For 100 hawk flights, you will need 76 fuel for each round. For 100 planes it's 7,600. That's a scaring amount of fuel. A fully working fuel ring will give you 400 fuel per day. So... how it is possible?
400 per day. A week = 2,800
If you have for example 3 Fuel Rings: a week = 8,400.
Plus ask F20 from neighbors everyday 600 fuels minimum (30 gifts), a week = 4,200
Plus all the F20, F50, F150, F300 in warehouse. And don’t forget Fuels in boxes (space boxes, alliance rating boxes, silver chest, etc.)
It’s not that hard, really.