COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY
SCHEDULE OF AIRWORTHINESS DIRECTIVES
Robinson R44 Series Helicopters
AD/R44/6 Main Rotor Gearbox 12/96 DM
Applicability: This Directive is applicable to all R44 helicopters with S/N 0001 through 0232 fitted with main rotor gearbox P/N C006-1 Revision A through P. Helicopters S/N 0019, 0067, 0118, 0135 and 0215 are already in compliance with this Directive.
Requirement: Unless previously carried out, action in accordance with Robinson R44 SB No 15 dated 2 August 1996. Report any fretting or loose bolts by MDR action.
Note: FAA Priority Letter AD 96-18-22 refers.
Compliance: Within 100 hours time in service from 11 September 1996 or prior to 1 October 1996, whichever occurs first.
Background: An overseas inflight failure of a main rotor gearbox has been reported. Inspection of the gearbox revealed that the 18 bolts securing the ring gear, P/N C146-3, to the gear carrier, P/N C268-2, had lost clamping torque which then resulted in fretting and failure of the gear carrier.
Overview
The Civil Aviation Regulations 1998, specifically PART 39 - 105, addresses the issue of maintaining the airworthiness of aircraft through the issuance of airworthiness directives. This legislative instrument was enacted to ensure that all civil aircraft operating in Australia meet the necessary safety standards to protect passengers and crew. The problem it was introduced to address includes the need to respond promptly and effectively to any identified safety issues that may affect aircraft operation, including the requirement for mandatory inspections and repairs as specified in airworthiness directives. The policy objective is to enhance safety and reliability in civil aviation by ensuring that aircraft are maintained in a safe and airworthy condition.
The enacting body responsible for these regulations is the Civil Aviation Safety Authority (CASA), which operates under the authority of the Australian Government. The Authority issues airworthiness directives, such as AD/R44/6, to address specific safety concerns related to particular aircraft models. These directives mandate corrective actions and establish compliance timelines to mitigate risks associated with identified safety issues. In the case of the Robinson R44 Series Helicopters, AD/R44/6 pertains to the main rotor gearbox, requiring inspections and actions to prevent failures that could lead to significant safety hazards.
Scope and Application
The Civil Aviation Safety Authority (CASA) Schedule of Airworthiness Directives, specifically AD/R44/6, pertains to Robinson R44 Series helicopters with serial numbers ranging from 0001 to 0232 that are fitted with main rotor gearbox parts numbered from C006-1 Revision A through P. The directive is designed to ensure the airworthiness of these helicopters by addressing a specific mechanical issue identified in the main rotor gearbox. Notably, certain helicopters with serial numbers 0019, 0067, 0118, 0135, and 0215 are already compliant with the requirements of this directive. The regulation mandates that unless the specified action has already been taken, operators must follow Robinson R44 Service Bulletin No 15 dated 2 August 1996 and report any instances of fretting or loose bolts through mandatory defect reporting (MDR) actions. This requirement is in response to a reported overseas in-flight failure of a main rotor gearbox, which was traced to the loss of clamping torque of the 18 bolts securing the ring gear to the gear carrier, leading to fretting and failure of the gear carrier. Operators are required to comply with the directive within 100 hours of the helicopter’s time in service from 11 September 1996, or prior to 1 October 1996, whichever comes first. The directive is applicable across the Commonwealth of Australia and extends its reach through the Civil Aviation Regulations 1998, which are enforced by CASA.
Key Provisions
The key provisions of the Civil Aviation Regulations 1998, specifically in Part 39 - 105, address the Airworthiness Directives for Robinson R44 Series Helicopters, particularly in relation to the main rotor gearbox (AD/R44/6). This directive applies to R44 helicopters with serial numbers 0001 through 0232, provided they are equipped with main rotor gearbox part numbers C006-1 Revision A through P. The directive excludes helicopters with serial numbers 0019, 0067, 0118, 0135, and 0215, which are already compliant with this directive. The directive requires that, unless previously executed, action be taken in accordance with Robinson R44 Service Bulletin No. 15 dated 2 August 1996. This action includes reporting any instances of fretting or loose bolts via Mandatory Disposition Reporting (MDR).
The obligations imposed by this directive are quite specific. Operators of the affected helicopters must ensure that the inspection and necessary actions are completed within 100 hours of time in service from 11 September 1996, or before 1 October 1996, whichever comes first. The directive mandates that any fretting or loose bolts in the 18 bolts securing the ring gear to the gear carrier must be reported and addressed to prevent potential failure of the gear carrier. This is critical as an overseas inflight failure of a main rotor gearbox has already been reported due to a similar issue.
Failure to comply with this directive can result in serious consequences. The regulations stipulate that non-compliance with Airworthiness Directives is an offence under the Civil Aviation Act 1988. In the case of this directive, the potential for an inflight failure of the main rotor gearbox poses significant risks to safety, which underscores the importance of adherence. The penalties for breaching these regulations can include substantial fines and, in severe cases, imprisonment. The exact penalties are not specified in the directive itself but are generally aligned with the Civil Aviation Act 1988, which provides for fines and imprisonment for serious non-compliance with airworthiness directives.