PLOT PAGES (4 of 9)
APPROACH PLOT
The Approach Plot page consists of three graphs:
- Lateral deviation (distance left/right from the localiser; Y axis scale is dependent on localiser beam width and X axis scale is dependent on Scale button selection)
- Vertical deviation (distance above/below the glideslope; Y axis scale is dependent on glideslope beam width and X axis scale is dependent on Scale button selection)
- Speed (aircraft speed and a reference speed; Y axis scale is 100 to 200 kt, X axis scale is dependent on Scale button selection)
The approach plots are active when the aircraft is in proximity to the active runway. The 'box' limits around the runway are:
- Front: 12 nm
- Back: Runway length
- Side: 7000 ft either side
- Top: 10 000 ft
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:
- Localiser beam width: 4º
- Glideslope beam width: 1.44º
- Glideslope angle: 3º
