Flying The Route
FLYING THE ROUTE
READING THE CHART
Knowing your chart is of obvious importance. Study the chart, and use your imagination about what
to expect. Experience is helpful in this matter. As you progress through the ONav syllabus,
following landmarks will become easier. Notice the symbols for roads, railroad, and rivers. Check
where the roads go; a road between large towns is likely to be heavily traveled and wider than one
connecting small country towns. Is the road labeled as a U.S. highway or a state highway? The U.S.
highway may not be any wider, but you can expect to see more traffic on it. At crossroads, try to
project what may be there beside the roads. What vertical definition might you see? Railroads have
more stringent requirements for construction than highways and you see them easily. Even an
abandoned roadbed may be easy to see and use as a landmark. Rivers and streams may not be
very good, especially during floods, droughts and at times of year when leaves are off the trees. If
you can tell which way rivers are flowing, you may be able to funnel to a larger stream or a recog-
nizable bridge. Forget trying to count the streams you cross; all are not always shown on the charts.
All checkpoints and landmarks should be studied not as singular points, but in terms of overall
environment associated with the "checkpoint." Consider the checkpoints in the categories identified
below. Refer to Figures 1 and 2 for examples of these various types of landmarks.
Positive landmarks can be positively identified and plotted as a point on a chart. Mountains and
large natural bodies of water are very good positive landmarks. You need not pass directly over a
positive landmark for it to be useful to you. Be cautious when using man-made landmarks, as they
may have changed, moved, or no longer exist.
Linear landmarks are features which can be positively identified but not specifically plotted because
they extend for some distance. Features such as roads, railroads, coastlines, power lines, and rivers
may make good timing checkpoints if they are perpendicular to the course line and have other
specific environmental particulars that identify your position. A power line should be large and not
easily confused with other lines near. Rivers must be identified positively. It helps if they are either
isolated or very large, and you should have some confirming landmark to ensure that you have the