Piyo ๐Ÿฃ: Poppo, I heard CASA requires something called "SORA" for drone operations. What is it and how do I do a risk assessment?

What is SORA?

Definition

SORA (System for Assessing Hazards & Operability Risk) is CASA's standardized methodology for:
  • Identifying hazards in drone operations
  • Assessing risk levels
  • Determining necessary mitigations
  • Gaining CASA approval

Why SORA Exists

CASR Part 101 requires operators to demonstrate safety through risk analysis, not just follow prescriptive rules.

SORA allows:
  • Innovation in drone operations
  • Tailored approvals for unique operations
  • Evidence-based safety decisions
  • Scalable risk management
  • SORA Framework Overview

    SORA Assessment Levels (1โ€“5)

    CASA classifies drone operations into 5 risk levels:

    Level Risk Profile Example Operations
    1 Minimal Drone in isolated rural area, no people within 100m, VLOS
    2 Low Drone in suburban area, scattered people, daytime VLOS
    3 Medium Drone near mixed populated/unpopulated areas, light traffic
    4 High Drone in dense urban area, significant crowds, complex airspace
    5 Extreme Drone over critical infrastructure, major events, high population

    SORA Assessment Process

    Step 1: Identify Ground Hazards

    Ground hazards = things on the ground that could be harmed if drone crashes. Categories:
    1. People Hazards

    • Population density (isolated vs. urban)
    • Person density in flight area
    • Vulnerable people (children, elderly)
    • Static vs. mobile groups (events, traffic)

    1. Infrastructure Hazards

    • Buildings and structures
    • Power lines and electrical infrastructure
    • Telecommunications towers
    • Road/rail networks
    • Water features

    1. Environmental Hazards

    • Terrain (terrain complexity affects visibility)
    • Wind patterns (sheltered vs. exposed)
    • Weather conditions
    • Lighting conditions (day vs. twilight vs. night)

    Step 2: Identify Airborne Hazards

    Airborne hazards = other aircraft that could collide with your drone. Assessment factors:
    1. Airspace Classification

    • Class Aโ€“E (controlled) vs. Class G (uncontrolled)
    • Flight Information Service area
    • NOTAM requirements

    1. Expected Traffic

    • Commercial aircraft patterns
    • General aviation activity
    • Helicopter operations
    • Military activity

    1. Deconfliction Requirements

    • ATC coordination needed?
    • Flight notification timing
    • Frequency monitoring

    Step 3: Determine Risk Level

    Risk matrix = Ground Risk ร— Airborne Risk Simplified calculation:

    `` SORA Level = [Ground Hazard Severity] ร— [Ground Hazard Probability] + [Airborne Hazard Severity] ร— [Airborne Hazard Probability] ``

    Example 1: Isolated Rural Area
    • Ground hazards: Very low (no people, no infrastructure)
    • Airborne hazards: Low (minimal manned aircraft)
    • Result: SORA Level 1

    Example 2: Suburban Drone Inspection
    • Ground hazards: Medium (scattered homes, some people)
    • Airborne hazards: Medium (light general aviation)
    • Result: SORA Level 2โ€“3

    Example 3: Urban Delivery Service
    • Ground hazards: High (dense population, buildings, power lines)
    • Airborne hazards: High (commercial traffic, helicopter activity)
    • Result: SORA Level 4โ€“5 (rare approval)

    Step 4: Identify Mitigations

    Mitigations = actions to reduce risk. Categories:

    Mitigation Type Examples
    Operational Flight altitude limits, speed restrictions, VLOS requirements
    Technical Redundant systems, automatic landing, obstacle avoidance
    Procedural Weather monitoring, pre-flight checks, crew training
    Administrative Operating hours restrictions, geographic boundaries, crew authorization

    Key principle: Higher SORA levels = more mitigations required

    Step 5: Verify Mitigations Effective

    CASA requires:
    • Evidence that mitigations actually reduce risk
    • Testing/validation of systems
    • Documented training for crew
    • Maintenance procedures to ensure reliability

    Example: If claiming "automatic return-to-home" as mitigation:
    • Must demonstrate system tested (multiple flights)
    • Must show reliability (99%+ success rate)
    • Must document backup procedures (if RTH fails)
    • SORA Documentation Requirements

      ConOps (Concept of Operations) Document

      Mandatory for all commercial operations. ConOps describes:
      1. Executive Summary

      • Operation type (surveying, inspection, photography, etc.)
      • Location and airspace classification
      • Flight duration and frequency
      • Expected SORA level

