Overview

The Civil Aviation Regulations 1998, amended by the instrument F2006B11146, introduces specific airworthiness directives concerning the Gates Learjet 24 and 25 series aeroplanes. This legislative instrument was enacted to address a critical safety issue identified by the manufacturer regarding the aileron trim tab balance weight on these aircraft models. The problem identified was that the existing balance weight was insufficient to meet failsafe design requirements, potentially leading to flutter in the event of a disconnect in the trim tab system. The instrument was introduced by the Australian Government, through the Civil Aviation Safety Authority (CASA), to ensure compliance with necessary safety standards to protect passengers and crew. The policy objective behind this amendment is to mandate timely replacement of the aileron trim tab balance weight, ensuring the continued airworthiness and safety of the affected aircraft.

Scope and Application

The Civil Aviation Regulations 1998, specifically Part 39 - 105, under the authority of the Civil Aviation Safety Authority (CASA), pertain to the airworthiness directives for certain aircraft. This legislation applies directly to the Gates Learjet 24 and 25 Series aeroplanes, identified by specific serial numbers outlined in the requirement document. The directive mandates compliance for all affected aircraft within 600 hours of time in service after 31 December 1984, or the next aileron/trim tab removal or rebalance, whichever comes first. The regulation is necessitated by a determination from the manufacturer that the aileron trim tab balance weight does not meet failsafe design requirements, thereby preventing possible flutter in the event of a disconnect in the trim tab system. The directive references FAA AD 84-19-06, indicating alignment with international safety standards. This regulation applies to aircraft operating within Australia and adheres to CASA's standards, ensuring that the modifications are implemented to maintain airworthiness and safety.

Key Provisions

The Civil Aviation Regulations 1998, under Part 39 - 105, establish specific Airworthiness Directives (AD) for ensuring the safety and airworthiness of aircraft. Specifically, AD/LEARJET/29 pertains to the Gates Learjet 24 & 25 Series Aeroplanes and mandates the replacement of the aileron trim tab balance weight (Section 39 - 105). This directive applies to all model Learjets with specific serial numbers as detailed in the Requirement Document (Section 39 - 105). The requirement necessitates the replacement of the aileron trim tab balance weight using Gates Learjet AMK 83-3, as referenced in FAA AD 84-19-06 (Section 39 - 105). Compliance with this directive is mandatory within 600 hours of time in service after 31 December 1984, or the next removal or rebalance of the aileron/trim tab, whichever comes first (Section 39 - 105). The background information provided explains that the manufacturer has identified the insufficiency of the aileron trim tab balance weight in meeting failsafe design requirements, which could potentially lead to flutter if the trim tab system disconnects (Section 39 - 105). The obligations imposed by this directive require aircraft operators to ensure that the specified aileron trim tab balance weight replacement is carried out within the stipulated timeframe. Aircraft operators must verify the serial numbers of their Learjet aircraft against the Requirement Document to determine applicability and must use the specified Gates Learjet AMK 83-3 for the replacement. It is also necessary to keep records of the compliance dates and any work performed to address this directive. Operators must ensure that the required maintenance is completed by a certified technician who is knowledgeable about the specific modifications and safety requirements outlined in the directive (Section 39 - 105). Failure to comply with the AD/LEARJET/29 could result in serious safety concerns, including the risk of flutter, which could compromise the aircraft's stability and safety during flight. The regulations do not explicitly state penalties for non-compliance within the provided text, but non-compliance with airworthiness directives can result in severe consequences, including potential grounding of the aircraft, fines, and other enforcement actions by the Civil Aviation Safety Authority (CASA). The severity of penalties can depend on the extent of non-compliance and any resulting incidents or accidents. Operators must be vigilant in adhering to these directives to maintain the highest safety standards and avoid legal repercussions (Section 39 - 105).