hawk37,
My only contention was with the statement that a stopped aircraft is producing no power.
In any analysis of Power, you have to be very careful to consider whether you are looking at the engine alone, or the engine/airframe combination. From the point of view of aircraft performance, we are only interested in the engine/airframe combination, and Ta (Thrust
AVAILABLE after all other losses).
If we examine the engine standing alone, for a stationary aircraft with Takeoff Engine Power / Thrust applied, the total Power produced within the engine is enormous. This includes the internally required power for engine operation (far in excess of that which is useful for a turbine engine), noise and heat generation, operation of accessories such as generators, hydraulic pumps etc. Thus, the engine is internally producing significant power, and a lot of Thrust, whether you are speaking of the Jet, Turbo-Prop, or Piston-Prop. Maximum Thrust is also being produced, but, as the aircraft is not moving, the engine/airframe combination is producing no Power, in other words, performance is Zero. The same can be said for the hovering helicopter.
This is all alluded to in the quote that I made from the QANTAS P/E manual, and from the excellent link provided by
CaptYanknBank.
Aircraft performance is all about Thrust AVAILABLE (Ta), not the power produced within the engine/s viewed in isolation to the engine/airframe combination.
Regards,
Old Smokey