calculating max drift
learnt this one off my cfi and it works a treat
windspeed divided by tas in miles per minute
tas 120 knots i.e 2 miles per minute wind 360/20
20/2 = 10degrees max drift
now this is a bit confusing but great if i can explain it well enough without a picture
you takeoff off on a flight with a pre calculated max drift of 10 degrees in the above example
you turn onto a track of 330 for example on the dg. look to where the wind is coming from and drop the line straight up or down as applicable. if it falls half way along the horizontal from the centre of the dg you have half of 10 as your drift, if it falls 2/3 the way along you have 2/3 of the 10 as your drift etc. try it, i guarantee it will be accurate to within 1 degree of what you get off your whizz wheel. cheers glen