Free Flight Geometry

Geometry Information for Uploaded Parts

The geometry can be split over multiple files. There are seven different types of parts; therefore, a separate file needs to be created for each of these geometry types and include only the appropriate parts for that category. Do not duplicate parts across the geometry files to be used in one simulation. Be sure to confirm that your uploaded geometry has forward-facing direction in the -X axis direction of it's coordinate system. A MainWing part is required for the simulation.

Use the instructions on the 'Uploading Geometry' page to upload parts. For each part (geometry file) you upload, you will be required to select a geometry type. The following is a list of available types:

  • Fuselage (default settings) - This is the main body of the aircraft or vehicle.
  • WingElements - This would include any flaps, pylons, and slats that is part of the Main Wing. Flaps can also be uploaded as a Hinge Element.
  • Tail - This type includes the horizontal and vertical stabilizers. Rudder can also be uploaded as a Hinge Element.
  • Engine - This type is associated with the outer casting of an aircraft engine.
  • Spinner - Any geometry that would typically spin (ie. wheels).
  • LandingGear - It includes any geometry associated with the landing gear system including any struct and truss.
  • MainWing - This is a required geometry for the simulation. It includes only the main wing geometry. Any other part associated with the main wing is assigned as a Wing Element geometry type.
  • Radiators - The radiator type is made up of two parallel planes that represent the up and down stream faces of the actual radiator core. This will need to fully intersect the geometry around it so that it forms a fully sealed volume. More information can be found here.
  • Hinge-Element - Any part that can rotate about a rotational axis. The app will report the moment forces on the hing-element relative to the rotational axis. The hinge-element angle can be configured in the application settings when it is selected as part of a simulation. Any control surface, including flaps and rudder, can be uploaded as a Hinge Element geometry.

Be sure to separate your geometry into these groupings prior to upload. All files should be the same scale and the relative position of the parts should be consistent across all files.

Details for Required Geometry Attributes

Inputs are required for three of the geometry types: MainWing, Hinge Element, and Radiator.


The chord length is generally the Mean Aerodynamic Chord and should be entered in meters. The wing area should be entered in squared meters. The main wing type can have multiple files if uploading slats, flaps, and pylons separately.

Note: If uploading flap, slat, and pylon geometry separately, the attributes will just be the same as the attributes for the main wing.

Hinge Elements

The starting and ending points (meters) of the rotation axis are required for each Hinge Element geometry. The App will rotate the Hinge Element geometry by the rotation angle (entered in Run Setup) about the Rotation Axis defined in the Geometry Attributes.


Required inputs include the normal direction vector of the downstream face of the radiator, the Inertial Coefficient, and Viscous Coefficient of the Radiator are also required.

Additional details for radiators can be found here.