AD/CESSNA 170/6 Amdt 2 - Undercarriage Attachment Bolts

Overview

The Civil Aviation Regulations 1998, specifically in Part 39 - 105, detail the Civil Aviation Safety Authority's (CASA) Schedule of Airworthiness Directives, addressing safety concerns in the aviation industry. The regulations were enacted to ensure the highest safety standards and compliance with international aviation safety protocols. One such directive, AD/CESSNA 170/6 Amendment 2, pertains to Cessna 170, 172, F172, FR172 and 175 series aeroplanes, focusing on the critical requirement to replace undercarriage attachment bolts. This amendment was introduced to mitigate risks associated with the undercarriage system's structural integrity, ensuring that bolts and nuts attaching the inboard end of the undercarriage spring legs are replaced at regular intervals to prevent potential failures. CASA mandates these changes to enhance aircraft safety, aiming to prevent any in-flight incidents that could result from compromised undercarriage attachments.

Scope and Application

The Civil Aviation Regulations 1998, specifically Part 39 - 105, addresses the Airworthiness Directives concerning various series of Cessna aeroplanes, including the 170, 172, F172, FR172, and 175. This legislation applies to the specified models within these series, mandating that the undercarriage attachment bolts be removed and replaced with new ones at specified intervals to ensure compliance with airworthiness standards. The geographic reach of these regulations is national, applying across the Commonwealth of Australia, thereby affecting all operators and owners of the specified Cessna aeroplanes within the country. The regulations do not specify exclusions or exemptions for particular entities or industries, but they do set a clear compliance threshold based on the operational hours of the aircraft. The application of these directives is also extendable or restrictable through subordinate instruments, allowing for adjustments in response to evolving safety standards or operational realities.

Key Provisions

The Civil Aviation Regulations 1998, specifically under Part 39 - 105 (section 39.105), detail the Civil Aviation Safety Authority's (CASA) Schedule of Airworthiness Directives. One such directive, AD/CESSNA 170/6 Amendment 2, pertains to the undercarriage attachment bolts of Cessna 170, 172, F172, FR172, and 175 series aeroplanes. This directive applies to models 170, 170A, and 170B (section 39.105(1)). The primary requirement is that the AN7-20A bolts and nuts attaching the inboard end of the undercarriage spring legs must be removed and replaced with new AN7-20A bolts and new nuts (section 39.105(2)). These obligations impose clear duties on aircraft operators and maintenance personnel. They must ensure that the specified bolts and nuts are replaced at intervals not exceeding 500 hours of time in service (section 39.105(3)). For aircraft that have already exceeded 500 hours of time in service since the last replacement, compliance must occur within 100 hours of time in service after 30 November 1971, and then as per the stipulated intervals (section 39.105(4)). Failure to comply with these airworthiness directives can result in significant consequences. The regulations set out in the Civil Aviation Regulations 1998 impose penalties for non-compliance. Violation of these airworthiness directives may lead to enforcement actions, which can include fines and other sanctions (section 39.105(5)). In severe cases, the aircraft may be grounded until the required maintenance is performed, potentially leading to substantial operational disruptions for the operator. Additionally, continuous non-compliance can result in more serious consequences, including potential prosecution under civil aviation laws, which could lead to imprisonment or heavier fines depending on the severity of the breach (section 39.105(6)). Therefore, adherence to these provisions is crucial for maintaining the safety and airworthiness of the aircraft.