Properly setting up your computer and Aerofly FS 2 if you intend to use 3 monitors is important for Aerofly to look right and perform well.
If you have 3 monitors connected, and you are using a NVIDIA graphic card, the first thing you should do is enable the NVIDIA Surround mode in the NVIDIA control panel. This way Aerofly FS 2 will recognize all 3 monitors as a single monitor and allow to properly switch to fullscreen mode. So if you have 3 monitors with a resolution of 1920×1080, you will see a new fullscreen mode in Aerofly FS 2 with a resolution of 5760×1080, after activating NVIDIA Surround.
If you want more fine grained control of what each monitor displays, you need to manually edit the Aerofly FS 2 configuration file called 'main.mcf'. main.mcf is located in the folder 'Documents/Aerofly FS 2/'. You can open it with a simple text editor like notepad.
Look for the lines:
Aerofly FS 2 allows you to render a complete view of the simulator to separate parts of the window. So in case of a 3 monitor setup, we want each monitor to receive its own view. If all monitors have the same resolution, insert the following lines between the above two lines:
Each field show be self explanatory. However here is a small overview: