Spatial disorientation mishap trends in the U.S. Air force 1993-2013.

Background: Spatial disorientation is a significant factor in a large percentage of military Class A aviation mishaps. While previous studies have analyzed accident statistics, they often suffer from methodological flaws, which lead to questionable conclusions.

Methods: The current study relied upon the Air Force Safety Automated System to document U.S. Air Force Class A mishap investigations during the past 21 yr. Human Factors Analysis and Classification System codes were used to determine mishaps involving pilot spatial disorientation. The data were combined with data from the Reliability and Maintainability Information System to determine the accident rate per flight hour.

Results: There were 72 spatial disorientation (SD) mishaps analyzed, resulting in loss of 101 lives and 65 aircraft since fiscal year (FY) 1993 for a total monetary cost of 2.32 billion. Class A mishaps involving spatial disorientation had a higher rate as a function of hours flown for helicopter and fighter/attack fixed wing aircraft than other aircraft. Additionally, mishap rates for F-16 fighter/attack aircraft were marginally larger than for other fighter/attack aircraft. Although SD mishaps at night had similar mishap rates to daytime SD mishaps when adjusted by flight hours, SD mishaps account for a larger percent of Class A mishaps during the night than during the day.

Discussion: SD mishaps were analyzed in terms of Class A mishaps per million flight hours. Results indicate that future SD research should be focused on fighter/attack and helicopter platforms. Updates to the Air Force safety center database are recommended.