Originally posted by dick Hanson
thanks again - I think I have the concept in grasp now
which is: basically - if there were no fixed losses in the powerplant - the load and the developed power would rise and fall -pretty much the same -- the constant losses in the engine are the "gotcha ".
Close enough for folk music?
Yup, as far as RPMs are concerned.
The following is just further clarification:
But the fact remains that the power that that RPM is putting out has been decreased, resulting in weaker climbs, etc. Also, the plane has to fly faster to achieve the same CL, say the best lift to drag condition.
The faster speed can be taken care of by increasing pitch, which is why that's often recommended. There's no drag cost for this, since drag is decreased just as lift was. But there's nothing than can be done about the available power without changing the displacement of the engine or adding some sort of intake compression (turbocharging, turbocompounding, or supercharging).
Just wanted to make clear that the same RPM at different densities is not the same amount of power.