AIRSPACE / KNOWLEDGE & DESIGN
Route Planning and Conflict Detection | Working with space that has a time dimension
The shortest distance alone doesn't decide it. Rule out anything that breaks a hard constraint first, then choose the route that best fits the mission from what remains.
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Separate constraints from preferences
Once you think about sharing operational intent, a route has to be treated as a volume of space with timestamps attached. From here on, this is our own design proposal for route planning. It is not an algorithm that demonstrates conformance to any aviation standard or the safety of a real aircraft.
Source: FAA | UTM Pilot Program| Category | Examples | How it is handled in the computation |
|---|---|---|
| Hard constraints | Restrictions on the airspace, the aircraft's operating limits, permitted time windows, and so on | Exclude any candidate that violates them |
| Values to optimize | Time, estimated energy use, congestion, and so on | Compare the remaining candidates |
| Unknown conditions | Missing weather data, insufficient terrain accuracy, and so on | Hold as unknown and send for confirmation |
| Contingency conditions | Alternate sites and plans for loss of link | Evaluate separately from the normal route |
The unit of conflict is a volume with a time
Two lines crossing on a map mean something different if they cross at different times. On the other hand, even when the planned times differ, you still have to account for delays and position error. Instead of using raw points and lines, model the spatial and temporal uncertainty appropriate to each aircraft and operation.
Conceptual model
V_A(t): the space aircraft A may occupy at time t
V_B(t): the space aircraft B may occupy at time t
If, at any point in the evaluated time window,
V_A(t) ∩ V_B(t) is non-empty
→ treat it as a potential planning conflict
Important: this formula does not determine the buffer sizeIf you compare at coarse time steps, you can miss aircraft passing each other between steps. Design for intersection over continuous intervals, conservative bounds, and an assessment of sampling error. Never let the convenience of the screen decide the separation standard for real operations.
From generating candidates to committing
- 1. Check the inputs and the freshness of the data; if anything is unknown, hold for confirmation.
- 2. Generate candidate volumes of space and time that are permitted.
- 3. Keep only the candidates that satisfy the aircraft and mission conditions.
- 4. Detect potential conflicts with other operational intents.
- 5. Compare with an objective function and return candidates with reasons attached.
- 6. At the moment of commit, re-check the data version and conflicts.
If two people pick the same time window at the same moment, you must not tell both of them "reserved". The commit step has to stay consistent, and if the plan version has gone stale, send it back for recalculation.
What to show the user: comparisons and limits
| What to show | Example wording |
|---|---|
| Reason for a candidate | Shifting the departure time reduces potential planning conflicts |
| Scope of the data | Evaluated against plan information from participating services |
| Unconfirmed | Constraint information for this area could not be retrieved |
| Actions | Change the date and time, view the conditions, ask the person in charge |
Do not present anything as a guarantee that there will be no collision. Say what was evaluated and what remains open. Being able to compute a route candidate and being able to fly safely are two different things, and the second needs its own checks.
DEFINITION OF DONE
Before you ship, check these.
- Time offsets and head-on passes can be tested.
- Unknown airspace information is never converted into "no constraints".
- Concurrent commits cannot let two conflicting reservations both succeed.
Design checkpoints for spec reviews and acceptance testing.
Check the sources
Explanations of rules and definitions draw on the references below. The screens, data models, and definition of done are our own design proposals.
- FAA | UTM Pilot ProgramDemonstrations including the exchange of operational intent and airspace information
Sources checked on September 30, 2026. For your specific case, please confirm with the latest official information.