COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES Gates Learjet 24 & 25 Series Aeroplanes AD/LEARJET/26 Flight Manual - Change To Metric Units 9/81 Applicability: All Gates Learjet 24D and 25C series aeroplanes. Requirement: The D.o.T. approved flight manual shall be amended to specify quantities in the following units; (a) weight in kilograms, (b) distances in metres, (c) centre of gravity limits and moment arms in millimetres, (d) fuel and oil quantities in litres, and (e) pressures in kilopascals. Where the installed aircraft instrumentation is calibrated in units other than the above the flight manual shall specify both systems of units. Compliance: By 1 January 1984. Background: It is required that all Australian aircraft be provided with airworthiness limitations and operational data in the declared metric units.