PHOENIX, AZ, USA
N627AW
Airbus Industrie A-320-231
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.
On October 15, 1999, at 0918 hours mountain standard time, America West Flight 2433, an Airbus A320-231, N627AW, collided with a pedestrian walkway during pushback in Phoenix, Arizona. The aircraft sustained substantial damage; however, none of the 89 passengers nor the 5 crewmembers were injured. The aircraft was being operated by America West Airlines, Inc., as a scheduled domestic passenger flight under 14 CFR Part 121 when the accident occurred. The airplane was originating as a nonstop flight to Tucson, Arizona. Visual meteorological conditions prevailed at the time and an IFR flight plan was filed. At each gate, America West has a mark painted on the ramp called the "T." This "T" marking is the target point for each tug driver to place the nose wheel during pushback operations. The captain reported that he was at gate A-2 when he received a clearance from ramp control that he was to push to the "T" and to advise when ready to taxi. The captain read the clearance to the tug driver over the intercom. The tug driver read back the clearance and began the pushback about 40 seconds later. Approximately 10 feet before reaching the "T," the aircraft's right horizontal stabilizer struck the pedestrian walkway that connects concourse A to concourse N-1. The tug driver then reported to the captain that, "I may have hit something." The captain made an announcement to the cabin about the nature of the problem and then received permission from ground safety supervisors to pull back to gate A-2. The first officer said he noted the pushback time as 0917 but was not listening to the captain or tug driver as they pushed back. According to statements from America West's new terminal project manager and the ramp control tower manager, during a 0845 conference call, the ramp coordinator advised the ramp 1 supervisor and team leads that pushbacks to the "T" at gate A-2 would resume as of that morning. This procedure had been previously discontinued due to the construction of the new pedestrian walkway between concourses A and N-1 that did not allow sufficient clearance for the pushback. The ramp 1 supervisor asked the ramp coordinator in the tower, as well as the A-2 team lead, for confirmation due to her concern over clearance between the airplanes and baggage carts and construction equipment that were in the vicinity. The tower coordinator and board agent both reconfirmed that all gates on ramp 1 would push to the "T". On the America West ramp, there is no voice communication capability between the crew chief at the gate, the tug driver, and the wing walkers. According to statements of the involved ground personnel and nearby witnesses, the wing walkers were positioned in accordance with company procedures during the pushback. When the aircraft was about 20 to 25 feet from the walkway, the right wing walker signaled the tug driver to stop the push. 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. Safety Board investigators examined the ramp area and found that the completed walkway structure between the concourses had reduced the amount of ramp space to 94 feet 4 inches from the "T" to the walkway; the A321 airplane is 146 feet long from nose to tail. According to the company's internal report on the event, the decision to resume the pushback to the "T" originated with the ACS project manager but should have been coordinated with 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.
Source: NTSB Aviation Accident Database
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