Figure 6-7

STUDENT GUIDE

VISUAL NAVIGATION

Figure 6-7

6.5.4.7. After the course line is in place, erase the excess turn radius markings so the final result

is a smooth turn depiction. Whether a dime or template plotter is used, the result should be the

same as illustrated in figure 6-7.

6.5.5. Measuring Course

6.5.5.1. Measure the true course for each leg along the plotted course line using the same

technique as used for T-34 VNAV charts. Apply magnetic variation to obtain the magnetic

course, remembering that east variation is subtracted from true course, and west variation is

added. Record these courses in the data table as was done for T-34 VNAV charts.

6.5.6. Selecting the Appropriate Altitude

6.5.6.1. T-1A/T-39 visual navigation within established low-level routes is based on flying AGL

altitudes rather than MSL altitudes. Typically, the low-level routes are flown at 500 feet AGL or

the lowest AP-1B allowed altitude, whichever is higher. The 500-foot minimum restriction

comes from OPNAVINST 3710.7 Sect. IV and AETC instructions, but a higher prescribed

altitude in AP-1B takes precedence. For example, if AP-1B dictates the route altitude structure

from point A to point B is 300 to 1500 feet AGL, then that leg is flown at 500 feet AGL. If,

according to AP-1B, the minimum route altitude is 700 feet AGL, then the route is flown at 700

feet AGL.

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