I’m in the process of designing a flight planning spreadsheet so that I don’t have to keep doing all the repetitive calculations by hand. One of the calculations involves working out the heading required to maintain the desired track in windy conditions, or in other words, how much you have to turn the aircraft to compensate for the drift caused by the wind. This is usually done using a “flight computer” such as the E-6B, known colloquially as a “whiz wheel”.
But what exactly does the wind side of the whiz-wheel do? How does it work? Before I could add the calculation of the wind-correction-angle and subsequent ground speed to my spreadsheet I first had to derive the solution to the Triangle of Velocities. I thought a page showing the solution here might be useful to the next person trying to solve the problem.