The power of a turbine engine does not only depend on air mass pumped through. It also depends on:
a) Temperature. If the same mass of air comes cooler to the combustion chamber, the engine deliveres more power due to better heating rate.
b) Ambient air pressure. If the exhaust gas has to fight against less ambient air pressure, the engine delivers more power.
The result is: At SAME density altitude, a turbine engine will deliver more power at high pressure altitude (that is low ambient air pressure) and therefore cool temperature.
Last edited by FixedRotaryWing; 10th January 2005 at 20:17.