Because of the task saturation accompanying low altitude flight, determining how to maintain
course navigation through the low level is an important part of mission planning. In military
flying, visual fixing is your primary means of low altitude navigation. Radar, GPS, and INS are
all great "crutches," but it all starts with visual situational awareness. The focus of this Chapter
is the techniques and procedures we used to determine the best features for intermediate
checkpoints and turnpoints.
CHARACTERISTICS OF GOOD CHECKPOINTS
One of the most important qualities of a checkpoint is that we be able to see it. There are several
factors determining the quality of a visual checkpoint. Size is important, as a larger feature can
generally be seen from greater distances and is easier to identify.
Horizontal development refers to the "width" of the feature. Coastlines, lakes, roads, and rivers
are examples of features with large horizontal development.
Vertical development refers to height, towers, mountains, and other man-made structures.
The ideal checkpoint has both vertical and horizontal development. Such a point might be a tall
bridge across a wide river or a large factory complex with tall smoke stacks (Figure 3-1,
point "B"). Unfortunately, such points are not always available.
For T-6A flights, horizontal development is more desirable than vertical development due to the
altitude flown (1000 feet AGL: Figure 3-1, river bends at 9+12 and 10+00).
In lower altitude flight (500 feet AGL), vertical development will prove more effective, as
horizontally developed features become masked by trees and a shortened horizon (Figure 3-1,
towers at 14+10).
When choosing features to serve as checkpoints, remember the goal is to fix your position as
accurately as possible. While the airfield is a good example of horizontal development, it may
not provide the most accurate position unless a distinctive structure or runway is used
(Figure 3-1, airfield at 11+20).
VISUAL FIXING 3-1