A Basic Descent performance model is comprised of a simple set of parameters that define the flight characteristics of the aircraft while descending.
| Parameter | Description |
|---|---|
| Ceiling Altitude | The maximum altitude above Mean Sea Level that may be specified as a procedure altitude for the aircraft. The ceiling describes the maximum altitude at which an aircraft can sustain level, non-accelerated flight. In general, an aircraft will not exceed the ceiling, but the ceiling could be violated by STK's Aviator capability in some instances, where required to complete a maneuver. |
| Airspeed | The aircraft's speed; select a reference from the drop-down menu - true airspeed (TAS True Airspeed: the speed that the aircraft is moving relative to the airmass that it is flying in.), calibrated airspeed (CAS Calibrated Airspeed: the speed reported by the airspeed indicator, corrected for position and instrument error.), equivalent airspeed (EAS Equivalent Airspeed: the airspeed at sea level (International Standard Atmosphere) at which the dynamic pressure is equal to the dynamic pressure at the aircraft's current true airspeed and altitude.), or Mach The ratio of the aircraft's speed and the speed of sound at the aircraft's altitude, with local atmospheric conditions. number. |
| Altitude Rate | The constant rate at which the aircraft will climb and descend once established in a steady climb or descent. |
| Use Aero/Propulsion Fuel Flow | Select this check box to use the fuel flow calculated by the aerodynamics and propulsion strategies defined in the active acceleration performance model; if the acceleration performance model is not set to calculate fuel flow, then fuel flow will not be calculated for this performance model, either. |
| Scale Fuel Flow by Non Std Density | Select this check box to scale the fuel flow based on the aircraft's actual altitude. If this option is disabled, the fuel flow will be calculated at the Default Cruise Altitude (if available), or at sea level. |
| Sea Level Fuel Flow | The amount of fuel used per unit of time selected, at sea level. |
| Initial Level Off for Acceleration | If enabled, the aircraft will level off and accelerate or decelerate until its airspeed is within the defined Relative airspeed tolerance, and only then begin its climb or descent. This models the common pilot practice of achieving the aircraft's optimal climb or descent airspeed at level flight before beginning a climb or descent. |