If you mentally estimated a heading of 060° for 56 NM, you are well on your way to a good
understanding of point-to-point navigation. The diagram should help those who have trouble
with the mental picture. To interpret the diagram, you must estimate the direction of the dotted
line. You have references to work with, however. Notice that the dotted line is canted somewhat
(about 30°) north of the 090° radial. If that is the case, then the line must represent a course of
060°. As for distance, notice the length of the segment connecting the TACAN with 090/50. It
is obviously 50 NM. If that line is 50 NM, then the dotted line is certainly longer (about 5 NM
longer) than 50 NM. These rough estimations will help prevent your making erroneous
decisions concerning your point-to-point navigation, and they will help you build confidence in
your navigation abilities.
So that the principles of point-to-point navigation might be more clearly understood, it is
convenient for us to use the CR-2 navigation computer; specifically, the wind side. When using
the CR-2, the center or grommet on the wind side is equated to the location of the TACAN
station, common to both your present location and the point to which you wish to proceed.
To plot your position on the computer, utilize the methods you have learned for plotting
winds, i.e., substituting TACAN radials for wind directions and TACAN DME for wind velocity.
It is very important that you distinguish between your position and the point to which you are
proceeding. One method is to use a triangle (or target) as your desired destination and a circle as
your own position.
Figure 2 illustrates an aircraft presently on the 360°R/40 DME. Your desired position is in
the 270 R/30 DME. Note the plotting of the two positions.
TACAN POINT-TO-POINT 5-3