The thrust lapse rate refers to the rate at which the thrust of a jet engine decreases with increasing altitude. As an aircraft ascends to higher altitudes, the air density decreases, which affects the engine’s ability to generate thrust. The thrust lapse rate quantifies this decrease in thrust relative to the altitude climbed.
Where:
- = Thrust at altitude
- = Thrust at sea level
- Lapse rate = Rate at which temperature decreases with altitude
- Altitude = Altitude at which thrust is being calculated
- Standard temperature at sea level = Temperature at sea level under standard atmospheric conditions