Injury and Fatality Patterns in US Navy Rotary Wing Mishaps A Descriptive Review of Class A and B Mishaps From 1985 to 2005

摘要

A recent report of US general aviation accidents by the National Transportation Safety Board (NTSB) reveals that helicopters have the highest accident rates and fatality rates among powered, non-amateur built aircraft. The US Navy also reports greater rates for helicopter accidents. These statistics reflect aircraft mishap rates but do not evaluate the human toll. This study describes aircrew and passenger injury patterns associated with US Navy (USN) and US Marine Corps (USMC) helicopter mishaps for fiscal year 1985 through 2005. The objective is to identify any relationship between injury outcomes with crew position, mission type, phase of flight, seat design, helmet use, and restraint configuration. Injuries were divided into four categories of severity and seven anatomical location categories. Descriptive statistics were used to illustrate associations of these categories with crew position, mission, phase of flight, seat design, and airframe. Rotary wing mishaps in this USN/USMC dataset were associated with eight aircraft categories and 31 different models. Results of this study found that mishap rates in each category varied widely from 1.18 to 6.63 mishaps per 100,000 flying hours. Mishaps were also divided into four phases of flight. Proportions of fatalities were found to be statistically higher in the cruise phase when compared to other phases of flight (p < 0.001). Descriptive statistics also revealed that the proportion of personnel exposed to mishaps who were uninjured was the greatest in the trainer aircraft and those aircraft with larger crew compartments. The most common injury location was the head for both pilots and those personnel in the crew compartment. Crew position comparisons also found that pilots were statistically more likely to walk away from a mishap uninjured than non-pilots (p < 0.002). These results were not due to differences in spinal injury. Spinal injuries were found to be more common in pilots than non-pilots. These data were also divided into two decades of data; mishaps occurring in FY 85 - 94 and those occurring in FY 95 - 05. The USN experienced a period of significantly fewer fatalities and non-fatal injuries during the second decade. This reduction in fatalities and injuries was present in all eight airframe categories. The variable that appears to be the most associated with this decrease in fatality rates is regarding over-water missions. The numbers of those personnel who died as a result of drowning or becoming lost at sea dropped from 119 in the first decade to 14 in the second decade.