Operational Navigation
Systems Navigation
SEQUENTIAL STEERING
The sequential steering string (Figure 5) is displayed as dashed lines on the HSI when two or more
waypoints have been entered and SEQ is selected. The dashed lines are displayed to the edge of
the active MFD display area, including the area outside the compass rose, as determined by the
selected HSI scale.
WAYPOINT SYMBOL
The waypoint symbol is a circle with a dot in the middle (Figure 5). Waypoint 0 has a unique symbol
shaped like a baseball home plate. The waypoint number is displayed just to the right of the
waypoint symbol. Only the "selected" waypoint symbol is displayed, and then only if the distance to
the waypoint is less than the selected HSI compass rose scale.
WAYPOINT OFFSET SYMBOL
If the selected waypoint has a valid offset entered, the waypoint offset symbol, a plus sign (Figure 5),
and WO/S legend are displayed. An offset symbol is not displayed if the compass rose scale is less
than the distance to the waypoint offset. When offset steering is selected and a new waypoint is
selected, manually or automatically, offset steering is automatically deselected and waypoint steering
is selected.
WAYPOINT DATA
The waypoint data block (Figure 5) displays bearing, distance, time-to-go and the waypoint identifier.
The time-to-go is calculated using the current ground speed and actual distance to the selected
waypoint or waypoint offset. A change in heading will change ground speed, therefore time-to-go is
only accurate to waypoints on the nose of the aircraft. When CRS is selected on the HSI, the
bearing to the selected waypoint or waypoint offset is shown on the HUD by the course deviation
situation steering arrow. The distance, time-to-go and selected steering mode are shown on the
right side of the HUD below the barometric altitude block.
Waypoints
On start, the ten active tactical waypoints from the last flight are retained in the display system.
There are a maximum of ten active waypoints plus waypoint zero. Waypoint zero is distinguished
from other waypoints because it is used for the GPS/INS alignment and is not normally used for a
navigation point except for returning to home field. Changing waypoint zero prior to a full alignment
will delay the alignment as the system resolves any difference between the location of the pilot
entered waypoint zero and the actual location of the aircraft. Waypoint data in the system can be
changed in two ways:
(1) transferring waypoint data from one of 200 waypoints in the mission data loader (GPS
option) or
(2) manually changing the latitude, longitude, elevation and/or magnetic variation of a tactical
waypoint (WYPT option).
(4-03) Original
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