Part 14: Model Aircraft Missions with Aviator

STK Premium (Air) or STK Enterprise
You can obtain the necessary licenses for this tutorial 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.

This lesson requires STK 12.1 to complete it in its entirety. It includes new features introduced in STK 12.1.

Capabilities Covered

This lesson covers the following STK Capabilities:

  • STK Pro
  • Aviator

Problem Statement

Aircrew mission planners require analytical tools that allow them to determine how atmospheric phenomena and terrain will affect the performance of an airborne mission. Furthermore, they need the ability to use the analytical tool to model real-world aircraft performance that accounts for variations in airframe performance characteristics and mission requirements. In this lesson, mission planners will fly a small commuter jet from Colorado Springs Municipal Airport to Telluride Regional airport. They will quickly add Navigational Aids as waypoints. They will determine how much fuel is required, and how much payload can be carried on board the aircraft in a fast, easy way.

Solution

  • Use STK and STK's Aviator capability to design a cross country flight route.
  • Use the Aviator Catalog Manager to:
    • Load airfield runway data into the scenario for takeoff and landing procedures.
    • Load Navigational Aids (NAVAIDs) to simulate physical devices on the ground that aircraft can detect and fly to.
  • Use selected Data Providers to determine payload requirements and how much fuel is consumed during the flight.

What You Will Learn

Upon completion of this tutorial, you will understand the following:

  • Aviator Catalog Manager
  • Aviator Propagator
  • Aviator Tools
  • How to create Analytical Objects from the Aviator Catalog Manager and Aviator

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

  1. Launch STK ().
  2. In the Welcome to STK window, click Create a Scenario.
  3. Enter the following in the New Scenario Wizard:
    4. Option Value
    Name: STK_Aviator
    Location: Default
    Start: 1 Aug 2020 18:00:00.000 UTCG
    Stop: + 1 hr
  4. When you finish, click OK.
  5. When the scenario loads, click Save (). A folder with the same name as your scenario is created for you in the location specified above.
  6. Verify the scenario name and location.
  7. Click Save.

Declutter the Labels

Your analysis will take place in very mountainous terrain which can obstruct object labels. Use Label Declutter to separate the labels on objects that are in close proximity for better identification in small areas.

  1. Bring the 3D Graphics window to the front.
  2. Open the 3D Graphics window properties ().
  3. On the Details page, select Enable for Label Declutter.
  4. Click OK to accept the changes, and close the Properties Browser.

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 mission elements has an associated catalog in STK. The Aviator Catalog Manager is a utility that allows you to view the contents of catalogs, create new items, copy or edit existing items, and search for specific items.

  1. Extend the Utilities menu.
  2. Select the Aviator Catalog Manager.
  3. Expand Runway.
  4. Select ARINC424 runways.
  5. To the right, click the Use Master Data File ellipses ().
  6. Select My Computer.
  7. Browse to C:\Program Files\AGI\STK 12\Data\Resources\stktraining\samples.
  8. Select the FAANFD18 file.
  9. Click Open.
  10. On the Aviator Catalog Manager, click Save.
  11. Keep the Aviator Catalog Manager open.

Determine the Length of a Runway

The aircraft will fly to and land at Telluride Regional Airport. Determine the length of the runway.

  1. In the upper left corner of the Aviator Catalog Manager, enter Telluride in the Filter: field.
  2. Click Enter.
  3. Select TELLURIDE RGNL 09 27 in the list under ARINC424 runways.

    4. When looking at runway data in the Aviator Catalog Manager, the two numbers next to the runway are reciprocal headings of the runway. 09 is 90 degrees (points east) and 27 is 270 degrees (points west). If there is more than one runway pointing in the same direction (parallel runways), each runway is identified by appending left (L), center (C) and right (R) to the number to identify its position (when facing its direction)—for example, runways one-five-left (15L), one-five-center (15C), and one-five-right (15R).

  4. On the right, you will see data concerning the runway. Locate Length. The runway at Telluride Regional Airport is 7111 feet long.

