The threat collision avoidance system prompted evasive action when a Republic Airways Bombardier CRJ-200 out of Greensboro, N.C., and Skyways Airlines Dornier 328 were allowed to get within 1.3 miles and 600 feet vertically last Tuesday. The flight was operated by Republic Airways for US Airways, but, as with many flights, was also listed as a United Express flight. It had 31 passengers on board, while the Skyways aircraft carried 24.
The incident was the third Class B incident at the Chicago Center since October 1. The two airliners were at 25,000 feet over Indiana. The FAA indicated the error occurred when a veteran controller at Chicago Center dropped the regional aircraft from the radar screen after acknowledging en route to Chicago. The Midwest aircraft was en route from Milwaukee to Dayton when the controller, just coming off of break, allowed it to descend in conflict with the Republic aircraft. The FAA classified the error as B, the third since October 1 at the facility compared to only one during the previous 12 months. The National Air Traffic Controller Association blamed the error on over-worked staffers and understaffing.