Hey,
I'd suggest that having 600million cash on hand when you are only getting 6million profit from routes per hour is quite extravagant/lazy... it means not doing anything with your money for over 100 hours (more than 4 days), which makes no sense, especially because an airline with only 6million profit from routes per hour should still have ample opportunity for aggressive expansion.
I'd suggest that a more rewarding strategy would have been to do something such as:
(1) Look at bank balance of 120 million or so when you get online.
(2) Order aircraft so that you have about 1 million on hand.
(3) Look at the aircraft you have with unused hours.
(4) Rent gates at your hubs so that you can assign all of these planes to routes. (This is because you can go only slightly in the red when buying more than 1 gate at an airport.)
(5) By this time you will be negative. Continue going negative with the single "OCP" purchase of destinations and assignment of planes.
(6) By the end of this, you might be in the red for 20 or 30 million, but you will have increased your profit from routes per hour by a million or two.
That means 24-48 million more when you log on the next day to do it again (and for the indefinite future, since you now are pulling down 7-8 million instead of 6).
(Apologies for resurrecting a semi-moribund thread...)