Wind triangle

In air navigation, the wind triangle is a graphical representation of the relationship between aircraft motion and wind. It is used extensively in dead reckoning navigation.

The wind triangle is a vector diagram, with three vectors.

The wind triangle describes the relationships among the quantities used in air navigation. When two of the three vectors, or four of the six components, are known, the remaining quantities can be derived. The three principal types of problems to solve are:

The traditional method of solving wind triangle equations is graphical. The known vectors are drawn to scale and in the proper direction on an aeronautical chart, using protractor and dividers. The unknown quantities are read from the chart using the same tools. Alternatively, the E6B flight computer (a circular slide rule with a translucent "wind face" on which to plot the vectors) can be used to graphically solve the wind triangle equations.

On aircraft equipped with advanced navigation equipment, the wind triangle is often solved within the flight management system, (FMS) using inputs from the air data computer (ADC), inertial navigation system (INS), global positioning system (GPS), and other instruments, (VOR), (DME), (ADF). The pilot simply reads the solution provided to him.

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