SORA 2.5 – ARC Assessment Report
Air Risk Class assessment based on SafeSky-derived traffic intelligence and representative operational data
Applicant and Contact Information
| Applicant company | Transdrone Company |
| Primary contact | Mr De Niro |
| Position | |
| Phone number | |
| Company address | |
| Operator registration | |
| Report prepared by | SafeSky traffic analytics support dataset |
1. Operation Overview
Mission Description
| Operation name | PowerLine Inspection |
| Operation type | VLOS |
| Operational area | |
| Coordinates | 0.0000°N, 0.0000°E |
| Horizontal footprint | |
| Maximum altitude | 5000 ft AGL |
Aircraft and Crew
| UAS model | |
| Propulsion | Electric |
| Pilot in command | Mr John |
| Additional personnel | Mrs Lee |
| Navigation support | GPS + visual line of sight |
| Planned time window | |
| Operation mode | ☐ Recurring operation ☑ Single operation |
2. Airspace Environment
| Element | Name | Distance | Status / Class | Operational relevance | Informed |
|---|---|---|---|---|---|
| Nearest local aerodrome | STOCKHOLM/SÖDERSJUKHUSET | 3.0 km north | Uncontrolled / general aviation | Relevant for occasional low-level GA traffic in wider area | ☐ |
| Nearest local aerodrome | STOCKHOLM/GAMLA STAN | 4.5 km north | Uncontrolled / general aviation | Relevant for occasional low-level GA traffic in wider area | ☐ |
| Nearest local aerodrome | STOCKHOLM/KAROLINSKA | 7.7 km north | Uncontrolled / general aviation | Relevant for occasional low-level GA traffic in wider area | ☐ |
| Nearest local aerodrome | STOCKHOLM/HUDDINGE SJUKHUS | 10.3 km south-west | Uncontrolled / general aviation | Relevant for occasional low-level GA traffic in wider area | ☐ |
| Nearest local aerodrome | STOCKHOLM/BROMMA | 10.8 km north-west | Uncontrolled / general aviation | Relevant for occasional low-level GA traffic in wider area | ☐ |
| Nearest local aerodrome | DANDERYD HOSPITAL | 12.3 km north | Uncontrolled / general aviation | Relevant for occasional low-level GA traffic in wider area | ☐ |
| Nearest heliport | STOCKHOLM/SKÅ-EDEBY | 19.9 km west | Uncontrolled / general aviation | Limited relevance at planned distance | ☐ |
| Nearest CTR | BROMMA CTR | 25.4 km north-west | Class 2 | Controlled airspace in wider area, limited direct impact | ☐ |
| Nearest CTR | ES-R102 HAGA | 10.3 km north | Class 8 | Controlled airspace in wider area, limited direct impact | ☐ |
| Nearest CTR | ES-R105 TUMBA | 15.9 km south-west | Class 8 | Controlled airspace in wider area, limited direct impact | ☐ |
| Nearest CTR | ES-R110 HUDDINGE | 10.0 km south-west | Class 8 | Controlled airspace in wider area, limited direct impact | ☐ |
| Nearest CTR | ES-R111 SÃRENTORP | 14.4 km north | Class 8 | Controlled airspace in wider area, limited direct impact | ☐ |
| Nearest CTR | ES-R112 VÃLLINGE | 22.0 km west | Class 8 | Controlled airspace in wider area, limited direct impact | ☐ |
| Nearest CTR | ES-R113 STOCKHOLM | 6.5 km north | Class 8 | Controlled airspace in wider area, limited direct impact | ☐ |
| Nearest CTR | ES-R21 SOUTHERN PART OF THE STOCKHOLM ARCHIPELAGO | 14.0 km south-east | Class 8 | Controlled airspace in wider area, limited direct impact | ☐ |
| Nearest CTR | ES-R24 DROTTNINGHOLM | 12.7 km north-west | Class 8 | Controlled airspace in wider area, limited direct impact | ☐ |
| Airspace element | ESAA FIR | 1093.6 km north | Class 8 | Contextual airspace element in the area | ☐ |
Note: Distances and classifications are derived from OpenAIP data. Limited to 20 km in the vicinity.
SORA 2.5 – ARC Assessment Report
Air Risk Class assessment based on SafeSky-derived traffic intelligence and representative operational data
Traffic Heatmap and SafeSky Traffic Snapshot
Representative traffic statistics extracted from SafeSky data.
Monthly Traffic Distribution
Total number of detected cooperative traffic tracks per month (2025-01-01 – 2025-01-10)
Seasonal increase is visible between May and September, consistent with recreational and fair-weather activity.
