AD/DHE/1 - Accessory Drive Shaft - Modification to Provide Weak Neck

Overview

The Civil Aviation Regulations 1998, as amended by F2006B09259, specifically address the safety and airworthiness of aircraft through the Civil Aviation Safety Authority (CASA) Schedule of Airworthiness Directives. This particular legislative instrument targets De Havilland Piston Engines, specifically the Gipsy Six II and Gipsy Queen II, by mandating modifications to the accessory drive shaft to mitigate the risk of a weak neck, which could lead to engine failure. This was introduced to ensure the safety and reliability of these engines in Australian civil aviation, aligning with the overarching policy objective of maintaining the highest safety standards. The modifications outlined in the legislative instrument are to be completed before the engine is installed in an aircraft, ensuring that all engines meet the required safety criteria.

Scope and Application

The Civil Aviation Regulations 1998, specifically Part 39 - 106, which pertains to the Civil Aviation Safety Authority's Schedule of Airworthiness Directives, applies to the modification of accessory drive shafts on De Havilland Gipsy Six II and Gipsy Queen II piston engines. This regulation mandates compliance with modifications as outlined in DH Mod. G1018, DH Mod. G1079, or ANO 106.1.7.0.1.1.1. before these engines are installed in any aircraft, ensuring the engines meet necessary safety standards. The application of this regulation extends across the Commonwealth of Australia, affecting all entities and persons involved in the manufacture, maintenance, or operation of aircraft equipped with the specified De Havilland piston engines. The regulation does not specify exclusions or exemptions, meaning that all applicable engines must adhere to the modifications regardless of the specific circumstances or location within Australia. Subordinate instruments may further detail or extend the application of these directives, but the primary requirement remains the modification of the accessory drive shafts to address the identified safety issue.

Key Provisions

The Civil Aviation Regulations 1998, specifically Part 39, Section 106, mandate the airworthiness directives issued by the Civil Aviation Safety Authority (CASA). This legislative instrument pertains to modifications of De Havilland piston engines, particularly for Gipsy Six II and Gipsy Queen II models, as outlined in the Accessory Drive Shaft Modification (AD/DHE/1) concerning the weak neck issue. The modifications are to be implemented in accordance with either DH Mod. G1018, DH Mod. G1079, or ANO 106.1.7.0.1.1.1. Compliance with these directives is mandatory before the engines are installed in any aircraft. The obligations imposed by this Act require that all Gipsy Six II and Gipsy Queen II engines undergo a specified modification to the accessory drive shaft to address the weak neck issue. This is to ensure that the engines meet the required airworthiness standards set forth by CASA. The modifications must be executed meticulously to avoid any compromise on the safety of the aircraft. The compliance must be verified before the engines are installed, which means that any engine modifications must be completed, inspected, and certified as compliant with the directive before being integrated into an aircraft. Failure to comply with these airworthiness directives can result in serious consequences. The Act outlines that non-compliance with the specified modifications and compliance checks may lead to civil or criminal penalties. While the specific penalties are not detailed in the provided text, it is evident that the oversight of CASA is strict, and any breach of these directives could result in significant legal and financial repercussions for the parties involved. The overarching goal is to maintain the highest safety standards in civil aviation, ensuring that all aircraft and their components meet the stringent requirements set by the regulations.