Insert Analytical Objects from the Aviator Catalog Manager

A small commuter jet will takeoff from Colorado Springs Municipal Airport and land at Telluride Regional Airport. The Telluride Regional Airport runway sits on a plateau and dips slightly in the center which can provide a challenging landing for the pilot. Weather conditions in the area often rapidly change, and pilots must be aware of issues impacting the airfield such as high terrain which exceeds 14,000 feet as well as the runway's location on a plateau with a thousand-foot drop should the aircraft slide off of the runway. Use the Aviator Catalog Manager to insert the Colorado Springs Municipal Airport and the Telluride Regional Airport as Place () objects into the scenario.

  1. Under ARINC424 runways, right click on TELLURIDE RGNL 09 27.
  2. Select Create STK Object from waypoint...
  3. Change Type of object: to Place in the Create STK Objects window.
  4. Change Color: if desired.
  5. Click OK.
  6. In the upper left hand side of the Aviator Catalog Manager, type Colorado Springs in the Filter: field.
  7. Click Enter.
  8. Right click on CITY OF COLORADO SPRINGS MUNI 17L 35R in the list under ARINC424 runways.
  9. Select Create STK Object from waypoint.
  10. Change Type of object: to Place in the Create STK Objects window.
  11. Change Color: if desired.
  12. Click OK.
  13. When finished, close () the Aviator Catalog Manager.

Situational Awareness

Now that you have the center points of both runways entered as Place () objects, you can quickly zoom to them to view the runways and surrounding terrain features.

  1. Bring the 3D Graphics window to the front.
  2. Right click on CITY_OF_COLORADO_SPRINGS_MUNI_17L_35R in the Object Browser, and select Zoom To.
  3. Use your mouse to change the view so that you can view the runway and its surroundings.

    4. Colorado Springs Runway and Surroundings

  4. Right click on TELLURIDE_RGNL_09_27 in the Object Browser, and select Zoom To.
  5. Use your mouse to change the view so that you can view the runway and its surroundings.

Telluride Runway and Surroundings

Insert An Aircraft

Insert an Aircraft () object which you will use to create a flight plan.

  1. Using the Insert STK Objects tool, insert an Aircraft () object using the Insert Default () method.
  2. Rename the Aircraft () object "Flight_Plan".
  3. Open Flight_Plan's () Properties ().

Aviator

Aviator provides an enhanced method for modeling aircraft - more accurate and more flexible than the standard Great Arc propagator. With Aviator, the aircraft's route is modeled by a sequence of curves parametrized by well-known performance characteristics of aircraft, including cruise airspeed, climb rate, roll rate, and bank angle. The precise state of an aircraft at any given time can be computed analytically - swiftly and without excessive data storage needs.

  1. On the Basic - Route page, change the Propagator to Aviator.
  2. Click Apply.
  3. Click Optimize STK for Aviator on the Flight Path Warning pop up window. This also changes the animation time to X-Real Animation Time Mode.

    4. 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.

  4. Click OK to close the Fight Path Warning window.

Mission Window

The mission window is used to define the aircraft's route when Aviator has been selected as the propagator. The mission window contains three toolbars - Initial Aircraft Setup, Phases of Flight, and Procedures and Sites - that enable you to define the aircraft that you are modeling and to create, modify, and delete phases and procedures. The mission list provides an overview of the mission by listing each of the mission phases and the procedures within them, in the order in which they will be executed. The mission profile can display a variety of data describing the mission.

Initial Aircraft Setup - Select Aircraft

The buttons on the Initial Aircraft Setup toolbar are used to define the aircraft model that will be used in the mission. The basic models found in Select Aircraft window are representative of an aircraft type, but not a specific aircraft. It's up to you to customize the model you choose to match actual aircraft characteristics. This is an introduction to Aviator so you will make some minor changes.

  1. In the Initial Aircraft Setup toolbar, click Select Aircraft.

    2. Initial Aircraft Setup Toolbar - Select Aircraft

  2. Right click on Basic Business Jet, and select Duplicate.
  3. Right click on Basic Business Jet Copy, and select Rename.
  4. Rename Basic Business Jet Copy to FlightPlan.
  5. Ensure FlightPlan is selected, and click OK.

