pineridge,
Vibes,
Here's my earlier scribble (call it a vector diagram if you like) I did for the thread I mentioned earlier.
This one is strictly for the force balance in a steady-state climb, drawn for the horizontal and the vertical balance.
Re the sin(ac) and cos(ac) ... the "ac" is "angle of climb", happened to be the term used in the other thread for the flight path angle or climb angle.
Turns is another story.
Wizofoz, I've seen so many badly worded explanations I won't start on that one yet...
CJ