AD/S-76/36 - Fuselage - Engine Compartment Centre Firewall - Inspection of No. 1 Tail Drive Shaft for Adequate Clearance

Overview

The Civil Aviation Regulations 1998, specifically under PART 39 - 105, were enacted to ensure the safety and efficiency of civil aviation in Australia. The legislative instrument F2006B06717 addresses a specific safety concern for Sikorsky S-76 Series Helicopters, particularly the S-76A model, requiring inspections of the No. 1 tail drive shaft to ensure adequate clearance and prevent potential engine compartment fires. This directive was introduced in response to reports of tail rotor drive shaft severance due to interference with a particular doubler part. The Australian Parliament enacted these regulations to align with international safety standards and to mitigate risks associated with civil aviation, thereby protecting both crew and passengers. The objective of this safety directive is to mandate compliance with Sikorsky's Alert S.B. 76-53-24 and CBT-TP-84-098, ensuring that the No. 1 tail drive shaft is inspected before further flight after 12 February 1985. This proactive approach aims to prevent catastrophic failures by addressing potential design and maintenance issues that could compromise the structural integrity and operational safety of the aircraft. The Civil Aviation Safety Authority, through this legislative instrument, reinforces its commitment to maintaining high safety standards in the aviation sector.

Scope and Application

The Civil Aviation Regulations 1998, specifically Part 39 - 105, addresses the application of the Airworthiness Directives (AD) concerning Sikorsky S-76 Series Helicopters, focusing on a critical safety issue. This regulation applies to all model S-76A helicopters, requiring mandatory compliance with Sikorsky Alert S.B. 76-53-24 and Sikorsky CBT-TP-84-098. The requirement mandates that an inspection of the No. 1 tail drive shaft for adequate clearance must be performed unless it has already been accomplished before further flight following 12 February 1985. This directive is a direct response to a reported incident where the No. 1 section tail rotor drive shaft became severed due to interference with doubler P/N 76070-20057-101, highlighting the importance of adhering to these safety measures. The regulation's jurisdiction is under the Commonwealth of Australia, ensuring a national standard for the safe operation of these helicopters.

Key Provisions

The Civil Aviation Regulations 1998, particularly Part 39 - 105, outlines the Civil Aviation Safety Authority's (CASA) Schedule of Airworthiness Directives. One such directive, AD/S-76/36, specifically pertains to Sikorsky S-76 Series Helicopters (section 39-105). This directive mandates an inspection of the No. 1 Tail Drive Shaft for adequate clearance in the engine compartment centre firewall of all model S-76A Helicopters. The directive references Sikorsky Alert S.B. 76-53-24 and Sikorsky CBT-TP-84-098. It requires compliance before further flight, unless the inspection has already been conducted since 12 February 1985. The primary obligations under AD/S-76/36 are to ensure that the No. 1 Tail Drive Shaft is inspected for adequate clearance within the engine compartment centre firewall. This inspection must be carried out on all model S-76A Helicopters, as specified in the directive. The requirement applies unless the inspection has already been performed since the date of the directive, 12 February 1985. The directive references specific Sikorsky alerts and compliance technical publications, which detail the inspection procedure and criteria for compliance. Failure to comply with AD/S-76/36 could result in significant consequences. The directive stems from a reported incident where the No. 1 section tail rotor drive shaft became severed due to interference with doubler P/N 76070-20057-101. The consequences of non-compliance could include compromised flight safety, leading to potential accidents or incidents. While the Civil Aviation Regulations do not explicitly state penalties for non-compliance with airworthiness directives, failure to adhere to such directives can lead to enforcement actions by CASA, which may include fines, suspension or revocation of certificates, and other regulatory measures. The severity of these consequences underscores the importance of adhering to the directive to ensure the safety of all flights.