The wind side of an E6B

Published by PilotDeskSources, testing & corrections

Use the online E6B flight computer when you want the numerical answer, or use this page to understand the wind-side geometry. The wind side of a traditional E6B flight computer is a graphical way to solve the wind triangle. It connects true course, true airspeed, wind direction and wind speed to the corrected heading and groundspeed needed for a planned leg.

The problem it solves

Wind moves the entire air mass. An aircraft pointed directly along the desired course can drift sideways, and a headwind or tailwind can change the speed over the ground. The wind side combines those effects in one vector diagram.

Wind correction angle

The difference between desired course and corrected heading is the wind correction angle. The correction is made into the wind so the resulting ground track remains on the planned course.

Groundspeed

The same construction produces groundspeed. That value belongs in ETA, leg-time and fuel calculations because it describes progress over the ground rather than speed through the air.

Plot the wind and true airspeed

A training sequence is to plot wind direction and wind speed, set true course, use true airspeed, then read wind correction and groundspeed. The exact mechanical steps depend on the E6B model and instruction method, but the underlying vector relationship is always the same.

Why drawing the triangle helps

A graphical wind solution makes it easier to see why a crosswind changes heading and why headwind or tailwind components change groundspeed. It also provides a useful reasonableness check for an electronic answer.

True versus magnetic

The wind triangle is commonly solved using true directions. Magnetic variation can then be applied when the final heading needs to be magnetic. Keeping those stages separate helps prevent sign and reference errors.

Electronic E6B tools

Electronic calculators solve the same math numerically. They are faster, but understanding the wind side still helps pilots recognize an impossible answer, a reversed wind direction or an incorrect course entry.

Related PilotDesk guides

Wind correction angle · Course, heading and track · Groundspeed vs airspeed

Eastbound course with wind from the south

Use course 090° true, 100 kt TAS and wind from 180° true at 20 kt. The wind moves the airplane north, so the heading must point south of east. Resolving the vectors gives about 101.5° true heading and 98 kt groundspeed. A heading north of 090° would reinforce the drift instead of correcting it.

On a conventional wind-side E6B, set wind direction under the true index, mark the wind speed above the grommet, then rotate to true course and slide the wind dot to the TAS arc. Read groundspeed at the grommet and wind correction from the dot’s displacement, using your model’s scale instructions. Compare with the wind-triangle calculator. Keep true references throughout; apply charted magnetic variation afterward.

See the wind-triangle diagrams and flight-computer discussion in the FAA Pilot’s Handbook of Aeronautical Knowledge, Chapter 16.