The GPS used in the twin Otter extended is based on the default FSX GPS 500, but has been tweaked to resemble the Garmin GNS530, which also includes the Com1 and Nav1 radios as well as DME readouts and current radial on which the aircraft is situated. For the GPS part please refer to the FSX description of its use, found in FSX's build-in Learning centre.
On the left and lower part of the GPS the following functions can be found:
• C rocker button (left click) - Swaps the active and standby Com1 frequency.
• V rocker button (left click) -Swaps the active and standby Nav1 frequency.
• C knob (left click) - GPS power - Turn On/Off the GPS unit.
• V knob (left click) - Nav1 Ident On/Off.
• Inner (large) Com/Vloc knob (mouse wheel) - Sets the integer frequencies of Com1 or Nav1 radios.
• Outer (small) Com/Vloc knob (mouse wheel) - Sets the decimal frequencies of Com1 or Nav1 radios.
• Outer (small) Com/Vloc knob (left click) - Selects between setting Com1 of Nav1 radio.
• CDI button (left click) - Selects the source for the autopilot and HSI between Nav1or GPS.
• OBS button (left click) - Toggles Suspend mode on/off (automatic change to next waypoint)
• MSG button (left click and hold) - will turn off messages (standard FSX default message box) as well as the reminder box to set the OBS course.
Flight plans can be loaded via FSX own flight planner menu. Flight plans can also be generated by 3rd party flight planner, like FS Commander 9, FSBuild etc.... and then loaded via the FSX flight planner menu. When a flight plan has been loaded the GPS might look like this:
When the GPS changes to the next waypoint, the following will be prompted on the display:
Manually set the HSI Course to the setting shown. The HSI will now give the correct indications in order to
follow the flight plan leg.