Hi Paul,
I agree that the flight computer can be a bit of a nightmare. I was taught to use the wind down method, but always got confused-I found that the wind up was easier for me(I use the CRaP-5, not that it makes any real difference)! Try this:
Find magnetic heading and groundspeed given the following conditions:
Magnetic course 095°
True airspeed 98 kt.
Magnetic wind 150° at 20 kt.
Rotate the plotting transparency so the magnetic wind direction of 150° is opposite the True Index.
Move the sliding card so the grommet is over a convenient speed arc, such as 100.
Using the speed arcs, place a dot 20 kt. up from the grommet. This represents the wind speed, also called a wind dot. If the grommet is on the 100-kt. speed arc, the dot should be placed on the centerline at the 120-kt. speed arc.
Rotate the plotting transparency so the magnetic course of 095° is opposite the True Index.
Move the sliding card so the wind dot is on the 98-kt. speed arc, which is the TAS.
The WCA is determined by the wind dot and the wind correction lines. In this example, the wind dot is 10° to the right of the center.
+R
Magnetic heading (MH) = MC WCA.
-L
In this problem, MH = 105° (95 + 10).
Groundspeed is read under the grommet; it is 85 kt. in this example.
Under the given conditions, the magnetic heading is 105° and the groundspeed is 85 kt.
Hope this helps!