A Basic Cruise performance model is comprised of a simple set of parameters that define the flight characteristics of the aircraft during level flight.
| Field | 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. |
| Default Cruise Altitude | The aircraft's default cruising altitude. You cannot specify an altitude below sea level (0). If a procedure is specified that requires the aircraft to fly below sea level, the performance models in effect at sea level will be applied to that procedure. |
| Airspeed Type | The airspeed reference of the performance model - 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. |
| Use Aero/Propulsion Fuel Flow | Select 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 to scale the fuel flow based on the aircraft's actual altitude. If the airspeed type is TAS, then fuel flow will decrease as the altitude of the aircraft increases. If this option is disabled, the fuel flow will be calculated at the Default Cruise Altitude (if available), or at sea level. |
| Minimum | The minimum cruising airspeed and fuel flow. |
| Max Endurance | The cruising airspeed and fuel flow that will provided the maximum flying time possible for the aircraft. |
| Maximum | The maximum cruising airspeed and fuel flow. |
| Max Range | The cruising airspeed and fuel flow that will provided the maximum flight range possible for the aircraft. |
| Max Performance | A custom performance airspeed and fuel flow that you can use to model specific flight conditions. The values must be between the Minimum and Maximum parameters. |
Make Speeds and Fuel Valid
The fuel flow values for Minimum and Maximum airspeed both need to be greater than the fuel flow values for Maximum Endurance and Maximum Range airspeed. If you have specified Maximum Endurance or Maximum Range fuel flows that are invalid in this respect, you can click the Make Speeds and Fuel Valid button to automatically correct these values to be at least one percent greater than the Minimum and Maximum airspeed fuel flows. The computation is performed using the following steps:
- Aviator evaluates the specific ranges of the current Minimum, Maximum, and Max Range airspeed and fuel flow values, and increases the largest of those specific ranges by one percent.
- The computed specific range value is then used to compute the fuel flow for Max Range.
- The current Max Endurance fuel flow is compared to the computed Max Range fuel flow, and the lesser fuel flow value is applied.