Fuel Combination:
1. Trip Fuel(T/O, Cruise, Descent, Landing)
2. Alternate Fuel
3. Holding Fuel(Jet:30mins, GA: 45 Mins)
4. Contingency fuel( 15mins, 5%) *Depends on company policy
*Required Fuel = Sum of item 1 - 4
5. Taxi Fuel (400 - 500KG)
6. Extra Fuel (MEL, Loading, NOTAM[Weather], ATC Delay) *Total Fuel = Sum of item 1 - 6