AD/G159/39 - Flight Manual - Change to Metric Units

Overview

The Civil Aviation Order (CAO) 1988, established by the Australian Government through the Civil Aviation Authority Act 1988, governs the safety and efficiency of civil aviation within Australia. One of the key legislative instruments under this framework is the Civil Aviation Order 1988 Part 105 Schedule of Airworthiness Directives, which includes AD/G159/39 regarding the Gulfstream (Grumman) G159 Series aeroplanes. This directive was introduced to address the need for harmonisation of measurement units in the aviation sector, ensuring consistency with the international metric system and aligning with Australian standards for aircraft operation. The Civil Aviation Safety Authority (CASA) is the enacting body responsible for ensuring compliance with these orders, with a clear policy objective to enhance safety and uniformity in aviation practices across the country. AD/G159/39 specifically mandates the conversion of all specified quantities in the flight manual of Grumman G159 Series aeroplanes to metric units. This includes changing weight to kilograms, distances to metres, centre of gravity limits and moment arms to millimetres, fuel and oil quantities to litres, and pressures to kilopascals. If the aircraft's installed instrumentation uses different units, both systems must be specified in the manual. The compliance deadline for these changes was set for 1 January 1984, reflecting a broader effort to standardise aviation documentation in line with international practices and enhance operational safety.

Scope and Application

The Civil Aviation Orders, specifically Part 105 Schedule of Airworthiness Directives, applies to all Grumman G159 Series Aeroplanes operated within Australia. The directive mandates that the Department of Transport approved flight manual for these aeroplanes must be updated to reflect metric units for various specifications such as weight, distances, centre of gravity, fuel and oil quantities, and pressures. This requirement ensures consistency with Australian standards for airworthiness and operational data, thereby enhancing safety and compliance for these aircraft. Should the installed aircraft instrumentation be calibrated in non-metric units, the flight manual must detail both metric and non-metric systems. The directive mandates compliance by 1 January 1984, with the aim of standardising the use of metric units in the aviation sector. This Act does not specify exclusions, exemptions, or thresholds, and its implementation may be further refined or extended through subordinate instruments as needed.

Key Provisions

The main operative sections of the Civil Aviation Orders (CAO) 1988, as amended, pertain to Airworthiness Directives (AD) for specific aircraft models, including the Gulfstream (Grumman) G159 Series Aeroplanes. Section AD/G159/39 specifically mandates changes to the flight manual to ensure all specified quantities are provided in metric units (Section 1). The directive requires the Department of Transport (DoT) approved flight manual to detail weight in kilograms (a), distances in metres (b), centre of gravity limits and moment arms in millimetres (c), fuel and oil quantities in litres (d), and pressures in kilopascals (e). If the aircraft's installed instrumentation is calibrated in non-metric units, the flight manual must specify both metric and non-metric systems (Section 2). The compliance date for these changes is set for 1 January 1984 (Section 3). The Act imposes several obligations on the parties and entities it governs. Firstly, it mandates that the flight manual for the Grumman G159 Series Aeroplanes be amended to include all specified quantities in metric units. This includes ensuring that any existing non-metric instrumentation readings are also clearly noted in the flight manual. The requirement applies to all aircraft within the specified series, ensuring uniformity and clarity in operational data and airworthiness limitations. Compliance with these changes is mandatory, with a clear deadline of 1 January 1984. The Act also includes provisions for civil and criminal consequences for non-compliance. Failure to amend the flight manual as required by the directive may result in the aircraft being deemed non-compliant with airworthiness standards. Such non-compliance could lead to grounding of the aircraft until the necessary changes are implemented. The specific penalties for non-compliance are not detailed in the text, but typically, such failures could result in fines, operational restrictions, or other administrative penalties imposed by the Civil Aviation Safety Authority (CASA). Additionally, the directive highlights the importance of maintaining accurate and up-to-date operational data for the safety and efficiency of aircraft operations. By mandating metric units, the Act aims to standardise operational practices across the aviation sector, reducing confusion and potential errors that could arise from mixed units of measurement. This standardisation is crucial for ensuring that pilots and maintenance personnel have consistent and accurate information, thereby enhancing overall aviation safety. In conclusion, AD/G159/39 is a critical directive under the CAO 1988, ensuring that all Grumman G159 Series Aeroplanes adhere to specified metric standards in their flight manuals. Compliance with this directive is mandatory, with significant implications for non-compliance, including potential grounding of aircraft and other enforcement actions by CASA. The directive underscores the importance of standardised operational data in maintaining high safety standards in Australian aviation.