AD/S-76/9 - Cyclic Torque Tube - Inspection of Centre Support Bearing Housing

Overview

The Civil Aviation Regulations 1998, specifically within Part 39, addresses issues concerning the airworthiness of aircraft through the issuance of various directives. One such directive, AD/S-76/9, focuses on Sikorsky S-76 Series Helicopters and mandates an inspection of the cyclic torque tube's centre support bearing housing. Enacted by the Commonwealth of Australia, this regulation was introduced to address a critical safety concern identified in the Sikorsky S-76 series helicopters. The problem arose from the incorrect manufacturing of certain bearing support housings, which could lead to axial displacement of the bearing along the torque tube, potentially compromising the helicopter's structural integrity and safety. The directive requires compliance within 10 hours of the aircraft being in service after 14 February 1980, as documented in Sikorsky CSB 76-67-7, underscoring the Civil Aviation Safety Authority's commitment to maintaining stringent safety standards in aviation.

Scope and Application

The Civil Aviation Regulations 1998, specifically Part 39 - 105, under the authority of the Civil Aviation Safety Authority, include Airworthiness Directives that apply to certain aircraft models to ensure safety standards are met. For instance, AD/S-76/9 pertains to Sikorsky S-76 series helicopters and mandates the inspection of the centre support bearing housing of the cyclic torque tube. This directive applies to all models within the S-76 series and is crucial for ensuring the structural integrity of the aircraft. Compliance with this directive is required within 10 hours of time in service after 14 February 1980, reflecting a critical safety measure to address manufacturing defects where some bearing support housings were incorrectly manufactured, potentially allowing axial displacement of the bearing along the torque tube. This requirement underscores the importance of regular inspections to mitigate risks associated with these defects, ensuring the ongoing airworthiness of the aircraft.

Key Provisions

The Civil Aviation Regulations 1998, specifically Part 39 - 105 (1) under the Civil Aviation Safety Authority Schedule of Airworthiness Directives, address the inspection of the centre support bearing housing for the Sikorsky S-76 Series Helicopters. This directive, known as AD/S-76/9, requires that the inspection be conducted within 10 hours of time in service after 14 February 1980, as documented in Sikorsky CSB 76-67-7. The purpose of this directive is to address an issue where some bearing support housings were manufactured incorrectly, with the bearing retaining shoulder positioned on the wrong side. This manufacturing error could allow for axial displacement of the bearing along the torque tube, which is a critical safety concern. The obligations imposed by this directive are clear and specific. Helicopter operators and owners must ensure that the inspection of the centre support bearing housing is conducted in accordance with the specified timeline. This involves verifying that the bearing retaining shoulder is correctly positioned to prevent any potential axial displacement that could compromise the safety of the aircraft. The directive underscores the importance of adhering to the manufacturer's guidelines and the necessity of timely inspections to mitigate safety risks. Failure to comply with the requirements set out in AD/S-76/9 could lead to severe consequences. The Civil Aviation Regulations 1998 stipulate that non-compliance with airworthiness directives can result in significant penalties. Operators and owners found in breach of this directive may face both civil and criminal consequences. Civil penalties can include substantial fines, while criminal penalties can involve imprisonment, reflecting the seriousness of ensuring aviation safety standards are met. The exact penalties are determined by the courts but can be severe given the potential impact on flight safety.