From here:
What is the Coriolis effect?
'As discussed earlier the effect of Coriolis effect on a hypothetical plane, the word hypothetical was used just to signify that the frame of reference for watching the plane was several kilometers away from the atmosphere of earth.
If this frame of reference is taken on earth itself i.e. we are observing a plane flying over our head standing on the surface of earth then Coriolis effect won't play any role as we are also moving with the atmosphere of earth. So it is all about the frame of reference which we are talking about.
Coriolis effect would play an important role in case of Rocket Propulsion as rockets leave the atmosphere of earth.
Though
the Coriolis effect does not affect the airplanes directly it has an indirect effect on the flight path by producing various phenomenon related to wind motion such as vortex winds, Jet streams etc.'
You are ignoring the frame of reference. The maths is useless unless you take that into consideration. The only adjustment any plane makes is, as it says, due to atmospheric conditions. It plainly says (and you will completely ignore this) that the
Coriolis effect won't play any role.
I might have a browse later to see what other nonsense is on that website. In the meantime, do you have a copy of the map that was requested earlier? You know, one to scale that shows the correct sizes of continents?