1 Problem description - The Challenge of Airspace Incursions in Europe
Airspace incursions represent a significant and growing problem in several European countries, including Denmark, Poland, and Estonia. These incidents involve unauthorized or unexpected entries into controlled airspace, which can disrupt air traffic management and pose safety risks.
The closure of airspace has profound cascading effects, primarily manifesting as:
Flight cancellations, as avoiding the closed airspace is not feasible due to increased flight time and fuel costs.
Flight diversions and delays, as routing through adjacent sectors is not the optimal flight path.
Additional flight cancellations, as routes through adjacent sectors may lack sufficient capacity.
Increased congestion in neighboring regions, which impacts other international routes and potentially forces rerouting and operational disruptions for flights not directly affected by the airspace closure.
2 Our goal: simulating airspace closures and estimate impact
Simulate and estimate several KPIs that give an idea of the impact in the network. For instance, given a concrete airspace clousure, defined by a concrete airspace polygon and a minimum and maximum flight level and a time start - time end of clousure, we want to estimate:
How many flights are crossing on 1 day, 1 week, certain period that particular airspace.
How many of those flights are candidate for re-routing? for instance estimating that anybody that requires to fly more than xx% for distance will be cancelled. In general sectors closed will not be so large that flying around them is not feasible.
How would the en-routed flights overload the adjacent sectors? For instance, if we model the flight around the impacted area, what kind of demand we see in adjacent sectors (i.e. HEC, OCC). Are those numbers reasonable to they imply extra delays in the network?
3 Key variables to consider:
Scope of the Closure
Extent of airspace affected: Entire FIR/UIR, selected sectors, or specific vertical layers (e.g., only above FL300).
Type of closure: Complete (no traffic permitted), partial (certain routes or levels remain available), or restricted to specific categories (state, emergency, humanitarian).
Traffic Characteristics
Current traffic volume: flows, peak vs. off-peak periods.
Traffic mix: Long-haul overflights vs. regional flights, cargo vs. passenger.
Route dependency: Percentage of flights that normally transit this ANSP compared with those originating or terminating inside it.
Operational Coordination
Adjacent ANSP interaction: Capacity of neighbouring FIRs to absorb rerouted traffic, sector capacity limits, required coordination procedures.
Alternative routings: Availability of pre-defined contingency routes or established diversion corridors.
Flow management measures: Possible level capping, sequencing, or miles-in-trail restrictions applied by neighbouring ANSPs.
Temporal Factors
Advance notice: Whether the closure is pre-announced (e.g., strike, planned maintenance) or sudden (e.g., security incident).
Estimated duration: Known time window versus indefinite closure; uncertainty drives more conservative rerouting and capacity planning.
Flights Already Airborne
Proximity to the closed airspace: Aircraft about to enter may require immediate reroutes or holding.
Fuel and endurance margins: Ability to accept longer diversions or level changes.
ATC workload: Real-time tactical coordination between upstream sectors and airline operations centres.
Network-Wide Effects
Knock-on congestion: Neighbouring FIR capacity and staffing levels, potential for cascading delays.
Airport impact: Diversions to alternate airports, stand availability, and local curfews.
Military or restricted areas: Possibility of temporarily opening additional routes to absorb traffic.
Regulatory & Political Context
State agreements or bilateral arrangements for emergency overflight rights.
Charges and cost implications for airlines when rerouting significantly increases distance or fuel burn.
4 Course of action:
MVP0 Proposal for Airspace Closure Simulation
To develop the Minimum Viable Product (MVP0) for simulating airspace closures, the following steps are proposed:
Select Dataset: Use data from Austria (a large region where firehose or radar sources can be utilized interchangeably for this purpose).
Choose Timeframe: Select a specific day and time range for the airspace closure.
Define Closure Area: Establish the specific area that will be closed.
Generate Simulated Data: Create simulated data based on the actual data from the selected day, ensuring that flights avoid the closure zone. (Note: Consideration is needed for flights potentially within the zone at the time of closure—what happens to those?)
Visualize in Bravo5: Display the information in Bravo5 (replay), highlighting simulated data in a distinct color or similar method; present without labels, focusing solely on flights.
Add Complexity Layer: Overlay a color-coded layer in Bravo5 to represent the complexity of each region.
Full development:
Define the Scope: Establish an airspace object for study and select a sector to close. This will be designed generically to enable worldwide application of the tool.
Select Time Slot: Choose a study period, such as one day, one week, or both.
Access Dataset: Transfer the sample dataset (e.g. 1 day) to DataBeacon’s infrastructure and interpolate the data (noting that ADS-B Exchange samples occur every 5 minutes). In the future, we would implement a different access method for a faster access.
Compute Impacted Flights: Identify the number of flights that would need to cross the airspace during the closure period.
Re-route Flights: Deviate the impacted flights and re-route them through adjacent sectors.
Simulation Scenario 1: Assume all flights are accepted by adjacent sectors; compute the resulting demand and complexity in those sectors, and evaluate feasibility (i.e., whether all traffic demand can be absorbed).
Simulation Scenario 2: If sectors become overloaded, delay select flights to later time slots with lower demand; estimate the resulting airline delays.
Visualize Results: Generate two videos using our replay tool (Bravo5) to visually depict overloaded sectors and delayed flights.
Produce Report: Compile a report summarizing the simulation results.
Additional Consideration: Identify historical dates when airspace was closed and obtain relevant data for those periods.