Overview

The Civil Aviation Regulations 1998, specifically under PART 39 - 105, address the issue of ensuring the airworthiness of aircraft by issuing directives on necessary modifications and inspections. The legislative instrument F2006B11157, enacted by the Commonwealth of Australia, targets the Gates Learjet 24 and 25 Series Aeroplanes, issuing an Airworthiness Directive (AD/LEARJET/5) aimed at modifying airspeed-machmeters. This directive mandates that the maximum operating limit speed (Vmo) be clearly marked on the dial of the airspeed-machmeters for certain Learjet models, ensuring compliance with safety standards. The directive applies to specific serial numbers of the Learjet Model 24D and requires these modifications to be completed within 300 hours of the aircraft's time in service following the directive's issuance on 28 June 1974. The policy objective of this regulation is to maintain the highest safety standards in civil aviation by ensuring that all aircraft comply with necessary modifications and operational directives as stipulated by the Civil Aviation Safety Authority.

Scope and Application

The Civil Aviation Regulations 1998, specifically Part 39 - 105, pertains to the modification of airspeed-machmeters on Gates Learjet 24 and 25 series aeroplanes as outlined in the Civil Aviation Safety Authority Schedule of Airworthiness Directives. This legislation applies to Learjet Model 24D with serial numbers 266 and 279.6/74. The requirement is to inspect and, if necessary, modify the airspeed-machmeters to ensure the Vmo limit is clearly marked on the dial. For instruments without coloured sectors, a red radial line at 306 knots must be present, while instruments with coloured sectors should have a red arc extending from 306 knots to 700 knots. Any other limit marks or coloured sectors above 306 knots must be removed. Additionally, arrangements must be made with the Department of Transport to amend the Aircraft Flight Manual to reflect any necessary changes to the aircraft installation. Compliance with these modifications is mandatory within 300 hours of time in service following 28 June 1974. This directive ensures that the airspeed-machmeters adhere to specific safety standards set by the Civil Aviation Safety Authority.

Key Provisions

The main operative sections of the Civil Aviation Regulations 1998, specifically AD/LEARJET/5, pertain to the modification and inspection of airspeed-machmeters on Gates Learjet 24 and 25 series aeroplanes, particularly Model 24D with serial numbers 266 and 279.6/74. According to section (1), the requirement is to inspect and, if necessary, modify the airspeed-machmeters to ensure that the maximum operating limit speed (Vmo) is marked on the dial. This must be done by marking a red radial line at 306 knots for instruments without coloured sectors, or by marking a red arc extending from 306 knots to 700 knots for instruments with coloured sectors. Additionally, any other limit marks or coloured sectors above 306 knots must be removed. The obligations imposed by these regulations are primarily on the aircraft owners and operators of the specified Learjet models. They must ensure that the airspeed-machmeters are inspected and modified as required within 300 hours of time in service after 28 June 1974. Furthermore, if any changes are made to the airspeed-machmeters, the Department of Transport must be informed to amend the Aircraft Flight Manual to reflect these changes. For instruments that match the presentation detailed in the Gates Learjet 24D Flight Manual Page 1-16 FAA-approved 6.25.70 Change 7, this page can be used in the Flight Manual as it already contains the necessary markings. Failure to comply with these airworthiness directives can result in serious consequences. While specific offences and penalties are not detailed in the provided text, non-compliance with airworthiness directives generally can lead to severe civil or criminal penalties under the Civil Aviation Act 1988. This could include fines or, in more severe cases, imprisonment. Additionally, non-compliance may result in the aircraft being grounded until the required modifications are made, thereby affecting the operational readiness and safety of the aircraft. It is imperative for the parties governed by these regulations to adhere strictly to the stipulated requirements to avoid such repercussions.