First time to play, have a question: Is plane profitful for freight? I want to build airports in 1975, now I am in 1968. I have 2 M cash, is it enough for a plane? Is there some new type airplane good? I use Pak128.
Hard to say.
1. Build airports to large hubs.
2. 3 millions (as is visible in screenshot you linked to else topic) should be enough
3. Don't wait that they will be full in the first flight.
4. Is plane profitable for freight? Yes - and no. It is based on good you want to transport. If I remember right, most of goods should be profitable.
5. Pay attention to production and consumption. And number of planes. Build as many loading places as you have planes.
It is all I can say at this time.