Overview

The Civil Aviation Regulations 1998 (CAR 1998), specifically under PART 39 - 105, include an Airworthiness Directive issued by the Civil Aviation Safety Authority (CASA) to address safety concerns associated with the oil pressure switch in certain Cessna 172R and 172S model aeroplanes. This legislative instrument, AD/CESSNA 170/67, was enacted to mitigate the risk of engine oil failure due to switch diaphragm failures, which could lead to engine power loss. The directive was issued under subregulation 39.1(1) of CAR 1998, requiring inspections and replacements of specified oil pressure switches within a defined timeframe. The policy objective of this directive is to ensure the continued airworthiness of affected aircraft by mandating the replacement of defective components to prevent potential safety hazards. The directive became effective on 8 March 2000, following notification in the Commonwealth of Australia Gazette.

Scope and Application

The Airworthiness Directive issued under Part 39 - 105 of the Civil Aviation Regulations 1998 applies specifically to Cessna 172R and 172S model aeroplanes with certain serial numbers, mandating actions to rectify identified unsafe conditions concerning the oil pressure switch. The directive applies to aeroplanes within the specified serial number ranges, and the required actions must be undertaken by those responsible for the maintenance and operation of these aircraft. This AD is applicable within the Commonwealth of Australia and is enforced by the Civil Aviation Safety Authority (CASA). The directive does not explicitly state any exclusions or exemptions, but it does provide specific thresholds and timelines for compliance, such as inspections within 25 hours time in service and replacement before further flight. The application of this AD may be extended or clarified through subordinate instruments, such as service bulletins or additional CASA communications.

Key Provisions

The Civil Aviation Regulations 1998, under Part 39, specifically Section 105, address Airworthiness Directives concerning various aircraft models. One such directive, AD/CESSNA 170/67, pertains to Cessna 172R and 172S model aeroplanes with specific serial numbers. The directive requires that the oil pressure switch on these aircraft be inspected to determine whether it is part number (P/N) 77041 (or an approved equivalent P/N) or P/N 83278 (or an approved equivalent P/N). If the installed switch is P/N 83278, no further action is required. However, if the switch is P/N 77041, it must be replaced with a P/N 83278 switch. Furthermore, the installation of P/N 77041 switches is prohibited on any aeroplane. The obligations imposed by this directive are clear and precise. Owners and operators of affected Cessna 172R and 172S model aeroplanes must inspect the oil pressure switch within the next 25 hours of time in service from the effective date of the directive, 8 March 2000. If the switch is P/N 77041, it must be replaced before any further flight. Additionally, P/N 77041 switches cannot be installed on any aeroplane as of the directive's effective date. These requirements aim to ensure the continued airworthiness and safety of the affected aircraft by addressing the risk of oil pressure switch failure. Failure to comply with this Airworthiness Directive can result in serious safety implications, potentially leading to engine oil loss and subsequent engine failure. While the regulations do not explicitly state penalties for non-compliance, such failure could lead to aircraft being deemed unairworthy, resulting in grounding of the aircraft. Furthermore, non-compliance could potentially lead to investigations and enforcement actions by the Civil Aviation Safety Authority, which could include fines, sanctions, or other regulatory actions against the aircraft operator or owner. The directive underscores the importance of adhering to safety mandates to prevent hazardous conditions in aviation.