Figure 4-16 Correction Orbit

T-6A INSTRUMENT NAVIGATION

CHAPTER FOUR

Figure 4-16 illustrates a typical no-wind orbit. In this example, the inbound turn resulted in an

overshoot and a DTA intercept was set. The TAIL-RADIAL-WIND rule indicated a wind from

the north. This resulted in a 15 heading correction factor and the inbound timing of 50 seconds

indicated a 10-second timing correction factor.

The third and subsequent orbits in holding are called correction orbits. Correction orbits are

flown by applying the correction factors determined on your no-wind and subsequent correction

orbits.

360

090R

50 sec.

Figure 4-16 Correction Orbit

We will apply our heading correction to the outbound leg. The wind is from the north and the

correction factor is 15. For the intercept to the inbound course, your heading would be 300

(i.e., DTA intercept). This will get you on the holding course inbound to the fix. A 5 crab is

then required to maintain course. The no-wind outbound heading would be 090. By applying a

triple drift of 15 to the outbound heading, our compensated heading is 075. Therefore, use

075 as an outbound heading on the correction orbit.

The inbound leg in Figure 4-17 took 50 seconds, indicating a tailwind component with a 10

second correction factor. To make the inbound leg a full 60 seconds, longer outbound timing is

needed. Apply the 10-second factor to 60 seconds (original outbound timing). The outbound

timing on the correction orbit is then 70 seconds. If the inbound leg of the no-wind orbit was

longer than 60 seconds, use the timing correction factor to shorten the next outbound leg (to a

minimum of 30 seconds on your first outbound leg see "HOLDING DURING ADVERSE

WIND CONDITIONS" on the next page).

INSTRUMENT NAVIGATION

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