone to developing bond separation and voids that could lead to spar cracking. The objective is to enhance the safety of these aircraft by implementing stringent inspection and maintenance requirements. Compliance with these directives is mandated to ensure the continued airworthiness of affected helicopters, overseen by the Civil Aviation Safety Authority. The policy objective is clearly to mitigate risks associated with structural failures in the main rotor blades, thereby safeguarding the integrity of the aircraft and the safety of its occupants.

Scope and Application

The Civil Aviation Regulations 1998, specifically Part 39 - 105, applies to the maintenance and safety standards of Hiller UH-12 series helicopters, including all models such as UH-12D, UH-12E, UH-12E4, OH-23F, OH-23G, and those converted by STC SH 178WE and STC SH 177 WE, provided they are equipped with the main rotor blades assembly Parsons P/No. 2253-1101. This regulation is enforced under the authority of the Civil Aviation Safety Authority and mandates compliance with the requirements set forth in the Rogerson Hiller Service Bulletin UH12-51-6 Revision dated 19 December 1985. The scope of these regulations extends to ensuring that the main rotor blade spar is inspected daily for bond separation and voids, with more intensive inspections at specified intervals to prevent potential structural failures. Compliance with these directives is crucial for maintaining the airworthiness of the aircraft, with particular attention to the daily inspection which can be performed by the pilot in command, requiring a certified entry in the Maintenance Release.

Key Provisions

The key operative sections of the Civil Aviation Regulations 1998, specifically Part 39 - 105, mandate the applicability and compliance requirements for the Airworthiness Directives concerning the Hiller UH-12 Series Helicopters. Section 39.105(1) outlines the applicability of the directive to all models of UH-12D, UH-12E, UH-12E4, OH-23F, OH-23G, and models converted by STC SH 178WE and STC SH 177 WE, provided they are equipped with the specified main rotor blades assembly, Parsons P/No. 2253-1101. The directive requires adherence to the actions detailed in Rogerson Hiller SB UH12-51-6 Revision dated 19 December 1985, which includes a daily visual inspection, a reduction in the dye penetrant inspection period, and the addition of a bond separation and void inspection by “coin tapping”. The obligations imposed by this Act require operators of the specified helicopters to conduct a daily visual inspection of the main rotor assembly to ensure there are no signs of bond separation or voids. This inspection must be documented in the Maintenance Release by the pilot in command or another authorised person. Additionally, the regulations mandate that the dye penetrant inspection period be reduced from 100 hours’ time in service to 25 hours’ time in service, and a bond separation and void inspection must be performed using the “coin tapping” method. These requirements are crucial to maintaining the structural integrity of the main rotor blades and ensuring the continued airworthiness of the helicopter. Failure to comply with the provisions of this directive may result in severe consequences. Section 39.105(3) stipulates that any non-compliance with the Airworthiness Directives can lead to civil or criminal penalties. While specific penalties are not detailed in the text, non-compliance with airworthiness directives can typically result in fines, suspension or revocation of the aircraft's certificate of airworthiness, and potential criminal charges against the operator or responsible parties. The severity of the penalties reflects the importance of adhering to these safety measures to prevent accidents and ensure the safety of all individuals involved in flight operations.