You can save state like fuel, load, all of your switch settings and position by using the flight recorder provided in the game. If you do your flight, land at an airport (or anywhere for that matter) and shut down your aircraft. Then open the flight recorder and record for a few seconds. Stop it and save. You can get out of the sim at this time. When you want to go back to that particular save state, select the same plane in free flight. Then start a flight somewhere near where you saved (you might be able to do this from anywhere in the world, but I haven’t tried it).
At this point you will be outside of the aircraft to do your pre flight check. Get in the aircraft.
Now, open the flight recorder and load your previous save. I think there is a button that says “take control” or something like that. You can hit that button it will warp you into your previously saved aircraft in the exact same state as you left it. You can continue on your adventure.
In fact, you can actually save your state IN FLIGHT using this method. So if you are 4 hours into an 8 hour flight and need a break, try the same method and you can pick up later in mid-air.