Locate the "RATE INDEX" (▲) on the inner scale. (Figure 4.3-21)
Figure 4.3-21 Speed 2
Above the "RATE INDEX" read the ground speed. Because of the estimation of 180,
the correct answer can easily be determined.
164 KTS ground speed.
Solutions to problems requiring a distance flown, or a distance to be flown, over a known
period of time may be solved in a manner similar to solving problems of time. Again, it is a
process of setting up a ratio using the DISTANCE and TIME scales and the basic SPEED,
DISTANCE, TIME equation.
Given: Ground speed . . . . . . 240 KTS
Time flown . . . . . . . . 19 minutes
Find: Distance flown
Estimate the answer. 60 goes into 240 4 times. 19 times 4 is approximately 80.
Set the RATE INDEX (▲) on the inner (TIME) scale opposite the ground speed (240
KTS) on the outer (DISTANCE) scale. (Figure 4.3-22)