Hi Ghiby
You started a extremely hard difficulty start up.
Supporting words of Aviator48 . And remarking: there are 3 main things that are draining all your money:
- Monthly maintenance its very high for operation of 1 aircraft. 737-800 could be nice. For me a fleet of 10 aircraft model type are fair to cover the model maintenance base cost. The game have a lot of numbers to get lost. In the plane page you could check how are going the (individual) plane finance. But this its only a part of expenses. Example: Boeing 737 Classic (Base Cost) $3,275,000
- Leasing new most modern planes. For situations of the aircraft industry. New planes are very expensive than older models. So i strongly recommend you to check the market for second hand, older; similar models. For starting. Later when you have a satisfactory profit you can sell them and buy your most wanted plane. As example, Buying the airbus NEOs its not a New Engine Option for me, because are so New Expensive Option. That older models fulfill my profit demands.
- Big airports arent good for a easy starting. Because gate lease are very expensive. Big airplanes could easy cover this value.
As you could imagine. Starting humble in a secondary airport with a 10 older planes, exploited staff. Could give you a starting hand of money. A path to be a strong airline. I hope with months. I recommend you try again.