The problem is that the RAF is trying to apply a system which works for still/air low level high speed navigation, where W/V is of little consequence, to medium level navigation at low speed in the Plastic Pig, where W/V is highly significant.....
The same logic which uses MDR for pre-flight planning purposes, resulting in inaccurate GS values. It is actually OK to plan a low level navigation trip at 240 KIAS+ using still air, but to use MDR for
pre-flight planning at 120KIAS is inadequate for GS calculations.
This is the 'running before you've learned to walk' approach, using elementary training aeroplanes for purposes for which they are quite unsuitable. Why? Because they can't afford to operate proper basic trainers such as the Jet Provost these days....
