Hard to tell from Yearly data....
But, it looks to me like Maintenance is killing you.
You're spending as much on Maintenance as you are on Leases. That's crazy. I spend about 1/4th as much on Maintenance as I do on Leases.
I try to keep my maintenance costs between 5-10% of my Revenues (and 10% is high, only good for when you need lots of mismatched planes to expand). Yours are a whopping 25% of your revenues.
Looks to me like you've spent as much on maintenance already in 2000 as you did in 1999, but have only earned HALF the money so far. So you've done something to create a massive increase in your maintenance costs this year over last (could be C-Check timing, hard to say with looking at just one screen).
So you either have too many plane-types, too many engine-types (not as much of a factor), OR you're buying planes that have big maintenance checks due and you're spending lots of money on doing maintenance checks as soon as you buy the plane.
I'm betting it's the Plane-Types. You say 3, but are you talking about 1, and 1, and 1? Or 50 of one, 25 of another, and 3 of another? (I can't see your fleet as I'm not playing ATB) It makes a big difference. If you've only got 5 planes and they're all different, you're going to have some pretty massive fixed costs that you won't be able to overcome.