If you do this stuff for a while from basics and MDR, it gets to the stage where you can do complex plans, off the cuff Trails, live re-routed Trails (
), ETP, LPD, PNR, predicted available offload/time/range and achievable give etc.. pretty accurately while still flying your party tanker.
. However, if you have always pressed buttons for your answers, you are completely fcuked when the button falls off.
OAP