[CarstenB]

Aus der Doku zum GPS(Sorry, ich habe die engl. Version)

The Nav/GPS Switch

Flight Simulator aircraft featuring the GPS 500 (as well as the Bell 206B JetRanger III and the Extra 300S) have a Nav/GPS switch on the instrument panel:
When the switch is in the Nav position, the aircraft's VOR 1 indicator (or HSI) and autopilot/flight director use data from the Nav 1 radio.
When the switch is in the GPS position, the aircraft's VOR 1 indicator (or HSI) and autopilot/flight director use data from the GPS receiver.

Note: To couple the GPS to the Nav 1 receiver (or HSI) and/or to the autopilot/flight director in order to follow the course in the GPS, set the Nav/GPS switch to GPS. Note that the GPS only provides lateral guidance to the Nav 1 indicator (or HSI) and the autopilot/flight director. You cannot fly an ILS or land automatically using the GPS as the sole source of navigational data.

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Active Flight Plan Page

If you create a VFR or IFR flight plan using the Flight Planner, Flight Simulator will automatically load the flight plan into the GPS and activate the plan for use in navigation. (For more information, see Using the Flight Planner.)

The Active Flight Plan page provides information for the active flight plan (or direct-to).

To select the Active Flight Plan page
Press the FPL button.

Note: You cannot create flight plans in the Flight Simulator GPS. Instead, use the Flight Simulator Flight Planner. The flight plan will automatically be loaded into the GPS and activated for use. You can, however create a "direct-to" to a destination.