Identifying the Factors that Contributed to the Ueberlingen Midair Collision

On the night of July 1, 2002, a Boeing 757 collided with a Tupolev-154 at 35,000 feet, resulting in 71 fatalities. Initially, this accident was immediately blamed on two individuals. First, the pilot of the Tupolev aircraft whose command of the English language was questioned when repeated descent instructions from ATC were not immediately responded to. The second individual was the controller on duty, who was accused of not exercising the abilities needed in order to detect the presence of a conflict between aircraft and resolve them. In this paper, we provide an analysis of the event, highlighting fundamental human and system errors that occurred that night: errors that contributed to the worst midair collision in recent history.