Date of Award

Spring 2014

Access Type

Thesis - Open Access

Degree Name

Master of Science in Human Factors & Systems


Human Factors and Systems

Committee Chair

Dr. Albert Boquet, Ph.D.

First Committee Member

Dr. Scott Shappell, Ph.D.

Second Committee Member

Dr. Douglas Wiegmann, Ph.D.


In 1972, the first hospital based civilian helicopter emergency medical service (HEMS) in the United States began operations. While the use of helicopters to transport medical casualties started decades previously, St. Anthony Flight for Life represented the start of an industry that would grow rapidly in the years to follow, both in the US and around the world (Flight for Life Colorado, n.d.).

Helicopters provide a valuable contribution to the field of medicine. They are faster than ground-based transportation and able to reach areas considered otherwise remote or impassible. They are highly manoeuvrable, unhindered by traffic, and can land in confined spaces. Further advancements, such as the use of advanced life support equipment and flight medical personnel have further improved patient outcomes.

After a decade of growth, a disturbing trend emerged in the air ambulance sector. In the early 1980s, the National Transportation Safety Board (NTSB) observed a marked rise in aviation accidents involving ambulance helicopters. Since then it has been observed that there are a disproportionate number of accidents in HEMS flying compared to other types of flying, including fixed-wing EMS. This phenomenon has been the subject of numerous articles, government reports, and news stories (e.g. NTSB, 1988; Harris, 1994; Wright, 2004; Veilette, 2005; and Negroni, 2009).

By its nature, HEMS operations pose more risks than other types of flying. Unscheduled flights into unfamiliar areas and semi-prepared landing surfaces ostensibly increase the chance of an accident or incident. However, examination of HEMS operations in other countries show that the risk is more pronounced in the US than other countries (Table 1). The US had an accident rate in 2000-09 that was both higher than other countries and the previous decade. It also has the highest fatal accident rate, considering that the Australian rate in 2000-09 was the result of a single HEMS crash in 2003.

Included in

Aviation Commons