If you open a Flight Simulator Bush Trip leg (or the entire Bush Trip) in Flightplan and save it, you are creating a copy of the route the Bush Trip takes, which you can then modify and load through World Map as you would any other free flight.
In order for Flight Simulator to track your progress for a Bush Trip you must fly the Bush Trip from the in-game menu using the exact parameters specified by the Bush Trip. In other words, for Flight Simulator to record your progress you need to fly each leg using the weather, time of day, aircraft, etc. that is defined for the Bush Trip or Flight Simulator will not increment your progress.
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