Akira Nakamura1. 1. Information Administrative Division, Aero Safety Service Group, Japan Air Self-Defense Force, Tokyo, Japan. an4f2006@yahoo.co.jp
Abstract
BACKGROUND: Ejection injuries and fatalities are a problem around the world. However, the definitions of injury types in past studies have been idiosyncratic, and it has been difficult to compare studies across national air forces and aircraft types. This study determined factors that contribute to injury or fatality in ejections in the Japan Air Self Defense Force (JASDF). METHODS: The records for all JASDF ejections for the period 1956-2004 were analyzed to determine the relationships between types of injuries and ejection characteristics. RESULTS: There were 140 cases, of which 32 (22.9%) induced fatal injuries, 13 (9.3%) major injuries, and 95 (67.9%) no injuries. This fatality rate of nearly 23% is the highest found in similar studies. The most significant reason for fatality was the delay in the decision to eject, accounting for approximately 40%. This tendency to delay the decision to eject was observed across all of the time periods studied. Fuel exhaustion due to changeable weather was cited as a reason for ejecting at a higher rate than in other countries. CONCLUSIONS: Delay in the decision to eject was the most significant problem affecting ejection survival in Japan and was constant over time.
BACKGROUND: Ejection injuries and fatalities are a problem around the world. However, the definitions of injury types in past studies have been idiosyncratic, and it has been difficult to compare studies across national air forces and aircraft types. This study determined factors that contribute to injury or fatality in ejections in the Japan Air Self Defense Force (JASDF). METHODS: The records for all JASDF ejections for the period 1956-2004 were analyzed to determine the relationships between types of injuries and ejection characteristics. RESULTS: There were 140 cases, of which 32 (22.9%) induced fatal injuries, 13 (9.3%) major injuries, and 95 (67.9%) no injuries. This fatality rate of nearly 23% is the highest found in similar studies. The most significant reason for fatality was the delay in the decision to eject, accounting for approximately 40%. This tendency to delay the decision to eject was observed across all of the time periods studied. Fuel exhaustion due to changeable weather was cited as a reason for ejecting at a higher rate than in other countries. CONCLUSIONS: Delay in the decision to eject was the most significant problem affecting ejection survival in Japan and was constant over time.