Figure 2-5 Time Ticks

CHAPTER TWO

T-6A NAVIGATION

For the first leg, measure and mark time ticks beginning at the entry point and proceeding to the

second point (A to B). Do not draw time ticks within the turnpoint circle. As a result, some time

ticks may not appear (Figure 2-5). For all other legs, measure distances backward along the

planned track. This is done to minimize errors due to rounding of distances.

Rules for drawing Time Ticks:

No time ticks should be drawn in the turnpoint circle.

Only the third minute tick marks (3, 6, 9, 12, etc.) are labeled.

Labeling is as shown in Figures 2-5 and 2-6. Ticks are labeled with only the whole minute. A

tick labeled as "3+00" would indicate there is an intermediate checkpoint at that time tick.

For F5101 and F5102, base time ticks on 240 knots, or 4.0 NM/minute.

Figure 2-5 Time Ticks

In Figure 2-6, if the total enroute time to point "D" is 13+20, then measure back from point "D"

20 seconds worth of distance (1 NM). This would be the location of the 13 minute time tick.

However, since this time tick is within the turnpoint circle, the next time tick drawn is the 12

minute tick, drawn 3.0 NM prior to where the 13 minute mark would have been drawn

(Figure 2-6).

1. Measure back from "D" 20 seconds worth of distance (1 NM). Mark this point with a pencil.

2. The pencil mark is the 13 minute mark, but it falls within the turnpoint circle and is not

annotated. Now measure back towards "C" another minute worth of distance (3 NM). This is

2-6

LOW-LEVEL CHART PREPARATION