Initial Aircraft Setup - Aircraft Properties

Aircraft Properties provide access to performance models. Performance models are used to define the behavior of the aircraft in flight. By specifying performance models to use with each phase of the mission, you can vary the manner in which the aircraft performs based on the priorities of the mission. You'll use default settings mostly.

  1. In the Initial Aircraft Setup toolbar, click Aircraft Properties ().

Acceleration Performance Model

The Basic Acceleration performance model is comprised of three tabs:

  • Basic: define the basic turning, climb and descent transition, and attitude characteristics of the aircraft
  • Aerodynamics: select and define strategies to model attitude characteristics
  • Propulsion: select and define strategies to model propulsion characteristics

You want to determine how much fuel is consumed during the flight.

  1. Select the Acceleration Built-In Model in the Performance Models section.
  2. Ensure the Basic tab is selected.
  3. In the Level Turns section, open the pull down menu and select Scale by atmosphere density.
  4. In the Climb and Descent Transitions section, select Scale by atmosphere density in the drop down menu.
  5. Select the Aerodynamics tab.
  6. Change the Strategy: to Basic Fixed Wing.
  7. Select the Propulsion tab.
  8. Change the Strategy: to Basic Fixed Wing.
  9. Click Save.

Notice that the Mode: is set to Jet - Specify Net Thrust. You will use the default values for both aerodynamics and propulsion, but they will have an affect on fuel consumed. All of this data would be changed according to the actual specifications of your aircraft.

Climb Performance Model

The Basic Climb performance model is comprised of a simple set of parameters that define the flight characteristics of the aircraft while climbing.

  1. Select the Climb Built-In Model in the Performance Models section.
  2. Select Use Aero/Propulsion Fuel Flow.
  3. Click Save.

Cruise Performance Model

The Basic Cruise performance model is comprised of a simple set of parameters that define the flight characteristics of the aircraft during level flight. Since this is a fairly short flight, the aircraft will climb to 25000 feet and level off.

  1. Select the Cruise Built-In Model in the Performance Models section.
  2. Change the Default Cruise Altitude: to 25000 ft.
  3. Select Use Aero/Propulsion Fuel Flow.
  4. Click Save.

Descent Performance Model

The Basic Descent performance model is comprised of a simple set of parameters that define the flight characteristics of the aircraft while descending.

  1. Select the Descent Built-In Model in the Performance Models section.
  2. Enable Use Aero/Propulsion Fuel Flow.
  3. Click Save.

Landing Performance Model

The Basic Landing performance model is comprised of a simple set of parameters that define the flight characteristics of the aircraft during a landing.

  1. Select the Landing Built-In Model in the Performance Models section.
  2. Enable Use Aero/Propulsion Fuel Flow.
  3. Click Save.

Takeoff Performance Model

The Basic Takeoff performance model is comprised of a simple set of parameters that define the flight characteristics of the aircraft during a takeoff.

  1. Select the Takeoff Built-In Model in the Performance Models section.
  2. Enable Use Aero/Propulsion Fuel Flow.
  3. Click Save.
  4. Click Close.
  5. Click Apply to apply changes, and keep the Properties Browser open.

Initial Aircraft Setup - Configuration

The Configuration window is used to define the aircraft's fuel and payload configuration.

  1. In the Initial Aircraft Setup toolbar, click Configuration().
  2. Change the Empty Weight: value to 31000 lb. This is where you add payload weight. This will account for the pilot, instructor, and baggage.
  3. Note the Max Landing Weight value. If, at the end of the analysis, the Aircraft () object weighs more than this value, a warning will appear in Message Viewer.
  4. Note the Total Weight value. This is the empty weight and the fuel load of the Aircraft () object.
  5. Select the Stations tab.
  6. Click Internal Fuel.
  7. Note the Capacity and Initial state values. After your initial analysis, you may need to adjust the initial state.
  8. Click OK.
  9. Click Apply to apply changes, and keep the Properties Browser open.

