Figure 4-5 Turn to Course

CHAPTER FOUR

T-6A INSTRUMENT NAVIGATION

408. DOUBLE-THE-ANGLE INTERCEPTS

The DTA intercept is a maneuver that provides a shallow and easily controlled rate of intercept

to a desired course. The spacing between radials decrease the closer you get to the station. A

large intercept angle, when close, could very easily result in overshooting the desired course. A

DTA intercept would prevent this.

PROCEDURE

During the last half of the turn toward a desired course, note the number of degrees

between the head of the bearing pointer and the desired course inbound.

Plan the rollout to stop on a heading double the number of degrees from the desired course

to the head of the bearing pointer. In other words, place the head of the bearing pointer halfway

between the aircraft heading and the desired course.

The head of the bearing pointer is now in a position to fall to the desired course. Figure 4-5

illustrates a DTA intercept to a course of 260.

A/C Heading 260

265

260

A/C on 085 R

Figure 4-5 Turn to Course

As the head of the bearing pointer falls, maintain heading until approaching the desired

course. Monitor the bearing pointer and CDI and initiate a turn to course. Once established on

course, apply drift correction and resume tracking procedures until station passage. Since the

aircraft is close to the station, only small changes in heading will be necessary to maintain

course.

COMMON ERRORS

Overshooting the desired course.

Not applying drift correction once established on desired course.

Chasing the bearing pointers close to the station.

4-16 INSTRUMENT NAVIGATION