AD/AS 355/3 - Tail Rotor Blades, Bonding Separation of Stainless Steel Leading Edge Protectors - Inspection

Overview

The Civil Aviation Regulations 1998, as amended by the legislative instrument F2006B02483, address issues of airworthiness in relation to specific aircraft models, including the Eurocopter AS 355 (Twin Ecureuil) Series Helicopters. Enacted by the Australian Commonwealth Government, these regulations are administered by the Civil Aviation Safety Authority (CASA) and aim to ensure that aircraft meet the required safety standards. The specific focus of this legislative instrument is to mandate inspections and maintenance actions to mitigate the risk of bonding separation of the leading edge stainless steel protectors on the tail rotor blades of the AS 355 helicopters. This was introduced in response to reports of severe bonding separation incidents, necessitating timely inspections and adherence to manufacturer workcards to maintain operational safety. The policy objective behind these regulations is to enhance aviation safety by ensuring that critical components of helicopters are regularly inspected and maintained in accordance with the specified standards. This is achieved by setting clear timelines and intervals for inspections based on the operational hours of the tail rotor blades, thereby reducing the risk of in-flight failures due to structural issues. The regulations mandate inspections at intervals not exceeding 10 hours for blades with less than 100 hours of service and within 10 hours for blades exceeding 100 hours of service since their last overhaul, with specific reference to the Aerospatiale Workcard AS 355 No. 64.10.00.601 and Bureau Veritas AD 82-25-4(B).

Scope and Application

The Civil Aviation Regulations 1998, specifically PART 39 - 105, pertains to all model AS 355 helicopters equipped with particular tail rotor blades, namely 350A.12.0030.00 to.05. This legislation mandates compliance with Aerospatiale Workcard AS 355 No. 64.10.00.601, and references Bureau Veritas AD 82-25-4(B). The regulations require inspections and actions to address bonding separation of the stainless steel leading edge protectors on these helicopters, aimed at ensuring airworthiness. Compliance is required for helicopters that have been in service for less than 100 hours since new or overhaul, necessitating inspections before further flight and then at intervals not exceeding 10 hours until the accumulation of 100 hours of service. For helicopters that have been in service for more than 100 hours, inspections must be completed within 10 hours of 24 March 1982. These regulations apply nationwide under the jurisdiction of the Commonwealth of Australia and extend through subordinate instruments as required by the Civil Aviation Safety Authority.

Key Provisions

The main operative sections of the Civil Aviation Regulations 1998, PART 39 - 105, as they pertain to the Eurocopter AS 355 (Twin Ecureuil) Series Helicopters, require a specific inspection of the tail rotor blades. Section AD/AS 355/3 mandates that all model AS 355 helicopters fitted with tail rotor blades 350A.12.0030.00 to .05 must adhere to the action outlined in Aerospatiale Workcard AS 355 No. 64.10.00.601, referencing Bureau Veritas AD 82-25-4(B). The regulation specifies two different inspection intervals based on the service hours of the blades. For blades that have accumulated between 0 and 100 hours of service since new or overhaul, an inspection is required before further flight and then at intervals not exceeding 10 hours until the blades accumulate 100 hours of service. For blades that have more than 100 hours of service since new or overhaul, an inspection must occur within 10 hours of service following 24 March 1982. The obligations imposed by these regulations require operators of the Eurocopter AS 355 series helicopters to conduct thorough inspections of the tail rotor blades in accordance with the specified intervals. Operators must ensure that the inspections are performed by qualified personnel following the detailed procedures outlined in the Aerospatiale Workcard AS 355 No. 64.10.00.601, with reference to the Bureau Veritas AD 82-25-4(B). These inspections are critical to maintaining the airworthiness of the helicopters and preventing the separation of the leading edge stainless steel protectors, which has been reported by the manufacturer in several instances. Breaches of these regulatory requirements can result in significant legal consequences. Under the Civil Aviation Act 1988, non-compliance with airworthiness directives can lead to enforcement actions by the Civil Aviation Safety Authority (CASA). Offences involving the operation of an aircraft that does not meet airworthiness standards may result in penalties, including fines of up to $21,000 for individuals and $105,000 for corporations, as stipulated in the regulations. In severe cases, CASA may also suspend or revoke the aircraft's certificate of airworthiness, which can lead to the grounding of the aircraft and further legal repercussions for the operators involved. These penalties underscore the importance of adhering to the specified inspection intervals to ensure the safety and compliance of the aircraft.