Appreciate the answers you are giving but they were given at least mathematically as part of my question: The latitude effect and the moving with the spin or against the spin of the earth.
Yes, the plane given these effects only would appear lighter going eastward but the question is, after these effects are subtracted would the plane be lighter going westward? Has this ever been calculated?
Are computers on some planes measuring wind velocity and the tendency of the plane to go in a wider(eastward) or lesser(westward) elliptical orbit instead of the circular orbit parallel to the surface of the earth etc..?