Safety of helicopter aeromedical transport in Australia: a retrospective study

Objectives: To determine the accident rate for Australian helicopter emergency medical services (HEMS) per 100 000 flying hours and to determine the patient mortality risk per mission from a HEMS accident. Method: Retrospective observational study of Australian HEMS flying hours and accidents from 1992-2002. Results: The calculated accident rate for Australian HEMS is 4.38 per 100 000 flying hours. One patient died as a direct result of helicopter accident in 50 164 missions. Overall, one accident occurred every 16721 missions. Conclusions: The overall Australian HEMS accident rate is similar to that reported from other countries, with all accidents occurring in Queensland community HEMS. Helicopters flown at night under Visual Flight Rules (VFR) appear to represent a high-risk subgroup. HEMS flights do not appear to present significant mortality risk to patients being transported.