Initial Aircraft Setup - Mission Wind Model

Use the Wind and Atmosphere Model tool to simulate wind and atmospheric conditions for the scenario, a mission, a specific procedure, or a group of selected procedures.

  1. In the Initial Aircraft Setup toolbar, click Mission Wind Model ().

    2. For the purposes of this scenario you will use a constant bearing and speed for your wind. If you were mission planning on the current day, you would want to consider using the NOAA ADDS Service model. The NOAA ADDS Service wind model allows you to use forecasts from the Aviation Digital Data Service (ADDS), provided by the National Oceanic and Atmospheric Administration (NOAA), to define the wind effect.

  2. Change the Wind Bearing: value to 180 deg.
  3. Change the Wind Speed: value to 20 nm/hr.
  4. Click OK.
  5. Click Apply to apply changes, and keep the Properties Browser open.

Flight Plan

In this scenario, you will use one phase. You can have multiple phases, if you desire. Each phase can contain a separate performance model for the Aircraft (). The aircraft will takeoff from Colorado Springs Municipal Airport and fly direct to Blue Mesa VOR/DME. A VOR/DME is a radio beacon that combines a VHF omnidirectional range (VOR) with a distance measuring equipment (DME). Turning at Blue Mesa VOR/DME, the aircraft will fly to Cones VOR/DME, and begin its final approach and land at Telluride Regional Airport.

Site Properties - Select Runway

If you have ARINC424 airport data available in the Aviator Catalog Manager, you can define a site using an airport in that data.

  1. In the Mission List window, right click on Phase 1 and select Insert First Procedure for Phase ().
  2. Select Runway from Catalog () in the Site Properties / Select Site Type: section.
  3. Enter Colorado Springs in the Filter: field.
  4. Click Enter.
  5. Under ARINC424 runways, select CITY OF COLORADO SPRINGS MUNI 17L 35R.
  6. Click Next.

Procedure Properties - Takeoff

A Takeoff procedure launches an aircraft from a runway site into the air.

  1. Select Takeoff () in the Procedure Properties window / Select Procedure Type: section.
  2. Set the following:
    3. Option Value
    Name: COS Runway
    Use runway heading The direction that the aircraft is pointing. 172 Mag 180 True (Headwind) enabled
    Runway Altitude Offset: 7 ft
    Use Terrain for Runway Altitude enabled
  3. Click Finish.
  4. Click Apply to apply changes, and keep the Properties Browser open.

Site Properties - End of Previous Procedure

The end of the previous procedure can be used as a waypoint to define the site of the next procedure. In this instance, due to terrain, you want to gain altitude prior to flying to Blue Mesa VOR/DME.

  1. Right click on CITY OF COLORADO SPRINGS MUNI 17L 35R in the Mission List, and select Insert Procedure After ().
  2. Select End of Previous Procedure () in the Site Properties window / Select Site Type: section.
  3. Change the Name: to Climb.
  4. Click Next.

Procedure Properties - Basic Maneuver Climb Before Turning

A Basic Maneuver procedure is a single action undertaken by the aircraft. It is unlike most procedures in Aviator, which represent sets of actions that together comprise a common flying procedure.

  1. Select Basic Maneuver () in the Procedure Properties window / Select Procedure Type: section.
  2. Change the Name: to Straight 20 nm.
  3. In the Horizontal / Navigation tab settings, note that the strategy: is set to Straight ahead. Open the pull down menu to view other strategies.
  4. Set the following :
    5. Option Value
    Strategy: Straight Ahead (default)
    Basic Stop Conditions - Time of Flight: disable
    Basic Stop Conditions - Downrange: 20 nm
  5. Select the Vertical / Profile tab.
  6. Set the Altitude - Mode: to Specify Altitude Change.
  7. Set the Altitude - Relative Altitude Change: value to 10000 ft.
  8. Click Finish two times.
  9. Click Apply to apply changes, and keep the Properties Browser open.

Site Properties - Navaid Fly to Blue Mesa

If you have ARINC424 navaid data available in the Aviator Catalog Manager, you can define a site using a navaid from that data.

