Difference between prop endurance and jet endurance

[Dennis Straussfogel <dms@xxxxxxxxxxxx>]

> In "aerodynamics for naval aviators" there is a part about drag curves, 
> min. power and min. thrust required.
> 
> At minimum drag, minimum thrust is required. This one I understand.
> And that at this point endurance is greatest, I understand too.
> 
> What I don't understand is:
> Whats the difference to minimum POWER required?
> This point is not at minimum drag but at about 75% of this speed where
> total drag is bigger.
> 
> Why is this so? I don't understand.
> I thought minimum power required should also be at minimum drag.
> 
> Has anybody an easy answer?

Power required is given by the product of drag and true airspeed, so the 
minimum power required is the point where D*V is a minimum. 

Dennis Straussfogel, Ph.D. 
Aerospace Engineering Consultant