route between two other waypoints in the flight plan.
The point where the reference waypoint lies on the
great circle route is the point where the route passes
closest to a pilot-designated point. Refer to Figure
The waypoint that is used to create the
published or user database. This waypoint
must be located relative to the flight plan
such that it is possible to draw a
perpendicular line from this waypoint to a
segment of the flight plan.
Figure 3-103. Pilot Designated Point
1. Select the reference waypoint page (REF)
on the right side, Figure 3-104. If a flight
plan page is not displayed on the left side,
DESIRED - FPL ON - LEFT PAGE."
E N R - L E G
Figure 3-104. Reference Waypoint
2. Display the desired flight plan on the left
side. The reference feature may be used
on the active flight plan or on any of the 25
numbered flight plans that contain at least
3. Press the right CRSR button to turn on the
right cursor function.
4. Use the RIGHT INNER and outer knobs to
enter the identifier of the desired waypoint,
E N T
ENR - LEG
Figure 3-105. Desired Waypoint
5. Press the ENT button to display the
waypoint page for the waypoint just
6. Press the ENT button again to display the
waypoint page for the newly created
reference waypoint. The waypoint that
was used to create the reference waypoint
is automatically inserted into the REF field.
The radial and distance as well as the
latitude and longitude are also displayed.
The left side of the screen shows where
the reference waypoint will be inserted in
the flight plan.
The KLN 90B automatically names the reference
waypoint by appending the first available alphabetic
character to the identifier of the waypoint used to
define the reference waypoint. TXK becomes TXKA,
etc. Refer to Figure 3-106. If TXK is used again to
create a second reference waypoint in another flight
plan, this second reference waypoint would be named
TXKB. If a reference waypoint is created using a
waypoint with a five-character identifier, the fifth
character will be dropped, e.g., DUSTT becomes