DL - it rather sounds as if your 'cadet' is not familiar with the CDA principle as DF says - and you do not say where this 'operation' is taking place, but perhaps a quick reminder to 'lad/ladess' of the 3 x tables and suggest starting at 1000fpm if not 'pushed' for height while he/she does the maths and then arranging r of d to suit desired vertical profile once 'high/low' etc has been mentally (or magenta line if they must !!) computed?