4TAKEOFF TOUR190-00356-00 Rev GKey and Knob FunctionsBottom Row KeysThe nearest (NRST) key (400W/420Wonly) displays the nearest airports page.Then, turning the small right knob stepsthrough the NRST pages.The CDI key (430W only) is used to togglewhich navigation source (GPS or VLOC) pro-vides output to an external HSI or CDI.The OBS key is used to select manual orautomatic sequencing of waypoints. Pressingthe OBS key selects OBS mode, which willretain the current “active to” waypoint asyour navigation reference even after pass-ing the waypoint (i.e., prevents sequencingto the next waypoint). Pressing the OBSkey again will return to normal operation,with automatic sequencing of waypoints.Whenever OBS mode is selected, you may setthe desired course to/from a waypoint usingthe OBS Page, or an external OBS selector onyour HSI or CDI.The message key (MSG) is used to viewsystem messages and important warnings andrequirements. See Sections 11 and 9 for moreinformation on messages and unit settings.The flight plan key (FPL) allows you tocreate, edit, activate and invert flight plans,as well as access approaches, departures andarrivals. A closest point to flight plan featureis also available from the flight plan key. SeeSection 4 for more information on flightplans.COFMPN GPS 400W / GNC 420WGNS 430WThe procedures key (PROC) allows you toselect and remove approaches, departuresand arrivals from your flight plan. Whenusing a flight plan, available procedures foryour departure and/or arrival airport areoffered automatically. Otherwise, you mayselect the desired airport, then the desiredprocedure.Whenever the 400W-series unit is dis-playing a list of information that is toolong for the display screen, a scroll barwill appear along the right-hand sideof the display. The scroll bar graphicallyindicates the number of additional itemsavailable within the selected category.Simply press the small right knob toactivate the cursor and turn the largeright knob to scroll through the list.}scroll bar
