Choosing and Annotating Intermediate Checkpoints

CHAPTER THREE

T-6A NAVIGATION

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.

303.

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.

304.

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

trucks.

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