GVC Operational Risk Assessment — Questions and Answers
Question 1: In a drone operational risk assessment, what is meant by 'Ground Risk Class' (GRC)?
- A measure of the expected severity of harm to people on the ground if the drone crashes (Correct answer)
- The classification of the ground surface type below the flight path
- The operator's insurance coverage tier for ground incidents
- A CAA certificate required before flying over populated areas
Correct answer: A measure of the expected severity of harm to people on the ground if the drone crashes
Ground Risk Class (GRC) is used in the SORA methodology to quantify the risk to people on the ground in the event of an uncontrolled landing or crash. It considers factors such as drone size, population density below the flight path, and whether the area is controlled (e.g., a cordoned-off site).
Question 2: What is an 'operational volume' in the context of a SORA risk assessment?
- The volume of airspace used during normal operations, defined by lateral and vertical boundaries including buffers (Correct answer)
- The physical volume of the drone including its rotors
- The maximum payload weight the drone can carry safely
- The area of ground below the planned flight path
Correct answer: The volume of airspace used during normal operations, defined by lateral and vertical boundaries including buffers
The operational volume is the three-dimensional airspace block within which the drone conducts its normal mission, including buffers for navigation uncertainty and contingency manoeuvres. It forms the basis for assessing both ground and air risk in the SORA process.
Question 3: What is a 'contingency volume' in SORA and why is it important?
- The additional airspace beyond the operational volume into which the drone may fly to execute a contingency procedure, such as an emergency landing (Correct answer)
- The backup battery volume required by regulations
- The volume of space reserved for ground observers
- An additional airspace block that must always remain empty
Correct answer: The additional airspace beyond the operational volume into which the drone may fly to execute a contingency procedure, such as an emergency landing
The contingency volume surrounds the operational volume and accounts for the space needed if the pilot must take emergency action — such as breaking off the mission and landing quickly. Ensuring there are no conflicting aircraft or hazards in the contingency volume is essential to safe operations.
Question 4: How does population density affect the Ground Risk Class in a SORA assessment?
- Higher population density increases the GRC because more people could be harmed if the drone crashes (Correct answer)
- Population density has no effect — only drone size matters for GRC
- Higher population density decreases GRC because urban areas have better emergency services
- GRC only applies in rural areas where ATC services are unavailable
Correct answer: Higher population density increases the GRC because more people could be harmed if the drone crashes
SORA considers population density as a primary factor in GRC. Flying over densely populated urban areas creates higher ground risk than flying over uninhabited rural land, because the probability of a person being struck in the event of a crash is significantly greater.
Question 5: What is a 'mitigating measure' in a drone operational risk assessment, and give an example?
- An action or technical measure that reduces the likelihood or severity of an identified risk, e.g., cordoning off the area below the flight path to exclude uninvolved persons (Correct answer)
- A financial guarantee paid to the CAA before operations begin
- A NOTAM filed 24 hours before flight
- An additional qualification held by the remote pilot
Correct answer: An action or technical measure that reduces the likelihood or severity of an identified risk, e.g., cordoning off the area below the flight path to exclude uninvolved persons
Mitigating measures reduce either the probability of a hazard occurring or its consequence if it does. Establishing a controlled ground area (cordon) below the flight path is a common mitigation that reduces population exposure and can lower the effective GRC, enabling operations that would otherwise exceed open category limits.
Question 6: What is the purpose of defining 'critical areas' in a pre-flight operational risk assessment?
- To identify specific locations where failure would have the most severe consequences, requiring additional mitigation measures (Correct answer)
- To mark areas where the drone's GPS signal is strongest
- To designate zones where the ground crew must stand during flight
- To identify areas where return-to-home should be activated automatically
Correct answer: To identify specific locations where failure would have the most severe consequences, requiring additional mitigation measures
Critical areas are locations within or adjacent to the operational area where a drone failure would have the most serious consequences — such as directly over a road, near a hospital, or above densely occupied buildings. Identifying these areas allows operators to plan routes that avoid or minimise exposure to the highest-consequence locations.
GVC Operational Risk Assessment
In a drone operational risk assessment, what is meant by 'Ground Risk Class' (GRC)?