AD/CESSNA 500/22 - Brake Shuttle Valve

Overview

The Civil Aviation Regulations 1998, as amended by the legislative instrument F2006B08397, address the issue of brake shuttle valve failures in certain Cessna 500 (Citation) Series aeroplanes. This legislative instrument was enacted to ensure the airworthiness of these aircraft by addressing a specific safety concern identified in the operation of the affected models. The policy objective behind these regulations is to mandate regular inspections and replacements of the brake shuttle valves to prevent potential failures that could compromise flight safety. These measures are overseen by the Civil Aviation Safety Authority, which is tasked with ensuring compliance to mitigate any risks associated with the identified problem. The instrument specifically targets models 500 and 501 of the Cessna 500 series with unit numbers from -0001 through -0689, which were equipped with BF Goodrich brakes and wheels installation. The requirement is to inspect and replace the brake shuttle valves in accordance with manufacturer guidelines to address the issue of valve leakage, which has been linked to the deterioration of the shuttle valve o-ring material due to exposure to an incompatible seal lubricant. The inspections must be carried out within specific intervals post-service hours to ensure ongoing safety.

Scope and Application

The Civil Aviation Regulations 1998, specifically Part 39 - 105, governs the airworthiness directives issued by the Civil Aviation Safety Authority, which are crucial for ensuring the safety of aircraft operations in Australia. Within this framework, AD/CESSNA 500/22 pertains to the inspection and replacement of brake shuttle valves in Cessna 500 (Citation) Series Aeroplanes, particularly models 500 and 501 with unit numbers -0001 through -0689 that incorporate Service Bulletin 32-38 and feature BF Goodrich brakes and wheels. This directive applies to aircraft within the Commonwealth of Australia, affecting both private and commercial operators of the specified aircraft models. Compliance with these directives is mandatory, requiring inspections as per Cessna Alert Service Letter SLA 500-32-46 and replacement of the shuttle valves in line with BF Goodrich Service Bulletin SB 517. The inspection must occur within 50 hours of time in service following 17 May 1990 and at intervals not exceeding 50 hours thereafter, until BF Goodrich SB 517 is implemented. The replacement is mandated within 200 hours of time in service after 17 May 1990. The directive is essential to mitigate the risk of brake system failures due to the degradation of shuttle valve o-ring material caused by exposure to an incompatible seal lubricant, as reported by the manufacturer.

Key Provisions

The Civil Aviation Regulations 1998, specifically Part 39 - 105, includes a schedule of Airworthiness Directives (AD) pertaining to various aircraft types, including the Cessna 500 (Citation) series aeroplanes. One such directive, AD/CESSNA 500/22, addresses the brake shuttle valve for models 500 and 501 with unit numbers -0001 through -0689 that have incorporated Service Bulletin 32-38, BF Goodrich brakes, and wheels installation (Section 1). The directive mandates inspections and replacements of brake shuttle valves to mitigate the risk of leakage, which has been reported due to deterioration of the o-ring material caused by exposure to an incompatible seal lubricant (Section 2). Compliance with AD/CESSNA 500/22 requires operators to inspect the brake shuttle valves in accordance with Cessna Alert Service Letter SLA 500-32-46. These inspections must occur within 50 hours of time in service following 17 May 1990 and subsequently at intervals not exceeding 50 hours of time in service until BF Goodrich Service Bulletin SB 517 is incorporated (Section 1). Additionally, operators must replace the brake shuttle valves in accordance with BF Goodrich Service Bulletin SB 517 within 200 hours of time in service following 17 May 1990 (Section 2). These measures ensure that the shuttle valves are maintained in a safe and operational condition to prevent potential leakage and associated safety risks. Operators of the affected Cessna 500 and 501 models must adhere to the inspection and replacement requirements set forth in AD/CESSNA 500/22. Failure to comply with these directives could result in non-compliance with the Civil Aviation Regulations 1998, leading to potential safety hazards and operational disruptions. It is imperative that operators maintain meticulous records of inspections and replacements to demonstrate adherence to the regulatory requirements. Any deviation from these requirements could lead to enforcement actions by the Civil Aviation Safety Authority (CASA). Failure to comply with the provisions of AD/CESSNA 500/22 can result in significant consequences. Operators who do not adhere to the inspection and replacement schedules may face enforcement actions by CASA, including fines, operational restrictions, or even grounding of the affected aircraft. The Civil Aviation Regulations 1998 do not specify maximum penalties for breaches of ADs; however, the severity of the consequences will depend on the extent of non-compliance and the associated safety risks. It is crucial for operators to ensure strict compliance to avoid any adverse outcomes.