AD/S-76/54 - Main Gearbox Tail Takeoff Flange Locknut

Administered by Department of Infrastructure, Transport, Regional Development, Communications, Sport and the Arts

Legislation au F2006B06730 Not in force Legislative Instrument

Legislation content

COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY

SCHEDULE OF AIRWORTHINESS DIRECTIVES

 


Sikorsky S-76 Series Helicopters

 

AD/S-76/54 Main Gearbox Tail Takeoff Flange Locknut 7/89

Applicability: All S-76A helicopters fitted with P/N 76351-09500 series main gearboxes.

 

All S-76B helicopters fitted with P/N 76351-09600 series main gearbox up to and including S/N A231-00038.

 

Requirement: Action in accordance with Sikorsky Alert Service Bulletin 76-66-23. Compliance: By 31 August 1989.

Background: Due to torque loss of the tail takeoff flange locknut, specific tests to detect this torque loss are required.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Overview

The Civil Aviation Regulations 1998, as amended by the Legislative instrument F2006B06730, address the issue of ensuring the airworthiness of the Sikorsky S-76 Series Helicopters. This legislative instrument was enacted to mitigate risks associated with the torque loss of the tail takeoff flange locknut, which could potentially lead to significant safety concerns. The Civil Aviation Safety Authority (CASA) introduced this regulation to ensure that all applicable S-76A and S-76B helicopters are maintained in a safe and airworthy condition by requiring compliance with specific maintenance actions as outlined in Sikorsky Alert Service Bulletin 76-66-23. The policy objective is to enhance the safety of civil aviation by enforcing rigorous maintenance standards and ensuring adherence to the stipulated compliance deadline of 31 August 1989.

Scope and Application

The Civil Aviation Regulations 1998, specifically Part 39 - 105 concerning the Civil Aviation Safety Authority Schedule of Airworthiness Directives, applies to all S-76A helicopters equipped with P/N 76351-09500 series main gearboxes, and all S-76B helicopters fitted with P/N 76351-09600 series main gearboxes up to and including S/N A231-00038. This legislation mandates compliance with Sikorsky Alert Service Bulletin 76-66-23, which includes specific tests to detect the torque loss of the tail takeoff flange locknut. The requirement is that all affected aircraft must adhere to the specified compliance measures by 31 August 1989. The regulations pertain to the maintenance and safety standards of these aircraft, ensuring that the specified gearboxes are tested and maintained according to the set directives. This legislation underscores the importance of adhering to manufacturer guidelines to ensure the airworthiness of the aircraft and the safety of all individuals on board.

Key Provisions

The Civil Aviation Regulations 1998 (Cth) under Part 39 - 105, specifically the Airworthiness Directives for Sikorsky S-76 Series Helicopters (AD/S-76/54), mandates that all S-76A helicopters equipped with P/N 76351-09500 series main gearboxes, and all S-76B helicopters fitted with P/N 76351-09600 series main gearboxes up to and including serial number A231-00038, must comply with the action outlined in Sikorsky Alert Service Bulletin 76-66-23. This directive is necessitated by the issue of torque loss in the tail takeoff flange locknut, which requires specific tests to detect such losses. Compliance with these directives is mandatory and must be achieved by 31 August 1989. The Civil Aviation Regulations 1998 impose a series of obligations on the operators of Sikorsky S-76 Series helicopters. Firstly, operators must ensure that the applicable helicopters are fitted with the specified main gearboxes and serial numbers as outlined in the directive. Secondly, they must follow the precise actions detailed in the Sikorsky Alert Service Bulletin 76-66-23 to address the torque loss issue in the tail takeoff flange locknut. These actions may include conducting specific tests, making necessary repairs, or replacing parts to ensure that the helicopters meet the required airworthiness standards. Compliance with these obligations is critical to maintaining the safety and airworthiness of the helicopters. Failure to comply with the Civil Aviation Regulations 1998 as they pertain to the Sikorsky S-76 Series helicopters can result in serious consequences. The regulations do not explicitly state specific offences, penalties, or consequences for non-compliance in this context. However, under broader aviation safety legislation, non-compliance with airworthiness directives can lead to significant civil and criminal penalties. These may include substantial fines, the potential grounding of the non-compliant aircraft, and in severe cases, criminal charges against the operators or maintenance personnel responsible for the non-compliance. The specific penalties would depend on the nature and extent of the breach, as well as any resulting safety risks or incidents.

Legal classification tags

Area of Law
Civil Aviation Law
Instrument
Regulation
Concepts
Definitions & Interpretation
Regulatory Standards
Compliance Obligations
Catchwords
Airworthiness Directives

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Sourced from the Federal Register of Legislation at 26 August 2026. For the latest information on Australian Government law please go to https://www.legislation.gov.au.