      1. Operation Description

      • Detailed flight plan
      • Mission objectives
      • Equipment specifications
      • Crew roles and responsibilities

      1. Hazard Analysis

      • Ground hazards identified
      • Airborne hazards identified
      • Risk assessment (SORA level determination)

      1. Risk Mitigation Plan

      • Identified mitigations
      • Evidence of mitigation effectiveness
      • Contingency procedures
      • Emergency procedures

      1. Personnel & Training

      • Crew qualifications
      • Training requirements
      • Medical fitness standards
      • Currency requirements

      1. Operations Manual

      • Pre-flight procedures
      • Flight procedures
      • Emergency procedures
      • Post-flight procedures

      1. Safety Case

      • Argument that operation is acceptably safe
      • Reference to mitigations
      • Regulatory compliance statement

      ConOps Length & Complexity

      Typical ConOps:
      • Simple operations (Level 1โ€“2): 20โ€“30 pages
      • Complex operations (Level 3): 50โ€“80 pages
      • Advanced operations (Level 4): 100+ pages
      • SORA Examples by Operation Type

        Example 1: Real Estate Photography (Suburban Area)

        Operation Details:
        • Property: Suburban house (town of 50,000)
        • Duration: 30 minutes
        • Altitude: 100โ€“150 feet AGL
        • Equipment: DJI Air 3S

        SORA Assessment: Ground Hazards:
        • People: Medium (neighbors in adjacent properties)
        • Infrastructure: Medium (power lines nearby, houses)
        • Terrain: Low (flat, open)
        • Ground Risk Rating: MEDIUM

        Airborne Hazards:
        • Airspace: Uncontrolled (Class G)
        • Traffic: Low (light general aviation)
        • Deconfliction: Low (NOTAM not required)
        • Airborne Risk Rating: LOW

        SORA Level: 2 (Low risk) Mitigations:
        • โœ… Maintain VLOS (within 500m)
        • โœ… Maximum 150 feet altitude
        • โœ… No flying over people
        • โœ… Pre-flight weather check
        • โœ… Pre-flight airspace check
        • โœ… Two-person crew (pilot + observer)

        Approval: ReOC sufficient (no additional CASA approval needed)

        Example 2: Surveying in Regional Area (150 hectares)

        Operation Details:
        • Area: Rural farmland (30 km from nearest town)
        • Duration: 3 hours (multiple flights)
        • Altitude: 200โ€“300 feet AGL
        • Equipment: DJI Matrice 300 RTK

        SORA Assessment: Ground Hazards:
        • People: Low (isolated area, no people expected)
        • Infrastructure: Medium (power lines on property boundary)
        • Terrain: Low (flat farmland)
        • Ground Risk Rating: LOW-MEDIUM

        Airborne Hazards:
        • Airspace: Uncontrolled (Class G)
        • Traffic: Low (minimal aircraft activity)
        • Deconfliction: Low
        • Airborne Risk Rating: LOW

        SORA Level: 2 (Low risk) Mitigations:
        • โœ… Maintain VLOS
        • โœ… Avoid power lines (minimum 50m clearance)
        • โœ… Flight time limited to daylight hours
        • โœ… Pre-flight weather assessment
        • โœ… Observer present
        • โœ… GPS accuracy verification (RTK functioning)

        Approval: ReOC sufficient

        Example 3: Delivery Operations (Urban Area)

        Operation Details:
        • Area: City center (population 500,000)
        • Route: 10 km (downtown to suburb)
        • Duration: 45 minutes round trip
        • Equipment: Custom delivery drone

        SORA Assessment: Ground Hazards:
        • People: High (dense population, streets, parks)
        • Infrastructure: High (buildings, power lines, telecom towers)
        • Terrain: Complex (urban canyon effects)
        • Ground Risk Rating: HIGH

        Airborne Hazards:
        • Airspace: Mixed (controlled near airport, Class G elsewhere)
        • Traffic: High (commercial airlines, helicopters, general aviation)
        • Deconfliction: Complex (requires ATC coordination)
        • Airborne Risk Rating: HIGH

        SORA Level: 4โ€“5 (High to extreme risk) Mitigations Required:
        • โœ… Full ReOC + special CASA approval
        • โœ… Advanced safety case (100+ pages)
        • โœ… ATC coordination procedures
        • โœ… Redundant communication systems
        • โœ… Redundant GPS (dual receivers)
        • โœ… Automatic contingency landing capability
        • โœ… Real-time surveillance system
        • โœ… Insurance A$50M+
        • โœ… Advanced crew training (40+ hours)
        • โœ… On-site safety officer monitoring

