Boeing 737-832 N397DA and Boeing 757-351 N585NW accident near Seattle, Washington

Probable cause

The failure of the tug operator and wing walker of this airplane to maintain clearance with the other aircraft during the pushback process in dark night. Also causal was the ramp controller's misinterpretation of the other airplane's gate location and her improper clearance for both airplanes to simultaneously push back from nearly opposing gates.

The failure of the tug operator and wing walker of the other airplane to maintain clearance with this aircraft during the pushback process in dark night. Also causal was the ramp controller's misinterpretation of the other airplane's gate location and her improper clearance for both airplanes to simultaneously push back from nearly opposing gates.

NTSB analysis

A Boeing 757-351 and a Boeing 737-832 were substantially damaged when the tails of both airplanes collided during the pushback process from two opposing terminal gates during night visual meteorological conditions. The flight crew and ground crew of the Boeing 737-832 reported that they had stopped, were in a static position, and in the final stages of disconnecting the tug when the collision occurred. The ground crew of the Boeing 757-351 reported that they never observed the Boeing 737-832 during their pushback process. Review of recorded communications tapes between the flight crews of both aircraft and the ramp controller revealed that the Boeing 757-351 was cleared to be pushed into the alleyway with its tail to the south. About 9 seconds later, the Boeing 737-832 was cleared for pushback into the alleyway with its tail to the north. The recorded communications tapes revealed that the ramp controller did not advise either aircraft of the opposing pushback operations. The controller stated that she thought that the Boeing 737-832 was requesting to push back from a different gate than they had requested; however, the recorded communications tapes clearly have flight crew of the Boeing 737 stating their correct gate in their initial call for a pushback clearance.

Text from the NTSB. Open the NTSB docket for WPR09FA068 for the full record.