the adequate distance to view the game...

[Vorondil]

This would effectively transform the monitor to a 'holographic window' for one single user. It would be an awesome party trick, but as mentioned above, it would be unwieldly to use in a flight sim. Using rotating axles to rotate the camera and translating axles to reposition the holo-window might be feasible.

Anyhooo, this calculation should give the proper FoV for an adjustable distance, as long as monitor size and window sizes are known.

FoV = 2 * arctan( MonitorDiameter * cos( arctan(PixelsHeight/PixelsWidth) ) / 2)

This would make the FoV zoom out as you lean forward, giving you a single-user-holo-window.