Summary - P-8690119

T-6A NAVIGATION

CHAPTER FIVE

Crosswind. 1 NM over 8 minutes is the equivalent of 1/2 NM over 4 minutes which equates to

6 knots of wind from the right (using the 6 minute rule). This can be rounded up or down (in this

case rounded up to 10 was used because it was on the low side of 6 minutes, i.e., only 4 minutes).

Head/Tail Wind. Over 8 minutes, 22 additional seconds late equates to approximately 3 seconds

per minute. Multiplied by 6/2 will yield 11 knots. This is also rounded to 10 knots of additional

wind. The wind is on the nose because we are late (i.e. a headwind).

Total wind. The original wind was 120/15, which gave us a left component of 10 knots. With

new components added, the crosswinds cancel out (10 left + 10 right = zero) and the headwind

increases to 180/15 (5 knots of headwind plus an additional 10 knots of headwind = 15 knots

total).

Compensate for the new wind. Since there is no crosswind heading should be 180 (which is the

magnetic course for this leg so no crab is required). Compensated airspeed should be 195 knots

(base of 180 knots + 15 knots for headwind). The aircraft probably still has a timing correction

still in, so aircraft airspeed should be 215 knots (195 knots + 20 knots).

Compound wind problems can be confusing, but if done correctly will keep the aircraft on

course. Winds are constantly shifting, but the tools provided here will aid in keeping the aircraft

on time and on course.

513. SUMMARY

This section includes all the actual mechanics of visual low-level flight. The next "step" is to put

it all together in the T-6A during the actual Navigation sorties! Using the fundamental method

explained in this chapter, you will be able to keep the aircraft on time and on course to the target.

For course corrections, if you are a known distance off course, use the standard course correction.

This consists of a 10, 20, or 30 degree change from heading held for intervals of one minute.

However, if at an unknown distance from course with a known point in sight (on or closer to

course), a BDHI correction is ideal.

To correct back to mission timing, remember a 20 knot change (10%) corrects 6 seconds for each

minute of correction and a 40 knot change (20%) corrects 12 seconds for each minute. Only 20

knot or 40 knot adjustments are permitted, and only when at least 12 seconds off in time.

The key to successful low-level navigation is planning. The best way to ensure success is to

understand the factors, which affect the aircraft, and to know the procedures cold. Turnpoint

procedures and standard corrections should be second nature before you walk into the brief.

Here are some hints for successful completion of low-levels:

Get the charts drawn as soon as possible! Time between your first Navigation flight and this

course is deceiving! Spend the night prior "chair-flying" the mission, not drawing the chart!

FLIGHT PROCEDURES

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