Figure 5-15 T-6A Airspeed/Temperature Chart

CHAPTER FIVE

T-6A NAVIGATION

511.

COMPENSATING FOR WIND

For T-6A Navigation this is done prior to takeoff by winding the chart first as discussed at the

beginning of the chapter. In order to accomplish this in flight, you must have already come up

with a total wind direction & magnitude.

Calculate crab just as you did in instrument navigation. At 180 knots, crab 2 for each 5 knots of

crosswind. Round wind values to the nearest 5 knots so your adjustments to base-heading are

always in 2 increments. The value of 2 for every 5 knots comes from the following formula.

Crosswind

Drift

NM/min (TAS)

~2 crab

5 knots

3.0 NM/min

You will also have to adjust for the head/tailwind. Make adjustments to your base airspeed (the

indicated airspeed you calculated to fly 180 KTAS (Figure 5 -20) in 5 knot increments for the

head/tailwind you encounter.

Example

Aircraft is on a base heading of 072, base airspeed is 175 KIAS for 180 KTAS. At time 4+30

the aircraft passes 1/2 NM right of a checkpoint which you preflighted/updated to be on course at

time 4+05. Estimate the wind and the appropriate compensations.

Using the 6 minute rule: 1/2 NM X 10

= 5 knots left crosswind

25 sec late

= 12 knots headwind

Total wind = 12 knots + (1/2 X 5 knots) = 15 knots total wind

T-6A AIRSPEED/TEMPERATURE CHART (180 KTAS)

TEMPERATURE RANGE

IAS

+49C and higher

170 IAS

+11C to +48C

175 IAS

-9C to +10C

180 IAS

-29C to -10C

185 IAS

Figure 5-15 T-6A Airspeed/Temperature Chart

5-30

FLIGHT PROCEDURES