Quite right TC, and to be even more pedanticer, couldn't we say that everything we see is historic
I think you'd agree though that it would be better to have a slightly historic indication of the surface that we have just flown over, calculated and indicated for us by the rad alt, than having to remember the topography and every contour line of that area; and then have to work out an historic elevation of that surface based on the QNH, that may have changed up or down while on the task ... at the same time handling a double engine failure ... at night
