Strategic Deconfliction

Strategic Deconfliction is the process of ensuring that one flight does not conflict with another at the time of planning. Conflicts can consider both time and 3-Dimensional (3D) space, therefore flights are permitted to share the same 3D space as long as they are significantly separated in time. To do this, flights are compared to any existing flights using Flightplans (in the Accepted state) as well as other means of reserving or otherwise restricting airspace.

This functionality is useful in both planning for singular flights or to help coordinate a fleet operation with an enhanced level of safety.

Caution

Via can only perform Strategic Deconfliction between Flightplans that it has knowledge of and therefore cannot guarantee that a Flightplan is free of conflicts. It is advised that the operator performs their own checks prior to flight and confirm with the relevant authorities.

4-Dimensional Volumes

4-Dimensional (4D) Volumes are are volumes in 3D space that also consider a time range in which they may be considered “active”. As such a 4D Volume is comprised of coordinates in 2D space (defined in WGS84 latitude and longitude) that form a closed shape, a lower and upper altitude bounding as well as start and end times which correspond to an earliest entry time and latest exist time respectively. These volumes are designed to conform to the standard as described in ASTM F3548-21. A 4D Volume is typically created considering a number of factors:

• The expected true position (considering ground speed and time of departure)
• Errors contained within the flight operation attributed to the navigation, pathing and instrumentation which may apply both vertically and laterally
• Variability of external factors such as wind
• Any expected required manoeuvring and by extension the capabilities of the aircraft to achieve them

Many 4D Volumes can belong to a single Flightplan and provide a way to assess the expected occupied space of an aircraft at any given time or within any given time range, effectively segmenting the flightplan into sections which are “active” or not. Many 4D Volumes may be “active” at any one time and may overlap spatially within the same Flightplan to account for the range of uncertainties which may occur both prior and during flight, it is therefore expected that the start and end times for subsequent 4D Volumes as well as their 3D space will overlap.

These volumes are the fundamental basis for how Via can ensure that two Flightplans are not able to contravene each other such that they are strategically deconflicted.

During the planning phase it is assumed that a flight will stay within these volumes to a high level of confidence and therefore they may be reliably used to perform strategic deconfliction prior to flight.

Tip

Airspace Constraints also provide a mechanism to create arbitrary 4D volumes to meet operational needs without creating a Flightplan.

Conflict Detection

To determine whether a conflict exists, Via compares both the spatial and temporal extent of 4D Volumes against each other to determine any overlap in 3D space or time that occurs between 4D Volumes that do not belong to the same Flightplan. If any such conflict exists, a Flightplan cannot be moved in to the state Accepted.

Within the Web Application, conflicts are displayed with red 4D Volumes and changing the time will indicate that 2 or more volumes have an overlap in space and time. When this occurs, the “Submit” button will not allow the Flightplan to be changed to the Accepted state.

Conflict Resolution

Strategic Deconfliction in Via is handled using 2 mechanisms which achieve the same goal of calculating an updated Flightplan which no longer has a conflict.

Temporal Deconfliction

Temporal deconfliction does not change any of the positional information contained within a Flightplan. Instead, it preserves the original waypoints by only advancing the departure time to the next available departure time that would result in no conflicts. This process is useful for when a prescribed routing is key to an operation and deviation from it is not acceptable.

Deconfliction with Pathing

When the precise route is not required, the original Flightplan can be deconflicted using Pathing. A key feature of Via’s Pathing algorithm is the ability to produce a result that does not contain any conflicts. The original waypoints of a Flightplan can be treated as “Checkpoints” for Pathing, which means the result will contain these waypoints but also insert additional waypoints that augment the flightpath around any occupied airspace as described by any existing 4D Volumes.

This feature can be access by using the UTM checkbox when performing pathing via the Web Application or creating a pathing task using the API.