Perhaps I wasn't being clear by calling it a "max performance takeoff," but I was just referring to a vertical takeoff from a hover.
I thought I could get a rough estimate of power req'd to hover at a certain weight vs. maximum power available (at the transmission torque limit) assuming sea level, and this would give me an indication of power margin.
Maybe I should restate the question... what's a simplistic way to make a baseline comparison of aircraft performance, knowing little more than a manufacturer's spec sheet numbers, and perhaps some limits in the flight manual?
I ask this way, because knowing the aircraft's max gross weight, hover ceiling, and engine SHP, etc. as shown on a spec sheet, does not give me any immediate indication of whether or not it will perform better or worse in a specific mission profile, when compared with another aircraft listing similar specs.
RugGun, your explanation was just what I was getting at, thank you. I can convert the units
