Originally Posted by
HIGHFLY33
When relating the "climb gradient" to ground distance the correct term to be used is Flight Path Angle
As
HazelNuts39 and
Intruder have said, a gradient is a ratio, usually expressed in percent. Therefore, it would be wrong to call a climb gradient which is based on ground distance a flight path angle. The fact you can calculate a flight path angle from still air climb gradient and wind data is another story, but still a gradient is a gradient and an angle is an angle.
Originally Posted by
HIGHFLY33
Clearly the wind effective gradient is different and it is this that gives the flight path angle.
Yes, it 'gives' the flight path angle, i.e. the flight path angle can be calculated from the wind effective gradient.
As far as you ask for references, I could offer the following two definitions, but I'm afraid they contradict your assumption 'flight path angle' was a better term for a ground based climb gradient.
For every point of the aircraft’s flight path, the angle of climb γ is the angle between the airspeed vector and the horizontal plane (Torenbeek/Wittenberg, Flight Physics, Springer 2009, p 279)
The climb gradient is the ratio between the height increment dh and the horizontal distance travelled ds during a small time interval dh (loc. cit., p 280)