Dan,
To clarify a little further I have changed your scenario slightly.
In this case, the Met man has told the pilot that the wind is 090 at 60 and the pilot has planned based on that. It turns out that the wind is calm. Let's see what your pilot does;
The left example follows your use of the SCA.
Pilot Departs A. At B they discover that they are off track and apply the SCA. The think about it and decide that the Metman was wrong and there is no wind so the heading to fly the planned track is 000. So they do not change the SCA heading further. Unfortunately, after the SCA time is up they are no closer to planned track than they were at B!!
Following what I say (right diagram) - pilot determines that metman was wrong and there is no wind so they fly 360 becuase that is the heading they should have flown since A and it kills the drift. They then apply SCA for 4 minutes because they are 4nm off track and hey presto they are exactly back on track.
So SCA and then drift correction does not work in this case.
Can we not use a SCA procedure that will work and not just in certain cases?
Ask yourself why the right hand diagram is the exact same in both cases while the diagram of your system (the left one) changes?
BEagle is being very quiet. Will be stride in and put us both right?
