geraldflyagain,
I suspect that your difficulty stems from the fact that ATPL studies concentrate only on the effects of northerly and southerly movement. But movement in any direction over the surface of the Earth will cause coriolis effect.
If you do a google search of Eotvos Effect you will find a link to a wikipedia article. The maths may prove to be a bit off-putting, but the diagrams and explanations (particularly in the section of motion along the 60 degree latitude) will probably be more helpful.
Last edited by keith williams; 31st May 2016 at 22:17.