The exact solution for length of tangent (assuming station at GL) is:
sqrt(2rh+h^2)
I admit it, I am mathematically challenged, but I don't get that. If I'm at 4000' then my range is 4000nm plus a shed load more? Which units?
I'm sure for the ATPLs it was something like height of Tx + height of Rx (feet), square rooted, x 1.25. Anyone more current?
It would have to be 1.25 * sqrt(H of Tx) + 1.25 * sqrt(H of Rx).
Bookworm,
The ATPL assumes line of sight.