AD/AS 355/37 - Tail Rotor Pitch Control Lever Expansion Pin

Overview

The Civil Aviation Regulations 1998, specifically PART 39 - 105, addresses the safety requirements for airworthiness directives in the context of civil aviation within Australia. Enacted by the Australian Government, this regulation aims to ensure that all aircraft meet specific safety standards, thus enhancing the overall safety of air travel. The regulation fills a critical gap by establishing clear and enforceable directives for aircraft manufacturers and operators to follow, thereby minimising the risk of in-flight failures due to mechanical issues. The policy objective is to safeguard passengers, crew, and the public by mandating stringent airworthiness standards and compliance with internationally recognised technical requirements. The Civil Aviation Regulations 1998 were introduced to standardise and enforce airworthiness directives, ensuring that all aircraft, including the Eurocopter AS 355 (Twin Ecureuil) series helicopters, adhere to safety protocols. This legislative instrument was enacted by the Commonwealth of Australia and is managed under the Civil Aviation Safety Authority. It specifically targets the issue of mechanical failure in the tail rotor gearbox control lever hinge yoke of the mentioned helicopter models, requiring compliance with the Technical Requirements of DGAC TAD T91-138-043 (B) to prevent such failures from occurring.

Scope and Application

The Civil Aviation Regulations 1998, specifically Part 39 - 105, applies to all Eurocopter AS 355 helicopters versions E, F, F1, F2, and N. These regulations mandate compliance with the Airworthiness Directives regarding the tail rotor pitch control lever expansion pin, as outlined in AD/AS 355/37. The directive requires adherence to the technical requirements specified in DGAC TAD T91-138-043 (B) and references Aerospatiale TSB 01-34. This legislation ensures that the specified models of AS 355 helicopters meet stringent safety standards to prevent failures such as the one caused by incorrect assembly of the bushes on the expansion pin. Compliance must be achieved as per the requirement document, with the revised effective date set at 10 July 1991. The scope of this directive extends to all relevant helicopter operators and maintenance personnel within the Commonwealth of Australia, ensuring the continued airworthiness and safety of the specified aircraft.

Key Provisions

The Civil Aviation Regulations 1998, specifically Part 39 - 105, mandate that all operators of Eurocopter AS 355 (Twin Ecureuil) Series Helicopters adhere to Airworthiness Directives (AD) as outlined in AD/AS 355/37. The primary focus of this directive is to address a critical issue with the tail rotor pitch control lever expansion pin, which was found to be incorrectly assembled, leading to the failure of one lug of the tail rotor gearbox control lever hinge yoke (section 1). The directive requires operators to take action in accordance with the technical requirements specified in DGAC TAD T91-138-043 (B), and references Aerospatiale TSB 01-34 for further guidance. Compliance with these directives must be achieved by following the requirement document, with a revised effective date of 10 July 1991. Operators of the affected AS 355 helicopter versions, namely E, F, F1, F2, and N, are obligated to ensure that the tail rotor pitch control lever expansion pin is correctly assembled to prevent similar failures. This involves following the detailed procedures outlined in the referenced technical documents to rectify any issues with the expansion pin and the associated control lever hinge yoke. Ensuring compliance with these directives is critical for maintaining the airworthiness of the aircraft and ensuring the safety of all personnel on board. Failure to comply with the provisions of AD/AS 355/37 may result in severe consequences. The Civil Aviation Safety Authority (CASA) may take enforcement action against operators who do not adhere to these directives. Potential penalties for non-compliance can include fines, enforcement notices, and even the grounding of non-compliant aircraft. In extreme cases, the authority to operate the aircraft may be revoked, leading to significant operational disruptions and financial losses for the operator. It is imperative that operators take the necessary steps to ensure their aircraft meet the specified airworthiness standards to avoid these penalties and ensure continued compliance with aviation safety regulations.