AD/ECUREUIL/37 Amdt 1 - Tail Rotor Control Spider

Overview

The Civil Aviation Regulations 1998, specifically Part 39 - 105, addresses the safety and compliance of civil aviation operations within Australia. Enacted by the Parliament of the Commonwealth of Australia, this regulation was introduced to ensure that all civil aviation activities adhere to stringent safety standards, thereby protecting the public and maintaining the integrity of the nation's air traffic management system. One such regulation, AD/ECUREUIL/37 Amendment 1, pertains to the maintenance and inspection of the tail rotor control spider on Eurocopter AS 350 (Ecureuil) Series Helicopters, addressing the specific problem of nut loosening on the pitch control spider. The policy objective behind this directive is to enhance the safety and reliability of helicopter operations by enforcing meticulous maintenance protocols and ensuring that any identified issues are promptly rectified.

Scope and Application

The Civil Aviation Regulations 1998, specifically Part 39 - 105, mandates the application of Airworthiness Directives to ensure the safety of aircraft operations within Australia. This legislative instrument targets all Eurocopter AS 350 (Ecureuil) Series helicopters equipped with specific tail rotor control spider part numbers, necessitating compliance with the outlined requirements to maintain airworthiness. The geographic scope of this regulation is national, applying to all aircraft registered in Australia. The directive specifies the procedures for inspection and maintenance of the tail rotor control spider, including removal, visual inspection, and replacement if necessary, and mandates specific steps when refitting the control spider assembly. Compliance is required within a specified timeframe after the directive's issuance, with additional checks required whenever the tail rotor control spider assembly is installed. This directive extends to address reported instances of nut loosening on the pitch control spider, with amendments to include additional part numbers for affected spiders. The regulation does not explicitly state exclusions but implies that it applies to all relevant aircraft within the specified scope.

Key Provisions

The Civil Aviation Regulations 1998, specifically Part 39 - 105, include a schedule of airworthiness directives that are essential for maintaining the safety of aircraft operations. One such directive pertains to the Eurocopter AS 350 (Ecureuil) Series Helicopters, specifically AD/ECUREUIL/37 Amendment 1, which addresses issues with the tail rotor control spider. Section 1 of the directive outlines the applicability to all model AS 35 helicopters fitted with particular tail rotor control spiders (1(a)). It requires operators to remove the hub assembly, spider assembly, and non-rotating spider to visually inspect the condition of the nut lockwasher, bushes, and bearing baffles and journals (1(b)). Depending on the findings, the directive either permits reassembly of the control spider if there is no evidence of bearing race rotation, metal fretting, or pick-up or mandates the replacement of the spider assembly if such evidence is present (1(c) and (d)). In addition to the removal and inspection requirements, section 2 details the procedure for fitting the control spider assembly (2). Operators must scrap and replace the existing lock washer with a new one, tighten the nut to a specified torque of 60 Nm (530 inch lbs), release the nut by a quarter turn, and then retorque it to between 40 and 60 Nm (355-530 inch lbs) to ensure safetying. The directive also specifies that the nut should be safetyed with 0.8mm lockwire (2(c) and (d)). Furthermore, if the nut cannot be safetyed within the specified torque range, it must be scrapped and replaced (Note 1). The directive refers to two Aerospatiale telex communications for further information (Note 2). Compliance with this directive is crucial. For paragraph 1, the inspection and necessary actions must be carried out within 100 hours of time in service after 31 July 1987, unless already accomplished (Compliance: For Para 1). For paragraph 2, the fitting procedure must be followed any time the tail rotor control spider assembly is installed (Compliance: For Para 2). Failure to adhere to these requirements can lead to safety issues, as evidenced by several reported cases of nut loosening on the pitch control spider. This directive aims to mitigate such risks by ensuring proper maintenance and inspection procedures are followed. Non-compliance with the airworthiness directive could result in significant consequences. The Civil Aviation Safety Authority (CASA) has the authority to impose penalties for breaches of the Civil Aviation Regulations, including fines and potential grounding of the aircraft until the issues are rectified. While specific penalties are not detailed within the directive itself, they are governed by the broader regulatory framework under which CASA operates. Ensuring adherence to these directives is vital to maintaining the safety standards required by Australian civil aviation regulations.