Aviator VTOL and Terrain Following

STK Premium (Air) or STK Enterprise
You can obtain the necessary licenses for this training by contacting AGI Support at support@agi.com or 1-800-924-7244.

The results of the tutorial may vary depending on the user settings and data enabled (online operations, terrain server, dynamic Earth data, etc.). It is acceptable to have different results.

Capabilities Covered

This lesson covers the following STK Capabilities:

  • STK Pro
  • Aviator

Problem Statement

Aircrew mission planners need analytical tools to determine how atmospheric phenomena and terrain will affect the performance of an airborne mission. Furthermore, they need the analytical tool to model real-world aircraft performance, such as variations in airframe performance characteristics and mission requirements. You are using STK to create a pre-brief of a future check-ride for a new helicopter pilot who will be flying search and rescue (SAR) missions in the vicinity of Mount Whitney. The check-ride will consist of taking off from a local helipad, navigating to three checkpoints, and returning back to the helipad for a landing. Part of the check-ride will demonstrate the pilot's ability to fly above the terrain (terrain following) at 1000 feet above ground level (AGL) altitude. You will use STK to familiarize the student pilot with the flight route and terrain features prior to the actual check ride.

Solution

Using STK's Aviator capability, create a flight path using a modified STK Basic helicopter model. Load terrain for analysis and situational awareness in the 3D Graphics window using a local STK terrain file installed on your hard drive. Use the Aviator Catalog Manager to takeoff from and land at a local helipad in the city of Ridgecrest, CA. If you have an internet connection, load three (3) Place objects using the Search Toolbar. If you don't have an internet connection, load three (3) place objects using the Define Properties method to use as waypoints for the check-ride. Wind conditions will be added to the scenario. Finally, create a custom dynamic report that will display important flight data in the 3D Graphics window.

Video Guidance

Watch the following video. Then follow the steps below, which incorporate the systems and missions you work on (sample inputs provided).

Create a New Scenario

Create a new scenario using the default analysis time period.

  1. Click the Create a Scenario () button.
  2. Enter the following in the New Scenario Wizard:
    3. Option Value
    Name Aviator_VTOL
    Location C:\Users\<username>\Documents\STK 12\
    Start 1 Aug 2020 19:00:00.000
    End + 75 min
  3. When you finish, click OK .
  4. When the scenario loads, click Save (). A folder with the same name as your scenario is created for you in the location specified above.
  5. Verify the scenario name and location and click Save .

SAVE OFTEN!

Add Terrain

Add analytical terrain from a local file. Microsoft Bing Maps can be used for imagery. However, imagery is not required.

  1. Open the scenario object’s properties (Aviator_VTOL).
  2. Browse to the Basic – Terrain page.
  3. Clear the Use terrain server for analysis check box.
  4. Click OK .
  5. Launch the Globe Manager () from the 3D Graphics window toolbar.
  6. Extend the Add Terrain/Imagery () menu on the Globe Manager toolbar.
  7. Select Add Terrain/Imagery (Add Terrain/Imagery button).
  8. Click the ellipsis () button and navigate to <STK Install Folder>\Data\Resources\stktraining\imagery.
  9. Select PtMugu_ChinaLake.pdtt.
  10. Click Yes when prompted to Use Terrain for Analysis.

Declutter the 3D Graphics Window

Since you're using terrain in the 3D Graphics window, a common user preference is to use Label Declutter. It declutters labels away from the central body and towards the viewer, keeping the labels from being obscured by the terrain.

  1. Bring the 3D Graphics window to the front.
  2. Right click on the 3D Graphics window and select Properties ().
  3. On the Details page, find the Label Declutter field and select the Enable check box.
  4. Click OK .

Aviator Catalog Manager

Aviator provides a catalog structure for the loading and saving of aircraft, airports, navaids, runways, VTOL points, and waypoints. Each of these elements of a mission has an associated catalog in STK.

  1. Extend the Utilities menu.
  2. Select the Aviator Catalog Manager.
  3. Expand Runway, and select ARINC424 runways.
  4. Click the Use Master Data File () button.
  5. Browse to <STK install folder>\Data\Resources\stktraining\samples.
  6. Select the FAANFD18 option.
  7. Click Open.
  8. On the Aviator Catalog Manager, click Save .
  9. Close the Aviator Catalog Manager.

Add the Waypoints

There are multiple ways to design waypoints in STK. For this scenario, you will fly direct to waypoints that can easily be inserted into your scenario using the Place () object and the Search Tool or the Define Properties method. The Search toolbar can search within online Standard Object Databases and Microsoft BingTM for satellites, facilities, and places and allows you to create satellite, facility, place, and area target objects from the results that it returns.

If you have an internet connection, use the Search tool to add the following place objects into the scenario.

