How about
CASA 29/18 — Civil Aviation (Fuel Requirements) Instrument 2018
(3) If, as a result of an in-flight fuel quantity check in accordance with subsection 6 (2), the usable fuel expected to be remaining on arrival at the destination aerodrome is less than the fixed fuel reserve (where no alternate aerodrome is required), then the pilot in command must take appropriate action and proceed to an en-route alternate so as to perform a safe landing with not less than the fixed fuel reserve remaining.
(5) The pilot in command must declare a situation of emergency fuel when the calculated usable fuel predicted to be available upon landing at the nearest aerodrome where a safe landing can be made is less than the fixed fuel reserve for the flight. The pilot in command must declare an emergency fuel state by broadcasting MAYDAY, MAYDAY, MAYDAY FUEL.Table 1 — Fixed fuel reserve and variable fuel reserve requirements
Item
Column 1
Aircraft
Column 2
Flight rules
Column 3
Fixed fuel reserve
Column 4
Variable fuel reserve
Other than RPT and charter
1
Small aeroplane (piston or turboprop)
Day V.F.R.
30 minutes
N/A
2
Small aeroplane (piston or turboprop)
I.F.R. or night V.F.R.
45 minutes
N/A
3
Turbojet or large aeroplane (turboprop)
I.F.R. or V.F.R.
30 minutes
5%
4
Large aeroplane (piston)
I.F.R. or V.F.R.
45 minutes
5%
Not hard to find