On the outer (DISTANCE) scale, find the distance of 350 nautical miles (the 35).
Now read directly below 35 (350 NM). The time en route will be 140 minutes or 2
hours and 20 minutes (2 + 20). (Figure 4.3-17)
Figure 4.3-17 Time 2
2 hours and 20 minutes
At times, it may be necessary to work small, or short, distances and times (low level/high
speed navigation). The answer will be a short period of time, in minutes or minutes and
seconds. The smaller index marked "SEC" (located at figure "36" on the inner, or TIME,
scale) is referred to as the "seconds bug" or "high speed index." The "high speed index"
converts a 60-minute (one-hour) time period into 3600 seconds. When the "high speed
index" is placed beneath the speed on the DISTANCE scale, any distance read on the
DISTANCE scale will correspond to time in seconds on the TIME scale.
Ground speed . . . . . . 250 KTS
Distance to travel . . . . . . 5 NM
Time to fly