Phoenix Sky Harbor Int'l Airport
Aircraft Accident/Incident Report

Phoenix, Arizona 85034
Friday, October 15, 1999 9:18 MST

On pushback from the gate, the tug driver was positioning the nose wheel on a painted stop mark on the ramp known as the 'T' when the tail struck a walkway between concourses. Company procedures require each tug driver to put the nose wheel on the 'T' during pushback. This procedure had been previously discontinued at this gate due to the construction of the pedestrian walkway that did not allow sufficient clearance. On the morning of the accident, the ramp coordinator advised the ramp 1 supervisor that pushbacks to the 'T' at this gate would resume that morning. The ramp 1 supervisor asked for confirmation due to concerns over adequate clearance, and the instruction was reconfirmed that all gates on ramp 1 would push to the 'T.' No coordination was made with the ground operations safety supervisor. During the accident sequence, ramp control cleared the flight to push to the 'T' and the captain relayed the clearance to the tug driver. The wing walkers were properly positioned. When the aircraft was about 20 feet from the walkway, the right wing walker saw the impending collision and signaled the tug driver to stop. The tug driver said he was focused on correctly positioning the nose wheel on the 'T' and did not see the signal in time to stop the aircraft. About 10 feet before reaching the 'T,' the aircraft's right horizontal stabilizer struck the pedestrian walkway. There is no voice communication capability between the crew chief at the gate, the tug driver, and the wing walkers. The completed walkway had reduced the amount of ramp space available during pushback to substantially less than the length of the airplanes operated by the airline. The 'T' had not been repositioned. The original decision to resume the pushback originated with the ACS project manager but should have been coordinated with the ground operations safety supervisor prior to any operational changes being implemented.

The airline's failure to fully review the obstruction clearances and revise the pushback procedures in an area of the ramp where new construction had impinged on the available ramp space. Also causal was the failure of the tug driver and the wing walkers to maintain adequate communications during the pushback. A factor in the accident was the failure of the airline to follow its own internal decision processes when implementing the procedural change on this ramp.