Northwest Airlines McDonnell Douglas DC-9-51 accident

An airline employee was attempting to connect a tractor tug to a towbar attached to the nose gear of an airliner in preparation for pushback. The airliner was parked at the gate, and was boarding passengers for the Title 14, CFR Part 121 flight at the time of the mishap. Another airline employee on the ramp saw the tug driver maneuver the tug toward the towbar, heard a loud noise, and saw the towbar buckle and "go into the air." The witness went to the nose of the airplane, and saw the tug "going directly into the aircraft." The witness did not notice whether the airline employee was sitting or standing in the tug, or whether she was looking forward or backward. The tug struck the radome of the airplane, and the airline employee who was driving the tug was fatally injured after being trapped between the tug and the airplane. The airline's tug had an open-air type cab. Documentation of the tug and towbar revealed that the towbar was not engaged with the tug and had been pushed (jammed) into the tug as the tug moved toward the airplane. The tug was inspected and tested after the accident and no anomalies were noted with its operational capabilities. Additionally, the tug had been operated several times earlier on the day of the accident with no problems noted. The ramp conditions at the time of the accident were adequately illuminated and dry. Passengers were still boarding at the time of the accident, and no urgency existed for the pushback. The airline required a recurring practical evaluation of ground operational safety every three years. An examination of training records, and interviews from airline personnel, revealed that the airline employee who was killed had not received pushback training since 1992, nor was she formally qualified or authorized to conduct pushback operations at the time of the accident. On the day of the accident, the airline employee was assigned bag room duties. The investigation could not determine how frequently or recently the airline employee may have operated the pushback tractor, or how familiar she may have been with its controls. Ground operations staffing at the time of the accident included four employees, which was at a level consistent with the airlines' station staffing model range. The investigation revealed that the staffing level had no direct bearing on this accident. As a result of the accident, the airline used a pushback tug that was equipped with a protective enclosure over the driver cab, and the airline issued additional guidance in its ground operations manual regarding pushback operations, to include requiring an additional person to assist in connecting the towbar to the tug.

( This case was modified on October 5, 2006 )

Verbatim NTSB analysis and probable cause from the NTSB dataset