Hi Markdem,
Italia has been considering the propeller, engine, airframe combination.
It's easier to consider:
"In a turboprop, power available is determined by the performance of the engine/propeller combination. Engine output is called shaft horsepower (SHP). Thrust horsepower (THP) is propeller output, or the power that is converted to usable thrust by the propeller. The ability of the propeller to turn engine output into thrust is given by its propeller efficiency (p.e.). Under ideal conditions, SHP would equal THP, but due to friction in the gearbox and propeller drag, THP is always less than SHP. Propeller efficiency is always less than 100%.
THP = SHP * p.e."
p.e. is not zero.
So even if the aircraft is stationary or the helicopter is hovering, there is definitely THP being produced if you are making SHP.