Cheers guys, found a good and clear explanation in Oxford manual, so I get it now, thanks.
But can you clarify this?
In a glide, best angle is found when D/L is minimum....ie least drag for most lift which would be Vimd.
But for the best rate of descent again the notes say when D/L is minimum, but that min.D/L in this case is not Vimd but less than Vimd?
Also can anyone clarify what is going on in a descent with power for prop and jet ac?
......and does anyone fancy sitting my Perf. and PoF exams maybe???