SORA 2.5 – ARC Assessment Report
Air Risk Class assessment based on SafeSky-derived traffic intelligence and representative operational data
3. Historical Traffic Characterisation (SafeSky Data Analysis)
Dataset Definition
| Data source | SafeSky platform (ADS-B / FLARM / MLAT aggregated data). More details in appendix. |
| Observation period | 2025-01-01 to 2025-01-10 |
| Area analysed | Stockholm |
| Altitude filter | 0 – 5,000 ft AGL |
| Days excluded | 0 |
| Confidence level | Moderate to good for GA and equipped cooperative traffic |
Traffic Metrics
| Average detected flights / day | 8.6 |
| Peak detected flights / day | 17 |
| Average flights / hour (active period) | 0.3 |
| Peak hour observed | Tuesday 12:00–13:00, 5 tracks |
| Tracks below 500 ft AGL | 41.5% |
| Unique aircraft detected | 65 |
Specific Measurements During Planned Operation Hours
| Aircraft type | Representative track ID | Altitude observed | Minimum distance to operation area | Date | Time window | Detection confidence |
|---|---|---|---|---|---|---|
| General aviation fixed wing | 4AA9F3 | 246 ft AGL | 3.2 km | 2025-01-07 | 12:20 UTC | High |
| Helicopter | 4AAA72 | 771 ft AGL | 2.2 km | 2025-01-03 | 17:56 UTC | High |
| Glider | - | - | - | - | No detection | Low |
| Balloon | - | - | - | - | No detection | Low |
| UAV / Drone | - | - | - | - | No detection | Low |
| Hang glider | - | - | - | - | No detection | Low |
| Paraglider | - | - | - | - | No detection | Low |
| Paramotor | - | - | - | - | No detection | Low |
| Gyrocopter | - | - | - | - | No detection | Low |
| Military | - | - | - | - | No detection | Low |
| Commercial / jet aircraft | 4AC8CC | 4,596 ft AGL | 2.3 km | 2025-01-08 | 11:04 UTC | High |
All relevant airspace user categories are listed. Absence of detected traffic does not guarantee absence of operations, especially for non-cooperative aircraft.
| Traffic type | Estimated share | Typical altitude band | Observed pattern |
|---|---|---|---|
| Commercial / jet aircraft | 63% | 371–4,793 ft AGL | Contextual only, limited relevance to low-level UAS conflict |
| General aviation fixed wing | 28% | 545–2,871 ft AGL | Transit and training flights |
| Helicopter | 11% | 669–3,396 ft AGL | Point-to-point routes and occasional medical priority flights |
SORA 2.5 – ARC Assessment Report
Air Risk Class assessment based on SafeSky-derived traffic intelligence and representative operational data
4. Nearby Traffic Behaviour and Airspace Complexity
Historical observations indicate a moderate level of surrounding air activity, with an average of approximately 8.6 unique aircraft detected per day within the defined area of operation. A non-negligible share of detected traffic (41.5%) has been recorded below 500 ft AGL, which is relevant for low-altitude UAS operations. A noticeable increase in activity is observed during weekends, particularly on fair-weather afternoons, suggesting recreational flight activity. Helicopter and rotorcraft traffic represents 10.8% of observed aircraft, indicating occasional low-level rotary-wing activity that may operate at variable altitudes without fixed routes. The proximity of controlled airspace (CTR) within 10 km influences the traffic flow and density in the surrounding area, with controlled departures and arrivals contributing to the observed traffic patterns.
Moderate local traffic densityLow-altitude activity detectedWeekend recreational peaksOccasional low-level helicopter activityNearby CTR boundaryPeak: Tuesday 12:00 UTC
5. Coverage via Ground Antennas in the Region
Regional Ground Reception Coverage
| Primary coverage model | SafeSky-supported cooperative signal reception network |
| Coverage reliability above 1,000 ft AGL | High |
| Coverage reliability 500–1,000 ft AGL | Moderate to high |
| Coverage reliability below 500 ft AGL | Variable depending on terrain masking and aircraft equipment |
Ground antenna coverage data is not yet available for this region. This section will be populated in a future release when SafeSky antenna network data becomes accessible.
Operational Flight Status
Green: Safe to operate under planned conditions.
Orange: Cautious operation required due to moderate traffic or partial coverage limitations.
Red: Flight not recommended or forbidden under current conditions.
Operational Interpretation
| Expected detection confidence | Good for equipped GA and helicopters in the local area |
| Main limitations | Non-cooperative traffic, very low-level tracks, intermittent equipment visibility |
| Use in SORA context | Supporting situational awareness, not sole means of collision avoidance |
The regional ground antenna environment provides a useful level of reception confidence for cooperative traffic analysis and historical pattern identification. Coverage is considered strong enough to support the characterization of surrounding air traffic, while remaining subject to the usual limitations of low-altitude signal masking, aircraft equipage variability, and non-cooperative traffic absence.
SORA 2.5 – ARC Assessment Report
Air Risk Class assessment based on SafeSky-derived traffic intelligence and representative operational data
6. Own eConspicuity Technology Used
Installed / Available Onboard Technologies
| Technology | Installed | Operational use |
|---|---|---|
| ADS-B | ☑ | Active during operations |
| Remote ID | ☑ | Regulatory identification broadcast |
| Others | ☐ | Not installed |
| SafeSky | ☑ | Active during operations |
| ADS-L | ☑ | Active during operations |
| Dronetag | ☑ | Active during operations |
Implementation Notes
| Primary eConspicuity stack | |
| Purpose | |
| Operational limitation | |
| Typical use phase |
The operator uses a mixed eConspicuity approach combining onboard or connected broadcast technologies with external traffic-awareness services. This layered setup contributes to operational awareness and traceability, while remaining supplementary to visual observation, local procedures, and the formal mitigations defined in the SORA assessment.