  • Dunmovin, CA
  • Olancha Peak, CA
  • Mount Whitney, CA

Search Toolbar

  1. In the Search Toolbar, enter Dunmovin.
  2. Double click on Dunmovin, CA. This enters Dunmovin, CA as a Place () object into the scenario.
  3. In the Search Toolbar, enter Olancha Peak.
  4. Double click on Olancha Peak, CA.
  5. In the Search Toolbar, enter Mount Whitney.
  6. Double click on Mount Whitney, CA.

Add Waypoints Manually (if desired)

 

If you don't have an internet connection, use the Define Properties () methods to add waypoints to the scenario. The steps are below to help you.

  1. Insert a Place () object using the Define Properties () method.
  2. On the Basic - Position page, make the following Position field changes:
Option Value
Latitude: 36.0963 deg
Longitude:

-117.965 deg
  1. Click OK .
  2. Rename the Place object "Dunmovin."
  3. Follow steps 1-3 to add OlanchaPeak and MountWhitney to the scenario as well. Here are their latitude and longitudes:
Option Value
OlanchaPeak Latitude: 36.2665 deg
OlanchaPeak Longitude: -118.117 deg
Option Value
MountWhitney Latitude: 36.5789 deg
MountWhitney Longitude: -118.291 deg

Aviator

Now that you have added waypoints you can fly to, it's time to plan the mission using Aviator. You will add wind, build a popular type of high altitude rescue helicopter, and create a flight path to and from Mount Whitney.

  1. Insert an Aircraft () object using the Insert Default method.
  2. Rename the Aircraft object CheckRide.
  3. Open CheckRide's () properties ().
  4. On the Basic - Route page, change the Propagator to Aviator.
  5. Click Apply .

Flight Path Warning

Aviator performs best in the 3D Graphics window when the surface reference of the globe is set to Mean Sea Level. You will receive a warning message when you apply changes or click OK to close the properties window of an Aviator object with the surface reference set to WGS84. It is highly recommended that you set the surface reference as indicated before working with Aviator.

  1. When the Flight Path Warning window opens, click Optimize STK for Aviator . This also changes the animation time to X-Real Animation Time Mode.
  2. Click OK .

Mission Window

The Mission window is used to define the aircraft's route when Aviator has been selected as the propagator.

List and Profile

Initial Aircraft Setup toolbar

The buttons on the Initial Aircraft Setup toolbar are used to define the aircraft model that will be used in the mission.

Mission Wind Model

The Mission Wind Model icon opens the Wind / Atmosphere Model window. The Wind and Atmosphere Model tool allows you to simulate wind and atmospheric conditions for the scenario, a mission, a specific procedure, or a group of multi-selected procedures.

  1. Click the Mission Wind Model () icon.
  2. Change Model Type: to Constant Bearing/Speed.
  3. Change Wind Speed to 20 nm/hr
  4. Click OK .
  5. Click Apply .

View the Wind in the Mission Profile

As you build the mission, you can view the wind in the Mission Profile.

  1. Right-click in the Mission Profile.
  2. Select Profile Options/Properties.
  3. Select the Secondary Y Axis check box.
  4. From the Secondary Y Axis list, select Course Crosswind.
  5. Click OK .

Select Aircraft

Select the aircraft to be used for the Mission.

  1. Click the Select Aircraft () button on the Initial Aircraft Setup toolbar.
  2. On the Select Aircraft window, right-click on Basic Helicopter.
  3. Select Duplicate.
  4. Rename the Basic Helicopter Copy, "CheckRide."
  5. Ensure CheckRide is selected and click OK .
  6. Click Apply .

Enable Terrain Following

You want to ensure the aircraft follows the terrain. To do this, you need to enable the Terrain Follow performance model.

  1. Click the Aircraft Properties () button on the Aircraft Setup toolbar.
  2. When the CheckRide window appears, right-click in the Performance Models: field and select Add New Model Type.
  3. In the Add New Model Type window, click TerrainFollow in the Models: field. This automatically moves it to the New Types: field.
  4. Click OK .
  5. Click Save.
  6. Click Close.
  7. Click Apply.

Model Helicopter General Characteristics

You are modeling a high altitude rescue helicopter. The helicopter's empty weight is 3951 pounds. You will add 2000 pounds to that total to account for crew and equipment. Let's input the properties.

  1. In the Initial Aircraft Setup Toolbar, click Configuration ().
  2. Make the following changes on the Basic tab.
    3. Option Value
    Empty Weight: 5951 lb
    Max Landing Weight: 7903 lb
  3. Select the Stations tab.
  4. Click Internal Fuel.
  5. Make the following changes in the order shown:
    6. Option Value
    Initial state: 1500 lb
    Capacity: 1530 lb
  6. Click Apply.
  7. Click OK .

