AD/S-76/20 - Power Plant Mounting Supports - Inspection and Modification

Overview

The Civil Aviation Regulations 1998, specifically PART 39 - 105, establish a legislative framework designed to ensure the safety of civil aviation within Australia. The inclusion of the Sikorsky S-76 Series Helicopters AD/S-76/20 addresses a critical issue identified with the power plant mounting supports of these aircraft. This legislation was enacted by the Civil Aviation Safety Authority (CASA) to mitigate the risk of corrosion in the powerplant support assemblies due to entrapped water, which could compromise the structural integrity and safety of the helicopters. The regulation mandates that all affected models must undergo inspection and necessary modifications within 100 hours of time in service after 31 August 1981, unless these actions have already been completed. The policy objective is to ensure that all Sikorsky S-76 helicopters are maintained to a standard that prevents potential safety hazards, thereby protecting both the crew and passengers.

Scope and Application

The Civil Aviation Regulations 1998, as detailed in Part 39 - 105 under the Civil Aviation Safety Authority Schedule of Airworthiness Directives, specifically addresses the Sikorsky S-76 Series Helicopters. This legislation applies to all models of the S-76 helicopter fitted with powerplant support components that have specific part numbers as outlined in Sikorsky Customer Service Bulletin No. 76-71-6. The directive mandates that an inspection and modification be performed on the power plant mounting supports within 100 hours of time in service after 31 August 1981, or if these tasks have already been completed, they are deemed compliant. This requirement arises from reports of entrapped water causing corrosion in the powerplant support assembly tubes. The regulation's jurisdiction is nationwide, affecting all operators and entities within the Commonwealth of Australia, ensuring that safety standards are uniformly upheld across the aviation industry.

Key Provisions

The Civil Aviation Regulations 1998, under Part 39 - 105, specifically address the safety requirements for the Sikorsky S-76 series helicopters through Airworthiness Directives (AD). AD/S-76/20 pertains to the power plant mounting supports, stipulating that an inspection and, if necessary, a modification must be conducted on all S-76 models fitted with particular powerplant support components (section 39-105). The directive references Sikorsky Customer Service Bulletin No. 76-71-6 for the applicable parts numbers. This compliance must be achieved within 100 hours of time in service following 31 August 1981, or if the action has not already been completed. Operators and owners of the affected Sikorsky S-76 helicopters must adhere to the requirements set forth in AD/S-76/20. This involves conducting a thorough inspection of the specified power plant mounting supports to identify any corrosion caused by entrapped water. If corrosion is detected, the necessary modifications must be made in accordance with the manufacturer's guidelines as detailed in Sikorsky CSB No. 76-71-6. The inspection and any resultant modifications must be documented and completed within the stipulated timeframe to ensure compliance with the regulations. Failure to comply with AD/S-76/20 may result in serious safety risks, including potential engine failure or other structural issues that could compromise the aircraft's airworthiness. The Civil Aviation Safety Authority (CASA) has the authority to enforce compliance and may take appropriate action against non-compliant operators. Penalties for non-compliance could include fines and, in severe cases, the grounding of the aircraft until the required actions are taken. The exact penalties are not specified in the text but may be outlined in other sections of the Civil Aviation Regulations.