Scenario-Based Helicopter Flight Simulation of Accident-Prone Vortex Ring State (VRS) Encounters

From 2008 to 2021, 48 helicopter accidents have involved Vortex Ring State (VRS) encounters in the United States. For dangerous situations such as VRS encounters and recoveries, Scenario-Based Training (SBT) in flight simulators could supplement flight training, allowing pilots to practice in a safe environment. In this study, we created and tested a proof of concept for scenario-based training in flight simulators, dedicated to VRS-related accident prevention. The goal is to evaluate pilots' awareness, avoidance, detection, and recovery skills during VRS-inducing scenarios. Moreover, this study intends to provide a holistic analysis of VRS encounters and recoveries by examining the situations and factors leading to VRS-related crashes, and to lay out the pilot's decision-making process during the event. For that purpose, a comprehensive set of scenarios was developed based on an analysis of VRS-related accidents from the National Transportation Safety Board (NTSB) database. Overall, the scenarios successfully triggered VRS encounters as well as avoidance actions, providing insight into pilots' behavior in and around VRS conditions.