7. Initial ARC Assessment
| Assessment criterion | Finding | Impact on ARC |
|---|---|---|
| Traffic density in surrounding area | Moderate, with recurring local and transit activity (avg 8.6 aircraft/day) | Increases likelihood of air encounter |
| Low-altitude traffic (below 500 ft AGL) | 41.5% of traffic below 500 ft AGL — significant | Direct altitude overlap with planned UAS operation likely |
| Proximity to controlled airspace (CTR) | BROMMA CTR at 25.4 km north-west | Limited direct impact on operational volume |
| Temporal traffic variation | Weekend/weekday ratio: 1.7× — significant weekend increase | Planning should account for higher weekend traffic density |
| Overall air risk classification | Initial ARC determined as ARC-d based on above criteria | See §10 for residual ARC after mitigations |
Initial assessment outcome: ARC-d, based on surrounding traffic density, low-altitude encounters, and proximity to structured airspace.
SORA 2.5 – ARC Assessment Report
Air Risk Class assessment based on SafeSky-derived traffic intelligence and representative operational data
Interpretation note: Strategic = historical data used to prepare and justify the operation. Tactical = means used during operations to monitor and react in real time. Operational feedback = post-operation return of experience and reporting used to improve future missions.
8. Tactical Mitigation
| Mitigation | Type | Status | Implementation detail |
|---|---|---|---|
| SafeSky Live Traffic Awareness | Tactical | Applied | |
| NOTAM Publication | Strategic | Applied | |
| Transponder / Remote ID | Tactical | Optional / if installed |
9. Operational Feedback
Post-Operation Reporting
| Report after every mission | ☑ Required |
| Report after every risky operation | ☑ Required |
| Safesky Subscription | ☑ Active subscription used for traffic review and mission feedback |
| Archiving period | 24 months |
Operational Learning Loop
| Mission debrief | After every mission |
| Incident / anomaly escalation | Immediate notification to Chief Pilot + DGTA report |
| Database update | Post-flight logs uploaded within 24h |
| Use in SORA context | This report is part of the SORA 2.5 Specific Operations Risk Assessment |
Post-mission feedback is part of the operator's safety loop. Every mission generates a report, while risky operations require enhanced reporting and review. SafeSky subscription services may be used to retain traffic traces, compare planned versus observed conditions, and strengthen future operational assessments.
SORA 2.5 – ARC Assessment Report
Air Risk Class assessment based on SafeSky-derived traffic intelligence and representative operational data
10. Residual ARC Conclusion
Data Confidence & Limitations
- Data is derived from cooperative sources (ADS-B, FLARM, MLAT) and may not capture all non-equipped aircraft.
- Coverage depends on ground station density and may vary with altitude and geography.
- Short-term anomalies (events, fly-ins) may not be fully represented in historical averages.
- Analysis assumes representative weather conditions during the observation period.
- Residual risk assessment remains conservative to account for non-detected traffic.
Taking into account the compact VLOS geometry, strategic mitigations (NOTAM Publication), tactical mitigations (SafeSky Live Traffic Awareness), and the overall traffic environment analysis presented in this report, the residual air risk is considered adequately managed. The combination of a compact operational volume, moderate surrounding traffic density, and the applied mitigations supports a determination consistent with residual ARC-c for this specific mission profile.
SORA 2.5 – ARC Assessment Report
Air Risk Class assessment based on SafeSky-derived traffic intelligence and representative operational data
11. Authority Validation Process
Application Review Information
| Competent authority | — |
| Application reference | — |
| Date of submission | — |
| Reviewed by | — |
| Date of review | — |
| Latest authority action | — |
Validation Status
| Current status | Pending — not yet submitted to authority |
| Requested clarifications | — |
| Applicant response due by | — |
| Expected next step | Authority submission by operator |
Status Reference Guide
| Status | Description | Recommended interpretation |
|---|---|---|
| Approved | The authority has validated the application and accepted the operation under the stated conditions. | Operation may proceed within the approved scope and limitations. |
| Rejected | The authority has determined that the application is not acceptable in its current form. | A revised submission is required before the operation can be considered again. |
| Waiting for more information | The review is ongoing, but additional evidence, clarifications, or corrections have been requested. | Applicant should respond to all comments before reassessment. |
| Pending | The application has been received but has not yet reached a completed review step. | No operational authorization should be assumed at this stage. |
At the date of this report revision, the authority review process is considered ongoing. No final operational authorization should be assumed until the competent authority has formally issued an approval decision or equivalent written acceptance.
Approval of this application does not constitute any admission of liability. The drone operator retains full responsibility for the execution of all flights.