Wind Correction Angle & Ground Speed
The wind triangle solved exactly: wind correction angle, heading and ground speed from course, TAS and wind, plus leg time and fuel at your burn rate.
The heading that holds your course, the ground speed you will make, the headwind and crosswind components, and for a leg of a given distance its time and the fuel at the burn rate you enter.
Example: Course 090 at 110 kt TAS with wind 045 at 20: correct 7.4° left, heading 083, ground speed 94.9 kt; 120 nm takes 1 h 16 min and 10.7 gallons at 8.5 per hour.
The E6B wind side,
without the slide.
What the wind triangle is, how the correction angle and ground speed are found exactly, what the leg figures assume, and why the references must match.
The triangle
Three vectors close a triangle: the aircraft’s motion through the air (true airspeed on the heading), the air’s motion over the ground (the wind), and their sum, the track and ground speed. To hold a course the crosswind component of the wind must be cancelled by the aircraft’s own sideways component: TAS × sin(WCA) = W × sin δ, where δ is the wind angle relative to the course. So WCA = asin(W·sin δ ÷ TAS), the heading is course plus WCA (positive to the right), and the ground speed is TAS × cos(WCA) minus the headwind component W × cos δ.
Leg time and fuel
A leg distance divided by the ground speed is the time; multiplied by the burn rate you enter, the fuel. The burn rate is whatever your handbook or your own records give for the cruise setting — gallons, litres, pounds — and the fuel comes out in the same unit. Climb, descent and reserves are not in the leg figure.
Same reference for both
Course and wind must be measured the same way: a forecast wind is true, so use a true course (or convert the wind by the variation); a tower wind is magnetic and pairs with a magnetic course. Mixing them puts the variation straight into the correction angle.
What the number does not settle
One leg with a constant wind; wind that changes with altitude or along the route needs the leg split. The page does not know your climb or descent profile. A planning aid, not a substitute for the pilot’s operating handbook, the aircraft’s limitations or the rules that apply to the flight. Inputs stay in your browser; the same anonymous usage counts as the rest of the site apply.