        Approval Timeline: 120โ€“180 days

        SORA Assessment Mistakes to Avoid

        Common Errors

        • โŒ Underestimating ground risk (claiming "no people" when homes nearby)
        • โŒ Ignoring airspace classification (missing controlled airspace requirements)
        • โŒ Insufficient mitigations (claiming procedures without testing them)
        • โŒ Poor documentation (vague ConOps, insufficient detail)
        • โŒ Inadequate crew training (crew not qualified for procedures)
        • โŒ No contingency planning (no backup if primary system fails)
        • โŒ Weak risk analysis (not following SORA methodology)
        • CASA SORA Assessment Tools

          CASA-Provided Resources

          CASA publishes free resources:
          • SORA guidance documents
          • Risk assessment templates
          • Hazard identification checklists
          • Sample ConOps

          Download from: casa.gov.au (CASR Part 101 guidance section)

          Approved Assessment Tools

          Some consultants provide software:

          • Flyby Technology SORA Tool (A$500โ€“A$2,000)
          • Kroll Risk Assessment Software (A$1,000โ€“A$5,000)
          • Custom assessment (spreadsheet-based) (free)
          • Working with CASA on SORA

            Submission Process

            1. Develop ConOps (internally or with consultant)
            2. Complete SORA assessment (determine risk level)
            3. Submit to CASA (via ReOC application)
            4. CASA review (30โ€“90 days depending on complexity)
            5. CASA feedback (may request clarifications or changes)
            6. Resubmit if needed (address CASA concerns)
            7. CASA approval (operation authorized)

            CASA Approval Outcome Options

            A. Full Approval
            • Operation authorized as proposed
            • No conditions or restrictions

            B. Conditional Approval
            • Operation authorized with conditions
            • Examples: "Maximum 50m distance from buildings," "NOTAM required 24 hours prior"
            • Most approvals are conditional

            C. Rejection + Resubmit Opportunity
            • Operation as proposed unacceptable
            • CASA provides feedback
            • Operator may resubmit with modifications

            D. Rejection
            • Operation fundamentally unsafe
            • No path to approval without major redesign
            • Rare outcome
            • FAQ

              Q: Is SORA required for all drone operations?

              A: No. Exempt operations (e.g., toys, simple recreational use) don't need SORA. Commercial operations require it.

              Q: Can I skip SORA if I have ReOC?

              A: ReOC application includes SORA assessment. So they're linked. ReOC = SORA assessment bundled together.

              Q: Who can perform SORA assessment?

              A: You can (if competent), or hire a consultant. CASA requires accurate assessment, not a specific person.

              Q: What if my SORA assessment is disputed by CASA?

              A: Provide evidence (testing, documentation, expert opinion). If still disputed, CASA may assign assessor; usually results in approval with conditions.

              Q: Does thermal imaging affect SORA level?

              A: Yes. Night operations (thermal) increase airborne risk (collision), typically moving operation from Level 2 to Level 3.

              Q: How often must I update my ConOps?

              A: Annually minimum. Major changes (new location, new equipment, new operation type) require immediate update.

              Q: Can I hire someone to do SORA for me?

              A: Yes. Consultants (A$5,000โ€“A$30,000) can prepare ConOps and SORA assessment. You remain responsible for accuracy.

              Q: What if CASA requests additional mitigations after approval?

              A: Update ConOps and resubmit. Usually approved quickly if changes are reasonable.

              Q: Does MmowW help with SORA assessment?

              A: Yes. MmowW provides SORA templates, hazard checklists, and ConOps guidance. Cost: A$8.50/drone/month.

              Q: How detailed must ground hazard analysis be?

              A: CASA expects: specific people count/density, infrastructure identified by type, terrain characteristics. Vague descriptions will be rejected.

              Q: Can SORA assessment reduce my insurance requirements?

              Key Takeaways

              โœ… SORA assesses operational risk (ground + airborne hazards) โœ… SORA Levels 1โ€“5 determine approval pathway and required mitigations โœ… ConOps (safety case) is mandatory for commercial operations โœ… Most operations are Level 2โ€“3 (relatively straightforward approval) โœ… Level 4โ€“5 operations are rare and require 120+ days approval + A$100,000+ โœ… Accurate hazard identification critical โ€” CASA reviews rigorously โœ… Mitigations must be validated (not just claimed)

              Last Updated: April 2026 | CASA Regulation: CASR Part 101 | Authority: Civil Aviation Safety Authority