Human Factors and Their Impact on Situational Awareness in HEMS and HSAR Personnel: Liveware-Centered Perspectives from Norwegian Air Rescue and Medical Operations

Abstract

Loss of or absent situational awareness has previously been found to be a frequent cause in aviation accidents classified as Controlled Flight Into Terrain (CFIT). The research literature indicate a gap in the studies of human factors and situational awareness in helicopters, specifically in Helicopter Emergency Medical Services (HEMS) and Helicopter Search and Rescue (HSAR). This formed the incentive for this thesis.

This thesis explores operators in the sharp end of HEMS and HSAR missions. It specifically explores how human factors influence their ability to establish and maintain situational awareness on missions, and how safety barriers support and protect them from situational awareness failure. Three guiding research questions were developed to fully answer the main research question. 9 semi-structured interviews with informants from both services in Norway were conducted, using an interview guide with 24 premade questions. The theoretical framework primarily applies Endsley’s (1995) three-level model of situational awareness; SHELL (Software, Hardware, Liveware, Liveware), and different perspectives of safety barriers and human error to understand, describe, explain and discuss the findings.

This study concludes the findings based on the main research question: How do human factors influence the ability of operators to establish and maintain situational awareness, and how can safety barriers mitigate the negative effects of human factors to prevent situational awareness failure in helicopter rescue and medical missions? Human factors like stress, fatigue, communication issues, distractions, pressure, complacency, cognitive workload and weather conditions, including low visibility, have been found to significantly influence HEMS and HSAR operator’s cognitive performance, workload management, communication and decision-making, being threats to their perception, comprehension and projection abilities during missions. Hard safety barriers like TAWS, TCAS, autopilot, auto-hover and FDM, along with soft safety barriers like SOP’s, checklists, briefings, standardized communication, training and exercise, knowledge and experience play essential roles in supporting the operators. However, it was also found that automated systems may induce complacency if over relied upon, and SOP’s might degrade knowledge-based solutions if they are too rigid. These safety barriers mitigate the negative effects of human factors which allows operators to maintain perception of the environment, also reducing cognitive workload, and improving coordination and decision-making – thereby protecting the operators from situational awareness failure triggered by human factors.