Overview

The Airworthiness Directive issued by the Civil Aviation Safety Authority (CASA) in 2002 is a legislative instrument designed to address safety concerns associated with the Eurocopter AS 355 (Twin Ecureuil) Series Helicopters. This directive, specifically AD/AS 355/57 Amendment 1, was introduced in response to reports of cracks in tail rotor pitch change plate bearings, which could potentially lead to malfunctions and loss of control of the aircraft. The directive mandates the replacement of certain tail rotor pitch change bearings for different versions of the AS 355 helicopters and outlines specific intervals for bearing replacement and compliance based on flight hours since new. The policy objective of this directive is to ensure the continued airworthiness and safety of the affected helicopters by rectifying the identified unsafe condition. This legislative measure was enacted to comply with subregulation 39.1 (1) of the Civil Aviation Regulations 1998, and the directive became effective on 31 October 2002.

Scope and Application

The Airworthiness Directive issued by the Civil Aviation Safety Authority (CASA) applies specifically to all versions of the Eurocopter AS 355 (Twin Ecureuil) Series Helicopters, namely the E, F, F1, F2, and N models, that are equipped with tail rotor hub pitch change plate SNR bearings, specifically P/No 6010F234M16 (704A33-651-190). This directive mandates the replacement of these bearings to address a safety issue identified by the DGAC, which reported instances of cracks leading to potential malfunction and loss of control. The requirement to replace these bearings varies by model, with AS 355N versions necessitating replacement at 300 flight hours bearing time since new, and subsequent replacements every 300 flight hours. For the AS 355 E, F, F1, and F2 versions, the initial replacement is required at 1200 flight hours bearing time since new, with subsequent replacements at every 1200 flight hours. The directive also provides guidelines for transferring bearings between different AS 355 versions, as detailed in the Master Servicing Manual. This AD is applicable throughout the Commonwealth of Australia, and its provisions are enforced under the Civil Aviation Regulations 1998, with amendments becoming effective as specified in the directive.

Key Provisions

This Airworthiness Directive (AD) AD/AS 355/57 Amendment 1 (AD/AS 355/57 Amdt 1) revokes the previous AD AD/AS 355/57 and introduces new requirements for the replacement of tail rotor pitch change bearings in Eurocopter AS 355 series helicopters. Specifically, the AD applies to all AS 355 helicopters (versions E, F, F1, F2, and N) fitted with the specified tail rotor hub pitch change plate SNR bearing, P/No 6010F234M16 (704A33-651-190) (applicability section). The requirement section mandates the replacement of these bearings to address potential cracks that may lead to malfunction and loss of control. The compliance section outlines different intervals for replacing these bearings based on the model of the helicopter: for the AS 355N version, replacement is required at 300 flight hours bearing time since new, and thereafter every 300 flight hours; for the AS 355 E, F, F1, and F2 versions, replacement is required at 1200 flight hours bearing time since new, and thereafter every 1200 flight hours. If bearings are to be transferred between models, the transfer rules defined in the Master Servicing Manual, Chapter 05.99, Page P8, must be applied. This Amendment becomes effective on 31 October 2002. The AD imposes obligations on the parties or entities it governs, which include operators, maintenance providers, and potentially helicopter owners. Operators must ensure that the specified tail rotor pitch change bearings are replaced in accordance with the outlined intervals. Maintenance providers are responsible for conducting the necessary inspections and replacements as per the AD. Owners of these helicopters must ensure that their operators and maintenance providers are aware of and comply with the requirements of this AD. Failure to adhere to these requirements could result in unsafe conditions that may lead to serious accidents or incidents. Breach of the requirements outlined in this AD may lead to civil or criminal consequences. While the AD itself does not explicitly state the penalties for non-compliance, failure to comply with airworthiness directives can result in civil penalties under the Civil Aviation Act 1988 (Cth) and potentially criminal penalties under the Criminal Code Act 1995 (Cth). Civil penalties for non-compliance with airworthiness directives may include fines of up to $1,650,000 for corporations and $330,000 for individuals, as well as potential disqualification from holding a pilot licence or aircraft maintenance licence. Criminal penalties may include imprisonment for up to five years, reflecting the serious nature of non-compliance with safety regulations in the aviation industry.