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 2º for each 5 knots of
crosswind. Round wind values to the nearest 5 knots so your adjustments to base-heading are
always in 2º increments. The value of 2° for every 5 knots comes from the following formula.
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.
Aircraft is on a base heading of 072º, 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)
+49ºC and higher
+11°C to +48ºC
-9ºC to +10ºC
-29ºC to -10ºC
Figure 5-15 T-6A Airspeed/Temperature Chart