Army aeromedical crash rates

Background: Safety is a principal concern for everyone in aviation, includi ng those in military and civilian aeromedical programs. The U.S. Army flies thousands of helicopter missions each year, including many aeromedical fli ghts. The comparison between Army general and aeromedical aviation crash da ta provides a benchmark for establishing patterns in aeromedical safety and may be useful for similar programs examining safety profiles. Objectives: To determine the crash rates of Army aeromedical rotary-wing (helicopter) p rograms and compare them with crash rates in Army general aviation. Methods : Retrospective review of safety data from 1987 to 1995. Crashes or mishaps are categorized into three classes: A, B, and C, Class A reflects the most serious mishap and involves loss of life or aircraft destruction, whereas classes B and C represent lesser but still significant mishaps. Crash rates are compared on a year-by-year basis and are reported as events per 100,00 0 night hours. Statistical analysis was performed by the z test with Yates' correction, with significance set at p less than or equal to 0.05, Results : During the study period, 13.31 million total flight hours were recorded, with 741,000 aeromedical hours logged, The mean Army general aviation class A crash rate was 1.86 compared with the aeromedical rate of 2.02. The mean general class A to C crash rate was 7.37 compared with the aeromedical rat e of 7.44. Between 1992 and 1995, there were 3 Sears when the Army aeromedi cal program suffered no class A mishaps. Differences between study groups a re statistically significant, but they are interpreted conservatively given the very low incidence of mishaps in both groups. Both rates are comparabl e with published civilian mishap rates. Conclusions: There is a very low ov erall incidence of crashes in both groups. There may be no practical differ ence between Army general and aeromedical aviation mishap rates. Furthermor e, Army crash rates are comparable with published civilian mishap rates.