OK, thanks. I profess to not know much about "power" and props. But what I do know is that at any level, in a jet, the fuel flow for the same indicated speed will be basically the same, notwithstanding minor variations caused by compressibility and other slight changes in the various drag types. That is, the thrust ie the stuff going out the back to counter the drag, will be the same. I leave the explanation of why to the rocket scientists.
So I do not agree that it will take more fuel to fly (a jet) at 150IAS at 10,000ft than 5000ft. The "power" required might be double (or 3.375 times at FL300) but the thrust/FF certainly isn't.
I simply cannot understand why the drag at FL300/250KIAS/440TAS is allegedly over three times that at 250KIAS at sea level. Drag is all about the aerofoil and the body pushing through the local airflow. At 250KIAS, that force much must be the same. The nil-wind speed over the ground ie the TAS, in my view, has no bearing on anything to do with drag.
Going to extremes, how about the ISS in low earth orbit? Massive TAS, but no IAS, no lift and no drag. No thrust required to keep it up there (apart from a few squirts occasionally to resist G ravity). Is there any power required? Apparently yes...
