The next four steps (Turnpoint, Time, Update and Wind) provide us a position analysis process
that analyzes where the aircraft is now, after the geometry effects of the turn. These four steps
will get the aircraft back on mission course and timing.
This is the first step of four which will get the aircraft back on the mission course/time. We must
understand how a turn affects our course. During turnpoint analysis, you determine the plane's
actual position in relation to the black line and tick marks on your chart, then you attempt to
correct the aircraft back onto course.
Turnpoint Geometry. If you are not directly over the top of a turnpoint, you will actually
increase/decrease the distance the aircraft has to fly to stay on mission profile. After a turn, you
must analyze the consequences of the turn geometry as it relates to course centerline.
Determining how far off course you are can be done by means of the relationships shown in
Figure 5-4. If you were off course by a known amount going into a turnpoint, afterwards that
distance will change depending on the amount of the turn. Knowing these relationships will help
determine distance off course and help establish time corrections.
Figure 5-4 Affect of Turn