I had an airline made completely of EMB120-ER in the MT#8, based in a smaller domestic-only airport in Japan. I joined the game very late, but the airline was very profitable. By the time I bk'ed to move to MT#9 I had 30 a/c, 26 of which owned. My biggest problem was that, joining late in the game, it wasn't possible to buy any new a/c and the few used ones were extremely old. A part from this, it was very easy to be profitable even with the huge personnel costs. My airport even had a 7-20 opening time window and, by packing the flights in such a way that they left at the earliest possible time (e.g. 0700 when all slots were still available) and landed at the latest possible time (1955), I managed to make good money. Also, I didn't run any marketing until later in the process (I think I started buying marketing when I started buying back the leases) but it didn't even matter has I had almost no competition on the routes.