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-76/26
Amdt 1
Vertical Stabiliser Pylon Leading Edge Skin 11/85
Applicability: All models.
Requirement: 1. Sikorsky Alert Service Bulletin No. 76-55-9; or
2. Sikorsky Alert Service Bulletin No. 76-55-11 (Terminating Action); or
3. Sikorsky Customer Service Notice No 76-141B (Terminating Action). Compliance: For para. E(1) of ASB 76-55-9: Within the next 25 hours time in service after 25
March 1983 and thereafter at intervals not exceeding 25 hours time in service.
For para. E(2) of ASB 76-55-9: Within the next 100 hours time in service after 25 March 1983 and thereafter at intervals not exceeding 100 hours time in service.
Background: Cracks have been found in service in the pylon upper leading edge skin near the tail rotor gear box. This Directive has been amended to provide terminating action for modified helicopters. However, note that CSN 76-141 no longer constitutes terminating action for the requirements of AD/S-76/29. The reason is that forward spar cracks have been found in modified helicopters, although at this stage there have been no reports of L.E. skin cracks. It is expected that an improved modification will be developed by the manufacturer.
Overview
The Civil Aviation Regulations 1998, amended by the Civil Aviation Amendment (Safety) Regulations 2019, address critical safety issues within the aviation sector by ensuring that aircraft maintenance and operational standards are upheld. This legislative instrument specifically targets the Sikorsky S-76 Series Helicopters, issuing Airworthiness Directives to manage known structural issues. The problem addressed by this regulation is the occurrence of cracks in the vertical stabiliser pylon leading edge skin near the tail rotor gearbox, which poses significant safety risks during flight. The enactment by the Australian Government under the authority of the Civil Aviation Act 1988 aims to enhance the safety of civil aviation by mandating specific inspection and maintenance actions to prevent such structural failures. The policy objective is to ensure that all Sikorsky S-76 helicopters remain airworthy by adhering to the stipulated inspection intervals and modification requirements.
Scope and Application
The Civil Aviation Regulations 1998, specifically Part 39 - 105, pertains to the airworthiness directives issued by the Civil Aviation Safety Authority (CASA). This legislative instrument, known as AD/S-76/26 Amendment 1, applies to all models of the Sikorsky S-76 Series Helicopters, mandating compliance with certain service bulletins and customer notices issued by Sikorsky. The geographic reach of these regulations is national, encompassing all helicopters operating within Australia. The primary requirement outlined in the legislation mandates that helicopter operators ensure adherence to Sikorsky Alert Service Bulletin No. 76-55-9, Alert Service Bulletin No. 76-55-11, or Customer Service Notice No 76-141B, depending on the specific modification status of the aircraft. Compliance must be achieved within specific intervals post-service, contingent on the bulletin. Notably, the legislation provides for terminating actions for certain bulletins, contingent upon modifications to the aircraft structure. The directive has been updated to reflect changes in compliance requirements for modified helicopters, although it is acknowledged that further improvements in modifications are anticipated by the manufacturer.
Key Provisions
The Civil Aviation Regulations 1998, particularly Part 39 - 105, under the Civil Aviation Safety Authority (CASA) Schedule of Airworthiness Directives, include specific provisions for Sikorsky S-76 Series Helicopters. Specifically, AD/S-76/26 Amendment 1 pertains to the vertical stabiliser pylon leading edge skin (Section 11/85). This legislation applies to all models within the Sikorsky S-76 series. The main requirement outlined in this directive involves adherence to specific Sikorsky bulletins and notices. Operators must comply with either Sikorsky Alert Service Bulletin No. 76-55-9, Sikorsky Alert Service Bulletin No. 76-55-11 (for terminating action), or Sikorsky Customer Service Notice No 76-141B (also for terminating action). Compliance mandates specific inspection intervals; for para. E(1) of ASB 76-55-9, inspections must occur within the next 25 hours of time in service after 25 March 1983 and at intervals not exceeding 25 hours thereafter. For para. E(2) of the same bulletin, inspections should be conducted within the next 100 hours of time in service after 25 March 1983 and at intervals not exceeding 100 hours thereafter.
The obligations and requirements imposed by this Act are clear and specific. Operators and owners of Sikorsky S-76 Series Helicopters must ensure that the vertical stabiliser pylon leading edge skin is inspected according to the stipulated bulletins and notices. This includes conducting the necessary inspections within the specified time frames post-25 March 1983, and adhering to the outlined intervals to maintain compliance. Failure to comply with these directives can lead to significant operational disruptions and safety risks, as the directive addresses potential structural weaknesses in the vertical stabiliser pylon.
In terms of consequences, breaches of these airworthiness directives can result in serious legal and safety implications. Operators who fail to comply with the inspection and maintenance requirements risk facing penalties. While the specific penalties are not detailed in the legislative text provided, they typically include fines and potential grounding of the aircraft until compliance is achieved. Civil aviation regulations often carry stringent measures to ensure adherence, as non-compliance can lead to severe safety hazards. Therefore, operators must take these directives seriously to avoid any legal or safety repercussions.