  1. Right click on Climb in the Mission List, and select Insert Procedure After ().
  2. Select Navaid from Catalog () in the Site Properties window / Select Site Type: section.
  3. Enter HBU in the Filter: field. HBU is the FAA designator for Blue Mesa VOR/DME.
  4. Click Enter.
  5. Right click on HBU, and select Create STK Object from waypoint...
  6. Set Type of object: to Place.
  7. Change the Color: if desired.
  8. Click OK.
  9. Click Next.

Procedure Properties - Basic Point to Point

A Basic Point to Point procedure is a basic traverse between two waypoints.

  1. Select Basic Point to Point () in the Procedure Properties window / Select Procedure Type: section.
  2. Set the following:
    3. Option Value
    Name: Blue Mesa
    Navigation Options - Nav Mode: Fly Direct
    Enroute Options - Turn Factor 5.00 (less roll)
  3. Click Finish.
  4. Click Apply to apply changes and keep the Properties Browser open.

Site Properties - Navaid Fly to Cones

  1. Right click on HBU in the Mission List, and select Insert Procedure After ().
  2. Select Navaid from Catalog () in the Site Properties window / Select Site Type: section.
  3. Enter ETL in the Filter: field.
  4. Click Enter.
  5. Right click on ETL, and select Create STK Object from waypoint...
  6. Set Type of object: to Place.
  7. Change the Color: if desired.
  8. Click OK.
  9. Click Next.

Procedure Properties - Basic Point to Point

  1. Select Basic Point to Point () in the Procedure Properties window / Select Procedure Type: section.
  2. Set the following:
    3. Option Value
    Name: Cones
    Altitude - Use Aircraft Default Cruise Altitude clear
    Altitude - Altitude: 15000 ft
    Enroute Options - Turn Factor 5.00
    Enroute Cruise Airspeed - Pull-down menu Other Airspeed
    Enroute Cruise Airspeed - Airspeed: 250 nm/hr
  3. Click Finish.
  4. Click Apply to apply changes and keep the Properties Browser open.

Site Properties - Select Runway

  1. Right click on ETL in the Mission List, and select Insert Procedure After ().
  2. Select Runway from Catalog () in the Site Properties / Select Site Type: section.
  3. Enter Telluride in the Filter: field.
  4. Click Enter.
  5. Select TELLURIDE RGNL 09 27 under ARINC424 runways.
  6. Click Next.

Procedure Properties - Landing

A Landing procedure brings an aircraft down from the air to a runway site.

  1. Select Landing () in the Procedure Properties window / Select Procedure Type: section.
  2. Set the following:
    3. Option Value
    Name: Telluride Runway
    Approach Mode: Intercept Glideslope
    Use runway heading 096 Mag 105 True (Headwind) selected
    Runway Altitude Offset: 7 ft
    Use Terrain for Runway Altitude selected
  3. Click Finish.
  4. Click Apply to apply changes and leave the Properties Browser open.

Message Viewer

STK uses the Message Viewer window to display error messages, warning messages, and informational messages. Currently, there is a warning in Message Viewer.

  1. In the STK Menu area, open the View menu and select Message Viewer. Look at the last message. Expand as necessary. The maximum landing weight for the aircraft is 40000 pounds. It is to heavy.

    2. Message Viewer Warning

  2. At the bottom of Message Viewer, you'll see a tab named All Messages. Right click on the All Messages tab and select Clear All Tabs.
  3. Close () the Message Viewer.

Flight Profile by Time Custom Report

The data provider Flight Profile By Time has the elements required for your analysis. Flight data is sampled using a constant time step between grid points. This report style is only available for Aviator propagated vehicles.