Performance Models

Continue building the helicopter to specifications.

  1. In the Initial Aircraft Setup Toolbar, click Aircraft Properties ().
  2. In the Performance Models: section, select Climb - Built-In Model.
  3. Change the Altitude Rate: to 1600 ft/min.
  4. In the Performance Models: section, select Cruise - Built-In Model.
  5. Change the Default Cruise Altitude to 15000 ft.
  6. Make the following changes to Max Performance:
    7. Option Value
    Airspeed: 131 nm/hr
    Fuel Flow: 560 lb/hr
  7. In the Performance Models: section, select TerrainFollow - AGI TerrainFollow Model.
  8. Make the following changes to Max Performance:
Option Value
Airspeed: 131 nm/hr
Fuel Flow: 560 lb/hr
  1. In the Performance Models: section, select VTOL - Basic Model.
  2. In the Translation Maneuvers section, change Rate to 25 nm/hr.

    3. You are using a constant wind speed of 20 nm/hr. The Translation Maneuver Rate default is approximately nine (9) nm/hr. Since you will be taking off into the wind, you need to compensate for the strong headwind.

  3. Click Save and then click Close .
  4. Click Apply .

Specify Phase Performance Models

Select Performance Models for the aircraft to be applied only to the current Mission Phase. In this case, you need to link Terrain Following to the catalog.

  1. Click the Phase Properties () button.
  2. On the Phase 1 properties window, locate the Model Type column.
  3. Right-click on TerrainFollow and select Link to Catalog.
  4. When the Link to Catalog (TerrainFollow) window appears, click OK .
  5. Click OK to close the Phase 1 properties window.

Takeoff Procedure

You are taking off from a helipad. You can model that helipad using the Aviator Catalog Manager and selecting it.

  1. In the Mission List, right-click on Phase 1.
  2. Select the Insert First Procedure for Phase () option.
  3. In the Select Site Type: field select VTOL Point from Catalog ().
  4. Type Ridgecrest in the Filter: field and press the Enter key.
  5. Select SCE RIDGECREST SERVICE CENTER H1 and click Next > .
  6. In the Select Procedure Type: field, select Vertical Takeoff.
  7. In the Heading The direction that the aircraft is pointing. field, select the Heading into Wind check box.
  8. Click Finish .
  9. Click Apply .

Forward Flight

  1. In the Mission List, right-click on Vertical Takeoff.
  2. Select Insert Procedure After ().
  3. In the Select Site Type: field, select End of Previous Procedure.
  4. Click Next > .
  5. In the Select Procedure Type: field, select Transition to Forward Flight.
  6. In the Transition Course section, select the Transition into Wind option.
  7. Click Finish , then click Apply .

Add STK Object Waypoints

An STK Object Waypoint is used to define a waypoint at or relative to the position of another object within the scenario at a specific time.

Proceed to Dunmovin

  1. In the Mission List, right-click on Transition to Forward Flight.
  2. Select Insert Procedure After ().
  3. In the Select Site Type: field, select STK Object Waypoint.
  4. Change the Name: to Dunmovin.
  5. In the Link To: field, select Dunmovin.
  6. Click Next > .
  7. In the Select Procedure Type: field, select Basic Point to Point.
  8. In the Enroute Options section, change the Turn Factor: value to 5.00. A higher value increases the turn radius to minimize the bank angle required to complete the turn.
  9. In the Enroute Cruise Airspeed section, select Max Performance Airspeed from the drop down.
  10. Click Finish , then click Apply .

Proceed to Olancha Peak

  1. In the Mission List, right-click on Dunmovin.
  2. Select Insert Procedure After ().
  3. In the Select Site Type: field, select STK Object Waypoint.
  4. Change the Name: to Olancha.
  5. In the Link To: field, select Olancha Peak.
  6. Click Next > .
  7. In the Select Procedure Type: field, select Basic Point to Point.
  8. In the Enroute Options section, change the Turn Factor: value to 5.00.
  9. In the Enroute Cruise Airspeed section, select Max Performance Airspeed from the drop down.
  10. Click Finish , then click Apply .

Terrain Following to Mount Whitney

  1. In the Mission List, right-click on Olancha.
  2. Select Insert Procedure After ().
  3. In the Select Site Type: field select STK Object Waypoint.
  4. Change the Name: to Whitney.
  5. In the Link To: field, select Mount Whitney.
  6. Click Next > .
  7. In the Select Procedure Type: field, select Terrain Following.
  8. Change AGL Altitude: to 1000 ft
  9. In the Terrain Following Airspeed section, select Max Performance Airspeed from the drop down.
  10. Click Finish , then click Apply .

