I'm in 1976, and I am 5th place in server. Last night I was 3rd, but somehow my monthly profits went from 270,000K down to -412,000K overnight. I then used my last resort (credits) and bought lots of fuel depots and maintenance and airports to cover my expenses, but that only got the profit back up to -10,000K. So then I returned all my leased planes and bought the same planes. That got me up to 4th place, with monthly profits of 100,000 only. So I replaced every plane on routes less than 7,000km with Concordes, and sold all my B747-100s and replaced them with the -200s. My profits skyrocketed. Why did this happen?