The groundspeed is the aircraft’s airspeed corrected to account for the wind direction and speed on the desired course.
The function calculates the heading required to fly a desired course, given the wind direction and speed.
The wind correction angle tells the pilot by how many degrees he should adjust his heading to the left (-) or to the right (+).
Wind Direction: 270°
Wind Speed: 10 Kts
True Airspeed: 90 Kts
Groundspeed: 89.4 Kts
Wind Correction Angle: -6 (6° to the left)