Figure 5-5 Effect of Turn

T-6A NAVIGATION

CHAPTER FIVE

When the aircraft marks abeam on the outside of a turn, another means of determining turnpoint

geometry corrections is by doing a "double mark-on-top." In this technique, the aircraft is

marked abeam the point initially to begin the turn. As the aircraft completes the turn, visually

acquire a second abeam point. Here you must note distance off course as well as the time. The

data at this second point will have the effect of turnpoint geometry already included in it.

Corrections for course. Standard corrections, BDHI corrections, and jungle rules are the

approved methods for course corrections during the intermediate phase of Navigation training.

The table in Figure 5-6 summarizes the standard course corrections for T-6A Navigation flights.

These simplified corrections are approximate and only apply for an aircraft at 180 knots. Notice

corrections larger than 30 are not allowed because of the effect it would have on course timing.

In addition, the turns to and from the desired track would induce additional course error.

EFFECT OF TURN ON TIME AND COURSE

DISTANCE ABEAM

TIME OFF

DISTANCE ABEAM

BEFORE TURN

DEGREES OF TURN

(SEC)

AFTER TURN

1 NM

30o

1 NM

3/4 NM

45o

1 NM

2/3 NM

60o

1 NM

1/2 NM

90o

1 NM

0 NM

120o

1 NM

1/2 NM (OPP SIDE)

135o

1 NM

2/3 NM (OPP SIDE)

180o

1 NM

3/4 NM (OPP SIDE)

180o

1 NM

1 NM (OPP SIDE)

Figure 5-5 Effect of Turn

FLIGHT PROCEDURES

5-13