distance between two points on the earth
I remember from my atpl training that to find the distance between two different longitudes on the same latitude we used the formulae for departure
ie 15w to 25w on the 60 deg lat = 600 x .5 = 300nm
but what if the 15w was on the 30 deg lat and the 25w was on the 60 deg lat.
how do you work out the distance??
do you take the mean lat ie 45
so 600 x cos 45(.707) = 424nm
Many thanks in advance