bishop99
To offer another perspective.
- A Jet engine is an internal combustion engine. An internal combustion engine burns a ratio of fuel against the mass of air (O2) used in combustion.
- A jet engine is most efficient at high RPM (>90%).
- At sea level and lower levels the engine produces power in excess of that needed to achieve VMO/MMO in level flight.
- As the aircraft climbs, the mass airflow reduces due to the air density decreasing, ergo, the amount of fuel burned for a given engine speed decreases.
- Thrust also decreases with altitude for a given engine speed, conveniently so too does drag.
Last edited by Capt Claret; 4th April 2006 at 01:03.