Reverse Point to Point

After arriving at Mount Whitney, the pilot will turn and fly back to Ridgecrest to land. To save time and not rebuild the reverse course, you can use Reverse Point to Point Procedure order. The Reverse Point to Point Procedure Order tool computes reverse versions of all of the currently selected point to point procedures and copies them to the clipboard. You can use this tool to automatically create a return flight path along the original outbound route and then paste it into your mission.

  1. In the Mission List, right-click on Whitney.
  2. Extend the Tools and Wizards menu.
  3. Select the Reverse Point to Point Procedure Order option.
  4. When the Reverse Point to Point Procedures window appears, click OK .
  5. In the Mission List, right-click on Whitney.
  6. Select Insert Procedure After ().
  7. In the Select Site Type: field, select Super Procedure.
  8. Click Next > .
  9. Click Load Procedures from Clipboard .
  10. Click Finish , then click Apply .

Land at Ridgecrest

  1. In the Mission List, right-click on Super Procedure Site.
  2. Select Insert Procedure After ().
  3. In the Select Site Type: field select VTOL Point from Catalog ().
  4. Type Ridgecrest in the Filter: field and press the Enter key.
  5. Select SCE RIDGECREST SERVICE CENTER H1.
  6. Click Next > .
  7. In the Select Procedure Type: field, select Transition to Hover.
  8. Change Altitude to AGL and the value to 50 ft.
  9. In Transition Options section, select the Transition into Wind check box.
  10. Click Finish , then click Apply .

Vertically Land Back at Ridgecrest

  1. Right-click on Transition to Hover.
  2. Select Insert Procedure After ().
  3. In the Select Site Type: field, select VTOL Point from Catalog ().
  4. Type Ridgecrest in the Filter: field and press the Enter key.
  5. Select SCE RIDGECREST SERVICE CENTER H1.
  6. Click Next >
  7. In the Select Procedure Type: field, select Vertical Landing.
  8. Change Heading - Mode: to Heading into Wind.
  9. Click Finish , then click Apply .

Mission List and Mission Profile

When you have finished building your mission, you can view your procedures and profile in the mission window.

Completed Mission List and Mission Profile

Fuel Consumed

If you recall, you began the mission with 1500 pounds of fuel. You can easily check how much fuel is remaining when you land.

  1. In the Mission List, right-click on Vertical Landing.
  2. Select the Profile Data at Final State option.
  3. Locate Fuel Consumed and note the value.
  4. Close the data window.
  5. Click OK to close CheckRide's () properties ().

Create a Custom Report

At this point, you can zoom to CheckRide and play the scenario to see how each procedure looks in the 3D Graphics window. When you are finished, add a custom dynamic display to the 3D Graphics window that shows mission parameters for the flight.

  1. Right-click on CheckRide () and open the Report & Graph Manager ().
  2. In the Styles section, select the Show Reports check box and clear the Show Graphs check box.
  3. Right-click on the My Styles folder.
  4. Expand the New menu and click Report.
  5. Name the report Mission Profile and press the Enter key to open the report's properties.
  6. Expand () the Flight Profile By Time Data Provider.
  7. Move () the following data providers to the Report Contents list in the following order:
    • Time
    • DownRange
    • Altitude
    • Altitude-AGL
    • FuelConsumed
  8. Click OK and close the Report & Graph Manager.

If required , you can add any data providers of interest. Since you're going to put this report on the 3D Graphics window, it's a good idea to only insert a few parameters.

Add a Data Display

  1. Open CheckRide's () properties () and browse to the 3D Graphics - Data Display page.
  2. Click Add... .
  3. In the Add a Data Display window, locate and select the Mission Profile report in the Styles field.
  4. Click OK .
  5. You can modify the look of the display if required using the Position, Appearance, and Background fields.
  6. When you are finished, click OK .

If you reset and then play the scenario, you can see the Mission Profile information on the 3D Graphics window.

Data Display

Summary

You began the scenario by turning off Terrain Server and loading a local terrain file to be used both analytically and visually. You loaded a Federal Aviation Administration National Aeronautical Navigation Services Nation Flight Database (FAANFD) which you used to locate a helipad used for a takeoff and landing. You employed the Search Tool to find three locations and insert them into STK as analytical objects. These Place () objects functioned as waypoints for the helicopter mission. After inserting an Aircraft () object, you changed the propagator to Aviator. You changed wind conditions to mimic wind direction and speed normally seen along the flight route. Modifying the basic helicopter model, you changed weights, fuel load and flight characteristics which defined the type of helicopter used during an actual mission. You added terrain following as a performance model. You were introduced to pulling data from the FAANFD using the VTOL point search to locate and use a helipad. For the outbound portion of the flight, you created basic point to point procedures between multiple waypoints and then switched to terrain following. When returning to base, you chose to use a Reverse Point to Point procedure. Next you created a custom report and imbedded the data into the 3D Graphics window to be used during a briefing.

 

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