A Basic Maneuver procedure is a single action undertaken by the aircraft. It is unlike most procedures in STK's Aviator capability, which represent sets of actions that together comprise a common flying procedure.
A Basic Maneuver is the product of interactions between the horizontal and vertical plane strategies, the speed control strategy, and the aerodynamic and propulsion aspects of the aircraft. The strategies provide standard methods to control the procedure, but they cannot guarantee every possible combination. It is possible for you to select options that are not simultaneously enforceable.
Therefore, you should consider the Basic Maneuver's properties to be specifications, not certainties. Confirm the actual result of the procedure from the data values that are provided in the Mission Profile. If the results do not match your expectations, you can review the messages in the Message Viewer for more information about how the procedure was computed.
Horizontal / Navigation
The Horizontal / Navigation strategy of a Basic Maneuver defines the primary action that the aircraft will perform. Some Horizontal / Navigation strategies allow you to specify a Vertical / Profile strategy, while others - those identified as 3D - determine both the horizontal and vertical maneuvering of the aircraft.
Click Help Me Choose to review brief descriptions of the available strategies. Click Copy to save the currently defined strategy to the clipboard; click Paste to define the strategy in this tab with properties currently saved to the clipboard.
Vertical / Profile
Vertical / Profile strategies can be specified for non-3D maneuvers. If you have selected a 3D maneuver for the Horizontal / Navigation strategy, then the Vertical / Profile tab will simply continue to display the selected Horizontal / Navigation strategy; in this situation, you can modify the strategy from this tab, but you will be unable to select a different strategy.
Click Help Me Choose to review brief descriptions of the available strategies. Click Copy to save the currently defined strategy to the clipboard; click Paste to define the strategy in this tab with properties currently saved to the clipboard.
Attitude / Performance / Fuel
The Attitude / Performance / Fuel tab provides controls for the type of flight that the aircraft is flying, its fuel flow, and propagation properties.
| Field | Description |
|---|---|
| Flight Mode |
The type of performance that is most applicable to the maneuver. Select a mode that correlates to the type of performance model that best suits the maneuver that the aircraft is flying. If you are modeling VTOL flight, select the Rotary Wing / Hover mode. In addition, the VTOL limits for altitude and forward flight TAS True Airspeed: the speed that the aircraft is moving relative to the airmass that it is flying in. must be satisfied, the body Z-axis of the aircraft must within 10 degrees of vertical, and you must select the VTOL Perf Model method for Fuel Flow Source. |
| Fuel Flow Source |
The method that will be used to determine fuel flow during the maneuver.
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| Override Fuel Flow | If you have selected the Override method for Fuel Flow Source, this field allows you to enter the Fuel Flow rate. In addition, you can select Scale fuel flow by density 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. |
| Thrust Model Fuel... | If you have selected the Thrust Model method for Fuel Flow Source, click this button to define the Boost and Sustain fuel consumed and time limit properties that will be used to calculate the fuel flow rate. |
| Attitude Smooth Mode |
Controls the degree of smoothing that is performed when using a guidance strategy against a target that is using external ephemeris data to define its route. Smoothing corrects for discontinuities in the ephemeris data, but is a computationally intensive process; potentially prohibitively so for very large ephemeris files. If the ephemeris file includes the SmoothData keyword with the value, "Yes", then the procedure will not attempt smoothing, regardless of your selection for this control.
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| Start Attitude Blend Time | The amount of time that the aircraft will spend transitioning from the attitude of the previous procedure to the attitude at the beginning of the maneuver. |
| Control Time Constant | A smoothing constant for the performance of control surfaces; a large value increases control gains, while a small value decreases control gains. If you are observing roll oscillations or wobbling in the aircraft's flight path, a lower value for this property should reduce or eliminate the effect. |
Basic Stop Conditions
Each Basic Maneuver requires at least one stopping condition, which dictates when the maneuver will end regardless of whether any other goals are met. You can define more than one stopping condition if you want, and the maneuver will be stop if any one of them is met.
| Field | Description |
|---|---|
| Fuel State | A minimum amount of fuel remaining before the aircraft will stop the maneuver. |
| Time of Flight | A maximum duration that the aircraft will fly the maneuver. |
| Downrange | A maximum ground distance that the aircraft will fly. |
Ceiling
The Ceiling control enables you to define how Aviator will respond if the maneuver attempts to exceed the aircraft's ceiling. Select Continue if ceiling exceeded to ignore a ceiling violation, Error when ceiling exceeded to make the procedure invalid if the ceiling must be violated, or Stop when ceiling exceeded to stop the maneuver at the maximum altitude.
Surface
The Surface control enables you to define how Aviator will respond if the maneuver intersects the terrain. Options include:.
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Continue if terrain impacted- Ignores a terrain intersection.
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Error when terrain impacted- Makes the procedure invalid if the terrain is intersected.
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Stop when terrain impacted- Stops the maneuver if the terrain is intersected.
Surface Alt Reference
The Surface Alt Reference control enables you to define the altitude reference for the Surface control. Options include:
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WGS84 (World Geodetic System 1984)
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MSL (Mean Sea Level)
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Terrain
Impact Time Offset
If the maneuver will be stopped, enter a time value in this field to define the duration before the terrain intersection at which the maneuver will actually be stopped.