INTRODUCTION: Loss of control (LOC) accounts for approximately 40% of fatal accidents in general aviation and roughly half of all aviation fatalities. Within Helicopter Emergency Medical Services (HEMS), LOC is an increasingly pressing issue contributing to fatal accidents despite new rulings by the FAA in 2014 intended to improve safety in HEMS operations. This analysis aims to explore the causal factors which contribute to LOC within HEMS.

METHODS: Helicopter Emergency Medical Service accidents occurring between the years 2014-2019 were pulled from the National Transportation Safety Board (NTSB) accident database. Inclusion of FAR Part 91 and Part 135 accident flights resulted in a total of 26 accidents. Causal factors contributing to each accident were then coded using the Human Factors Analysis and Classification System (HFACS). Analyses to obtain frequencies were completed using IBM SPSS.

RESULTS: Of the 26 accidents that occurred between 2014-2019, a total of 17, or 65.4% were associated with LOC. Of these LOC accidents, 54.5% were preceded by inadvertent flight into IMC and were associated with skill based errors (47%). Finally, over half of these accidents (58.8%) resulted in at least one fatality of those on board.

DISCUSSION: Despite new rulings implemented by the FAA, HEMS operations continue to struggle with managing the risk associated with providing emergency and other medical transport for patients. Like other aviation platforms, LOC is a persistent threat to both crew and patients. Preliminary results of an HFACS analysis indicate that skill based errors are the largest contributors to these accidents, prompting further examination of the factors contributing to these errors. It is also worth noting that of the accidents where LOC occurred, over 50% of these involved at least one fatality. Further analysis should focus on the role of current training practices and operational guidelines within HEMS to determine potential strategies for mitigating risks associated with loss of control.

Albert Boquet

Affiliation

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Taking Control: An HFACS Analysis of Loss of Control in Helicopter EMS Flights