A Network-based Simulation Model for Helicopter Rescue Time Estimation in the Canadian Arctic
Date
2025-08-07
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Abstract
Helicopter-based Search and Rescue (SAR) operations in Northern Canada are essential for assisting individuals in distress across both land and marine environments under extreme Arctic conditions. This thesis introduces a practical and adaptable approach to estimate total response time, encompassing the transit time (time to reach the incident location), the on-board time (time required to hoist individuals into the helicopter), and the rescue time (time to transport them to a safe destination). This estimation is supported by a set of integrated models that reflect key operational and environmental conditions. Among these, the HeliSAR Pathfinder (Helicopter Search and Rescue Path Finder) model plays a central role in identifying viable mission routes. The HeliSAR Pathfinder Model generates feasible helicopter rescue routes from operational bases to potential incident locations, accounting for range limitations, fuel capacity, and available refueling stations across the Arctic. These paths form the structural foundation for modeling time-dependent mission activities. Next, the Royal Canadian Armed Forces Helicopter Environmental Operability (RHEO) Model is applied to assess how environmental conditions affect helicopter performance, categorizing weather scenarios as ‘Favorable’, ‘Unfavorable’, or ‘No-Go’. These classifications influence which routes remain viable and how long missions may be delayed or extended due to adverse weather conditions. Building on the route and operability inputs resulting from the HeliSAR Pathfinder and RHEO models, the Helicopter SAR Simulation Model (HESARSI) uses a Discrete Event Simulation (DES) framework to simulate the full mission sequence (including e.g., helicopter takeoff, refueling, search, and rescue). To reflect operational uncertainty, Monte Carlo Simulation (MCS) introduces randomness into key variables such as weather conditions, takeoff readiness, and hoist time for Persons in Distress (PID), producing a distribution of potential transit and rescue durations under varying scenarios. This research also explores the potential benefits of establishing a new SAR helicopter base in Iqaluit, evaluating its impact on transit times across various communities in Northern Canada. The analysis includes an operational accessibility study to determine which incident locations can realistically be reached by helicopter, considering constraints such as flight range, refueling logistics, and environmental conditions. The study further examines how factors like incident distance, seasonal weather variability, refueling requirements, and the number of Persons in Distress (PID) affect the response times. Results reveal significant spatial and seasonal disparities across all response time components. For instance, rescue times in northernmost zones often exceed 27 hours during winter months, whereas southern regions may achieve rescue times of under 15 hours in summer. Overall, this work provides actionable insights for SAR planners and emergency management authorities, enabling more informed strategic decisions to improve safety, responsiveness, and resilience in Canada’s remote Arctic communities and coastal areas.
Description
This thesis developed and implemented a simulation-based modeling framework to evaluate helicopter Search and Rescue (SAR) response times in the Canadian Arctic, addressing a range of operational constraints including fuel capacity, weather conditions, route selection, and infrastructure limitations. The framework was structured to answer eight core research questions. First, in terms of estimating the time required for a helicopter to reach an incident location (Transit Time or TT), results demonstrated significant spatial and seasonal variation, with some zones particularly in the high Arctic experiencing third-quartile TT values exceeding 25–30 hours. This was attributed to long travel distances, harsh winter weather, and limited refueling opportunities. Second, On-board Time (OT), which adds the time spent hoisting individuals onto the helicopter, was consistently greater than TT and ranged from 1 to 7.5 hours above the base travel time in the PID = 12 scenario. The difference was more pronounced under poor weather conditions, reflecting the combined effects of visibility, wind, and icing delays. Third, Rescue Time (RT), which extends beyond OT to include transportation to the nearest safe location, further emphasized geographic and environmental constraints, with total rescue times occasionally surpassing 30 hours. Fourth, the introduction of Iqaluit as a fourth SAR base significantly reduced TT and RT for several underserved eastern Arctic communities, in some cases by 6 to 10 hours, demonstrating the value of infrastructure expansion in high-risk regions. Fifth, the inclusion of strategically selected alternative routes provided routing resilience under changing weather conditions. While not always faster than the shortest path, these routes offered meaningful options for mitigating unfavorable weather effects and avoiding inaccessible waypoints. Sixth, accessibility analysis showed that many northern incident locations are unreachable without mid-route refueling, and even with refueling stations included, certain zones remained inaccessible under persistent No-Go weather conditions, emphasizing gaps in current coverage. Seventh, the environmental operability model (RHEO) revealed that weather is the most critical factor influencing aerial SAR feasibility. Favorable conditions supported maximum speed and efficiency, while unfavorable conditions reduced speed and increased fuel consumption. No-Go conditions triggered mandatory delays, which the model handled by checking weather each hour until operability was restored. These delays were then added to TT, OT, and RT estimates. Eighth, a sensitivity analysis confirmed the robustness of the results under varying assumptions, and expert interviews and validation provided additional confidence in the model’s structure and logic. Overall, this study highlights the complexity of Arctic SAR planning and the value of simulation-based tools for assessing response time under realistic operating conditions. The use of percentile-based performance metrics, particularly the 75th percentile, allowed for conservative planning. Furthermore, integrating this framework with marine-based METR-VT models could yield a more complete picture of multi-modal SAR capabilities. While some limitations remain including weather data resolution and assumptions around search duration, the thesis lays a strong foundation for future research and policy development aimed at enhancing SAR readiness in Canada’s northern and polar regions.
Keywords
Search and Rescue, HeliSAR-Pathfinder, Maximum Expected Time of Rescue (METR), Helicopter Operations, Northern Canada, Inuit Nunangat, Discrete Event Simulation, Monte Carlo Simulation, Emergency Response