What is the wind correction angle?

The wind correction angle, or crab angle, is how many degrees you point the nose into the wind so the aircraft tracks your intended course over the ground. It is found from the arcsine of the crosswind component divided by true airspeed.

How is groundspeed calculated?

Groundspeed equals true airspeed times the cosine of the wind correction angle, minus the headwind component. A headwind and a large crab both reduce groundspeed, while a tailwind increases it. The tool combines these from the full wind triangle.

Is wind direction the way it blows from or to?

Aviation wind is always reported as the direction it blows from, in degrees true for forecasts and winds aloft. Enter that from direction. A 270 wind is a westerly, blowing from the west toward the east.

Why is the result a true heading?

The wind triangle works in true degrees because winds aloft and courses are charted in true. To fly the compass, apply local magnetic variation, easterly subtracted and westerly added, and then deviation, to convert the true heading to a magnetic heading.

What if the crosswind exceeds true airspeed?

Then the wind triangle has no solution and the tool says so. Physically the aircraft cannot make good that course because the crosswind is faster than the aircraft can fly. You would need a different course or to wait for the wind to ease.

Wind Correction Angle Calculator

Every cross-country leg flown in wind needs a heading that is not the same as the course line on the chart. This calculator solves the classic E6B wind triangle to find the wind correction angle, the heading to fly, and the groundspeed you will actually achieve.

How it works

The wind triangle relates four vectors: your desired track, the aircraft through the air, and the wind. The tool computes the wind angle relative to the course, splits the wind into a crosswind and a head or tailwind component, then finds the correction angle:

wind angle = wind direction - true course
crosswind  = wind speed x sin(wind angle)
headwind   = wind speed x cos(wind angle)
WCA        = arcsin(crosswind / TAS)
heading    = true course + WCA
groundspeed = TAS x cos(WCA) - headwind

A positive WCA means crab to the right into a wind from the right.

Worked example

On a true course of 090 at 120 kt TAS with the wind from 150 at 20 kt, the wind is partly a crosswind from the right and partly a headwind. The tool returns a small right crab and a groundspeed below 120 kt — exactly what you would read off a mechanical E6B.

Notes

The output is a true heading. Apply magnetic variation to get a magnetic heading for the compass and directional gyro. Use this tool to build flight logs and to sanity-check the answers from a flight computer or EFB.