There is always something to improve for my model airport beside adding new airplane or airlines to my airport. The thing that I am looking forward to add to my airport currently is to add sky train. Most of the international airport have this sky train service to help passengers move from one terminal to another terminal. This will going to be helpful to passenger if the airport have more that one terminal because it help passenger move faster from one gate to another to connect their flights if passengers were required to change plane or airlines to reach their final destination. For my airport I just want the  sky train service to connect my main terminal to both satelite terminal. It can be seen on the roof top of the main terminal but will go underground when it reach the taxiway. So it just required 2 short tracks dividing the centre of the main terminal while the remaining of the tracks to the satelite buiding will be underground. This is still in the planning stage and hopefully it will be a sky train in the future for my model airport. There are some accessories from Herpa that can help me to achieve my plan. There are 520119, 520126, 520133, 520140 but I don't required all of this..just some.