This page is selectable from the Plots tab suite and consists of three graphs:
The approach plots are active when the aircraft is in proximity to the active runway. The 'box' limits around the runway are:
The 'zero' point on the graphs is the latitude and longitude co-ordinate of the glideslope beam as defined in the Navigation Data, offset laterally to be on the runway centreline.
The localiser beam width and glideslope beam width and angle are obtained from the Navigation Data. If no data exists, the following defaults are used:
By default, the localiser and glideslope beams are displayed with deviation lines at 1 and 2 dots either side of the beam centreline.
By default, the localiser and glideslope lines flash when the aircraft is within the proximity `box' (4Nm) of the active runway but outside of the glideslope beam.
The plots are erased under the following conditions:
The lateral and vertical deviation graphs display a vertical yellow bar across the plot as an 'incident' marker. This is displayed when any malfunction is activated while these plots are active. The position of the marker is determined by the aircraft position at the time of the incident.
The position of Approach Landing Markers are displayed graphically (as cones) on the vertical deviation graph. The localiser and glideslope beams and the approach marker cones are displayed in red if the associated radio navigation stations are failed.