  1. In the Object Browser, right click on Flight_Plan (), and select the Report & Graph Manager.
  2. In the Styles list, right click on the Flight Profile by Time report and select Properties.
  3. In the Report Contents list, select Flight Profile By Time-Fuel Consumed. This opens the Flight Profile By Time Data Provider on the left.
  4. In the Flight Profile By Time Data Provider, move () Fuel State and Weight elements to the Report Contents list.
  5. Click OK.
  6. Click OK to close the Warning.
  7. In the Styles list, expand the My Styles folder.
  8. Right click the Flight Profile by Time report in the My Styles folder, and select Rename.
  9. Rename the report "My Flight Profile by Time".
  10. Click Generate

    11. First and last lines of Flight Profile by Time report

    Focusing on fuel consumed, fuel state and the weight of the aircraft, you can see that the plane is approximately 3238 pounds above its maximum landing weight of 40000 lbs when it touches down. You landed with approximately 12238 pounds of fuel.

  11. Leave the My Flight Profile by Time report open.

Adjust the Initial Fuel State

You have the option of adjusting the initial fuel state and payload. In this instance, adjust the initial fuel state. Keep in mind you want reserve fuel. You landed with approximately 12238 pounds of fuel. Remove 6000 pounds of fuel.

  1. Return to Flight_Plan's () Properties ().
  2. In the Initial Aircraft Setup toolbar, click Configuration ().
  3. Select the Stations tab in the Aircraft Configuration window.
  4. Select Internal Fuel.
  5. Change the Initial state: value to 14000 lb.
  6. Click Apply.
  7. Click OK.
  8. Click OK to close Flight_Plan's () Properties Browser.

Refresh the My Flight Profile by Time Report

  1. Bring the My Flight Profile by Time report to the front.
  2. Refresh () the report.

    3. Adjusted Flight Profile by Time

    Focusing on fuel consumed, fuel state and the weight of the aircraft, you can see that the plane is approximately 2614 pounds below its maximum landing weight. You landed with plenty of reserve fuel. Furthermore, you needed less fuel to arrive at your destination.

  3. Look at Message Viewer. Due to adjusting the weight of the aircraft, there are no new warnings.
  4. When finished, close () the report and the Report & Graph Manager.
  5. Close () the Message Viewer.

2D Graphics Window Flight Route View

Use the 2D Graphics window to get a good view of the flight route.

  1. Bring the 2D Graphics window to the front.
  2. Zoom in until you can see the flight route

2D Graphics Window View of the Flight Route

View the Flight

Use the 3D Graphics window to observe the mission.

  1. Bring the 3D Graphics window to the front.
  2. Reset () the scenario.
  3. Zoom To Flight_Plan.

    4. Aircraft on Runway

  4. Adjust (, ) the time step as desired.
  5. Start () the scenario.
  6. When finished, Reset () the scenario.
  7. You can Zoom To ETL and HBU to view the actual VOR/DME ground transmitter sites.

Summary

You began by loading and saving of aircraft, airports, navaids, runways, VTOL points, and waypoints using the Aviator Catalog Manager. Using Aviator, you mission planned for a small commuter jet taking off from Colorado Springs Municipal Airport and landing at Telluride Regional Airport. During the initial aircraft configuration, you added 1000 pounds to the aircraft to account for increased payload. You tweaked performance models to determine how much fuel was required for the flight. The wind bearing for the entire mission was out of the south at 20 miles per hour. After takeoff, you flew straight ahead to gain altitude due to mountainous terrain. After 20 miles, you turned and flew direct to Blue Mesa VOR/DME. Making a slight turn, you continued to Cones VOR/DME. You were able to line up the aircraft by arriving at Cones with a heading taking you directly to Telluride. After landing in Telluride, you viewed a warning in Message Viewer that informed you of the aircraft's weight being over the maximum allowed weight of 40,000 pounds. You then used a customized Flight Profile by Time report to determine how much the aircraft weighed during landing and how much fuel you still had on board. Returning to the aircraft configuration settings, you adjusted the initial fuel load. Re-analyzing the mission, you were able to land in Telluride under the maximum allowable weight limit with plenty of reserve fuel.

On Your Own

Throughout the tutorial, hyperlinks were provided that pointed to in depth information of various tools and functions. Now's a good time to go back through this tutorial and view that information. You can continue to adjust performance models and reanalyze the mission. Use a different aircraft model, and try different procedure types. In this scenario, you flew straight ahead for 20 nautical miles. Try some barrel rolls or loops. Have some fun.