The preview course pointer will then be removed and the standard course pointer will be slewed to the previewed selected course. When the flight director determines that the capture point for the previewed mode has been reached, it will transition the flight director from LNAV mode to the capture mode of the previewed navigation source. Once the previewed navigation source is valid, if the approach mode (for localizer or ILS) or VOR approach mode (for VOR or TACAN) has been selected on the flight director mode selector, the appropriate LOC, ILS, or NAV annunciator will be illuminated on the EADI.

The preview course deviation bar will respond to VOR, localizer, and TACAN signals as appropriate. Each time the preview course pointer position is changed on the heading dial with the remote course knob, the EHSI digital course display will show the preview course in magenta for 5 seconds, or until the course is changed again. The preview course pointer may be rotated around the heading dial using the remote course knob on the remote instrument control panel, located on the pedestal extension (fig. Selection of V/L or TCN on the display controller after the above two conditions have been met. LNAV is the lateral capture mode (green) displayed on the EADI. The preview course pointer will be displayed if: INS is displayed as the navigation source on the EHSI. A preview course pointer (magenta) is provided to enable the pilot to preview data prior to its use. The aircraft symbol provides a quick visual cue as to the aircraft's position with respect to the selected course and aircraft heading. The to-from annunciator will be removed from view during localizer operation. An arrowhead (white triangular box) in the center of the EHSI indicates whether the selected course is to or from the station or waypoint. GSPD/TTG information is always referenced to the active INS waypoint. Depressing the GSPD/TTG button on the display control panel will cause groundspeed or time-to-go to alternately be displayed. The course deviation bar always indicates the location of the course centerline relative to the nose of the aircraft. When back course (BC) mode has been selected, or when a localizer frequency has been tuned and the selected course is more than 90 degrees from aircraft heading, course deviation will automatically reverse to provide proper deviation sensing with respect to the course centerline.

When the selected navigation source is the INS, each dot represents 3.75 nautical miles of cross track deviation. When the selected navigation source is a localizer, each dot represents a 1 degree deviation from the centerline of the course. When the selected navigation source is a VOR or TACAN station each dot on either side of the aircraft symbol represents a 5 degree deviation from the centerline of the course. The aircraft symbol pictorially shows the aircraft's position in relation to the selected course or track. The course deviation bar represents the centerline of the selected VOR, localizer, or TACAN course, or inertial navigation system (INS) track.

Localizer back course symbol