The sensitivity and specificity of control surface injuries in aircraft accident fatalities

Among the important determinations that aircraft crash investigators try to make is which occupant of an aircraft was attempting to control the aircraft at the time of the crash. The presence or absence of certain injuries of the extremities is used to help make this determination. These "control surface injuries" reportedly occur when crash forces are applied to a pilot's hands and feet through the aircraft's controls. We sought to clarify the significance of these injuries and the frequency with which their presence indicates that the decedent was the person that might have been trying to control the aircraft, questions that are frequently asked of the examining pathologist. We studied sequential fatalities of airplane and helicopter crashes in which autopsies were performed by the Office of the Armed Forces Medical Examiner, excluding those that were known to have been incapacitated before the crash and those that were known to have attempted to escape from the aircraft, collecting 100 "qualified" crash decedents. The incidence of control surface injuries was determined for both pilots and passengers. The sensitivity and specificity of control surface injuries were calculated by classifying the decedents into a 4-cell diagnostic matrix. The positive and negative predictive values for control surface injuries were also calculated. Injuries that met the published definitions of control surface injuries had high incidences in passengers, as well as pilots, giving the term control surface injury a diagnostically unacceptable sensitivity and specificity for indicating "a pilot attempting to control an aircraft." We offer caveats and refinements to the definition of these injuries that help to increase the sensitivity and specificity of this term.