AD/AS 355/23 - Hydraulic System

Overview

The Civil Aviation Regulations 1998, specifically Part 39 - 105 Civil Aviation Safety Authority Schedule of Airworthiness Directives, addresses the safety of Eurocopter AS 355 (Twin Ecureuil) Series Helicopters through the directive AD/AS 355/23, issued on 12 August 1986. This legislative instrument was enacted by the Civil Aviation Safety Authority to ensure the continued airworthiness of these helicopters by mandating specific actions concerning the hydraulic system. The directive aims to mitigate the risk of overpressure in the hydraulic systems if the flange of the regulator valve stem, fitted to the filter unit, should come off. This requirement is in accordance with Aerospatiale AS 355 Service Bulletin No. 29-01 and references French AD 86-150-30(B). Compliance must be achieved within 300 hours of time in service after 30 November 1986 or before 31 January 1987, whichever occurs first, and also applies to spares before installation in an aircraft after 30 November 1986. The Civil Aviation Regulations 1998 were enacted by the Parliament of the Commonwealth of Australia to regulate civil aviation and ensure safety standards are met. This particular directive under the Regulations was issued to address a specific safety concern related to the hydraulic system of the Eurocopter AS 355 helicopters. By mandating compliance with the Aerospatiale Service Bulletin and referencing relevant French airworthiness directives, the policy objective is to maintain the safety and reliability of these aircraft through timely and standardised maintenance actions.

Scope and Application

The Civil Aviation Regulations 1998, specifically Part 39 - 105, mandates airworthiness directives for various aircraft types, including the Eurocopter AS 355 (Twin Ecureuil) Series Helicopters. These directives apply to all model AS 355 E, F, F1, and F2 helicopters. The legislation requires compliance with Aerospatiale AS 355 Service Bulletin No. 29-01 concerning the hydraulic system. This directive references French AD 86-150-30(B) and mandates that specific actions be taken within a specified timeframe, either 300 hours of time in service after 30 November 1986 or before 31 January 1987, whichever occurs first. For spares intended for installation in an aircraft, the compliance must occur before installation after 30 November 1986. This directive ensures the installation of a spring spacer to prevent overpressure in the hydraulic system if the flange of the regulator valve stem, fitted to the filter unit, should come off. This regulation is implemented under the Commonwealth of Australia and is overseen by the Civil Aviation Safety Authority.

Key Provisions

The Civil Aviation Regulations 1998, specifically in Part 39 - 105, include a directive concerning the airworthiness of Eurocopter AS 355 (Twin Ecureuil) Series Helicopters. Section AD/AS 355/23 pertains to the hydraulic system of these helicopters, as outlined in Aerospatiale AS 355 Service Bulletin No. 29-01. This directive applies to all model AS 355 E, F, F1, and F2 helicopters. The requirement is that actions must be taken to ensure compliance with the specified service bulletin. This directive references French AD 86-150-30(B) for additional context. These regulations impose clear obligations on the parties involved. Operators of the specified Eurocopter AS 355 models must adhere to the directive concerning the hydraulic system within the specified timeframe. This involves ensuring that a spring spacer is fitted to prevent overpressure in the hydraulic system if the flange of the regulator valve stem, which is part of the filter unit, should come off. The compliance deadline is set at 300 hours of time in service after 30 November 1986, or before 31 January 1987, whichever comes first. For spares, the compliance requirement applies before they are installed in an aircraft after 30 November 1986. Failure to comply with these airworthiness directives can result in serious consequences. The Civil Aviation Regulations 1998 do not explicitly state penalties for non-compliance in this context; however, non-compliance with airworthiness directives generally can lead to significant civil or criminal penalties under other sections of the Civil Aviation Act 1988. The potential consequences may include fines, suspension or revocation of air operator certificates, and other regulatory actions. The specific penalties can vary depending on the severity of the breach and the applicable sections of the legislation.