COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY
SCHEDULE OF AIRWORTHINESS DIRECTIVES
Ayres Thrush (Snow) Commander Series Aeroplanes
AD/AC-SNOW/23 Vertical Fin Rear Spar 10/95
Applicability: All aircraft with model and serial number listed in Ayres Corporation Service Bulletin SB-AG-38.
Requirement: Visually inspect the vertical fin rear spar for cracks at the upper, centre and lower rudder hinge bearing mounts.
Compliance: Initially inspect before 100 hours’ time in service after 14 September 1995. Re-inspect at intervals not to exceed 100 hours.
Modification in accordance with Ayres Corporation Service Bulletin SB-AG-38 or a scheme accepted by the Authority cancels the Requirement of this Directive.
Background: When installing the modification of Ayres Corporation Service Bulletin SB-AG-38 on one aircraft the vertical fin rear spar was found to be cracked in several locations.
The cracks may be aggravated by internal corrosion of the bearings restricting free movement.
Overview
The Civil Aviation Regulations 1998, administered by the Civil Aviation Safety Authority (CASA), include specific provisions to ensure the safety of aircraft operations. One such regulation is the Airworthiness Directive AD/AC-SNOW/23, which was introduced to address the identified safety issue with the vertical fin rear spar of Ayres Thrush (Snow) Commander Series Aeroplanes. This directive was enacted in response to a discovered crack in the vertical fin rear spar during the installation of modifications outlined in Ayres Corporation Service Bulletin SB-AG-38, which potentially could be exacerbated by internal corrosion of the bearings. The primary objective of this directive is to ensure ongoing airworthiness by requiring visual inspections at specified intervals to detect and address any structural issues promptly, thereby enhancing flight safety.
The directive mandates an initial inspection before 100 hours of time in service post 14 September 1995, followed by subsequent inspections at intervals not exceeding 100 hours. Compliance with the Ayres Corporation Service Bulletin SB-AG-38 modification or an alternative scheme accepted by CASA can fulfil the requirement of this directive, ensuring that any identified structural vulnerabilities are appropriately managed.
Scope and Application
The Civil Aviation Regulations 1998, under Part 39 - 105, mandates the application of Airworthiness Directives concerning specific aircraft models to ensure ongoing safety and airworthiness. This particular legislative instrument pertains to Ayres Thrush (Snow) Commander Series Aeroplanes, specifically targeting the vertical fin rear spar of aircraft with model and serial numbers listed in Ayres Corporation Service Bulletin SB-AG-38. The directive applies to all such aircraft and necessitates a visual inspection of the vertical fin rear spar for cracks at the upper, centre, and lower rudder hinge bearing mounts. The requirement involves an initial inspection before 100 hours’ time in service after 14 September 1995, with subsequent inspections to be conducted at intervals not exceeding 100 hours. Compliance can be achieved through the modification outlined in Ayres Corporation Service Bulletin SB-AG-38 or an alternative scheme accepted by the Civil Aviation Safety Authority. This legislative instrument extends to the Commonwealth jurisdiction, ensuring that all relevant aircraft within Australia must adhere to these safety directives to maintain their airworthiness certification.
Key Provisions
The Civil Aviation Safety Authority has issued an Airworthiness Directive (AD/AC-SNOW/23) for Ayres Thrush (Snow) Commander Series Aeroplanes, which includes specific requirements and obligations for the vertical fin rear spar. According to Section 39-105 of the Civil Aviation Regulations 1998, the directive applies to all aircraft with a model and serial number listed in Ayres Corporation Service Bulletin SB-AG-38. The main requirement (Section 10/95) is a visual inspection of the vertical fin rear spar for cracks at the upper, centre, and lower rudder hinge bearing mounts. This inspection must be conducted initially before 100 hours of time in service after 14 September 1995 and then at intervals not exceeding 100 hours thereafter.
The directive imposes several obligations on the operators and owners of affected aircraft. Firstly, they must ensure that the initial inspection is completed within the specified timeframe. Secondly, they need to maintain a schedule for subsequent inspections at intervals of no more than 100 hours. Additionally, operators and owners must follow the modification guidelines provided in Ayres Corporation Service Bulletin SB-AG-38 or any alternative scheme that is accepted by the Civil Aviation Safety Authority. Failure to comply with these requirements can result in the aircraft being deemed unairworthy.
Failure to adhere to the requirements of the Airworthiness Directive can lead to various consequences. Section 39-105 of the Civil Aviation Regulations 1998 stipulates that non-compliance can result in both civil and criminal penalties. Civil penalties may include fines, and in severe cases, the aircraft may be grounded until compliance is achieved. Criminal penalties can apply if the breach is deemed to have caused significant risk to aviation safety, potentially resulting in imprisonment for the responsible parties. The exact penalties depend on the severity and intent behind the breach but highlight the seriousness with which the Civil Aviation Safety Authority treats compliance with airworthiness directives.