Figure 19 - P-8010114

INSTRUMENT NAVIGATION

Figure 19

Note the solid arrows (Figure 19) which portray a headwind and a left crosswind. The sum

of those arrows is represented by the dotted arrow in the Northwest quadrant.

In a no-wind situation, your track should be directly along the line that connects the two

points, a course of 350. If you were to take up a heading of 350, however, and you still had that

northwesterly wind, you would soon find yourself off course, and behind schedule.

In order to maintain a track of 350', you must crab into the wind; and in order to determine

your time of arrival at the desired point, you must be aware of your ground speed.

Ground speed calculations during point-to-point navigation are more difficult than in radial

tracking because we can not directly utilize our changing DME. In order to compute a ground

speed, we must somehow measure our actual forward movement relative to a constant source.

For our purposes, we will use the CR-2 and the pencil.

To get a ground speed from the CR-2, simply note the distance you move from one TACAN fix

to another over a set period of time (Figure 20).

5-16 TACAN POINT-TO-POINT