A final consideration is the information an intermediate checkpoint provides. Roads or rivers
running parallel to your planned track give information regarding course, while roads and rivers
running perpendicular to your track give information regarding time. Ideally, an intermediate
checkpoint should give both types of information, such as a tower or a bridge indicating the
course and time deviations.
CHOOSING AND ANNOTATING INTERMEDIATE CHECKPOINTS
After selecting intermediate checkpoints, annotate them on your chart by simply placing the time
in minutes and seconds next to the point, but outside of the tick marks. Figure 3-1 shows
checkpoints properly annotated. Indicate intermediate checkpoints in black ink with only the
time annotation. Typically, you can expect to have approximately six to eight intermediate
checkpoints annotated on a T-6A Navigation chart.
But what if you want more? In flight, it is important to use planned as well as unplanned
intermediate checkpoints. Using the concept of CLOCK, CHART, GROUND, use any feature
along your flight path to fix your position in flight (process discussed later in this chapter).
Intermediate checkpoint selection is important, as errors in selection/plotting of intermediate
checkpoints may lead to becoming excessively off course.
DERIVING INFORMATION FROM VISUAL FIX POINTS
Intermediate turnpoints on a low-level chart can only help us if we know how to find and use
them. By keeping the chart oriented with the track of the aircraft, landmarks on the ground
appear in the same relative position as the features on the chart.
But what will the feature look like? Geography, climate, altitude, and season are just some of the
factors affecting the appearance of checkpoints. As your flight experience increases, so will your
ability to predict how a particular feature will appear from the air. Below are some points to
consider when searching for specific features:
Trees may mask roads running perpendicular to course. Look for traffic, particularly
Rivers may be masked just as roads are. Look for changes in forest color. Typically,
deciduous (leafy) trees will grow next to the rivers, while pines will grow everywhere else. Also
look for the lower terrain associated with the riverbed.
Pay close attention to the contour lines on your chart. They may indicate terrain trends
useful for navigation or terrain that may hide other checkpoints.
Observation towers (generally placed in forested areas) may only appear as a small building
sitting on the tree line.
3-4 VISUAL FIXING