Figure 4-17 Correction Orbit

CHAPTER FOUR

T-6A INSTRUMENT NAVIGATION

Heading

075

Heading

278

090

Figure 4-17 Correction Orbit

NOTE

As has already been mentioned, wind is thought of as being from a

cardinal heading in holding. Figure 4-17 shows the wind must

actually be from the north east, since the inbound leg was 60

seconds. However, for ease in determining heading corrections, it

is best to think of winds as being from cardinal headings.

If the corrections determined in the no-wind orbit do not put you on course for 1 minute on the

first correction orbit inbound leg, you must re-correct the next outbound leg. The amount,

direction, and time to correct are determined exactly as in the no-wind orbit, but the corrections

must be applied to the heading and timing used on the previous outbound leg, not the first

outbound leg. It may take several orbits to get the heading and timing exactly right.

Confirm EFC time with Approach Control at least 5 minutes prior to the EFC. Receipt of EFC is

not a clearance to commence approach at that time unless you have lost communications with

ATC.

HOLDING DURING ADVERSE WIND CONDITIONS

It is not unusual for winds aloft to attain velocities well in excess of 20 KIAS. In these

circumstances, some modifications to the holding procedures discussed earlier may be necessary.

Just how much you modify normal holding procedures will, of course, depend on wind speed

and direction. If you feel you need to use modified procedures, be sure to discuss this with your

instructor.

You should be able to predict high winds prior to entering the holding pattern. Pay attention to

the forecast winds aloft. During the enroute phase, a high crosswind component would be

4-40 INSTRUMENT NAVIGATION