The DC-9 Classic comes with these 6 liveries in the release package:
The Flight Center is the starting point for all aircraft administration, dispatch, options, training and failure simulation. You can also access the Navigation Simulator and the live schematic system views from the Flight Center.
What exactly is radio navigation? In short, radio navigation is the art of locating your position on the earth by use of radio waves. Radio waves can be used to find direction (bearing), distance (ranging) and also velocity to or from a station.