NTSB Factual Report

On March 5, 2004, at 2025 mountain standard time, an Airbus Industrie A320-232, N467UA, owned by United Air Lines, Incorporated, and operated as United Airlines Flight 1443, collided during taxi for takeoff with an Airbus Industrie A320-232, N482UA, being operated as TED Flight 831, at the Denver International Airport (DEN), Denver, Colorado. The TED A320 was standing and connected to a tug at the time of the incident. Both airplanes sustained minor wingtip damage. The airline transport certificated captain, airline transport certificated first officer, 4 cabin crew members and 67 passengers on the United A320 were not injured. The airline transport certificated captain, airline transport certificated first officer, 4 cabin crew members and 130 passengers on the TED A320 were not injured. Both airplanes were operating on instrument flight rules flight plans under the provisions of Title 14 CFR Part 121. Flight 1443 was planned to fly from DEN to Phoenix, Arizona. Flight 831 was planned to fly from DEN to Ontario, California. Night visual meteorological conditions prevailed.

In his written statement, the captain on the United A320 said that during their pushback, the TED A320 was being pushed back at an angle from its gate toward their position. The captain said he relayed his concern to the ground crew, but did not receive a clear response. As the TED A320 approached, two persons from their push crew ran out, "apparently to get a better view. Both airplanes were finally stopped in close proximity. We were positioned to the east of our push line, toward the other aircraft." The captain said that he requested that his tug remain in place in case they had to return to the gate for a sick passenger. When it was determined the passenger could fly, they started engines and released the pushback crew. He said the crew disconnected and they received a salute and a release from guidance for a left turn out. The captain said that to their right, the TED A320 was still connected to its tug and one of its ground crew was standing to the left front of the airplane facing aft. "He was looking toward us and holding his right hand overhead, and with his left arm out and slightly raised, indicating the wingtip clearance distance." The captain said, "I taxied slowly forward at idle thrust and eased toward the left. After a short distance, the wingtips collided."

The captain on the United A320 said that communicating with their tug was difficult due to language and non-standard phraseology used by the pushback crew. The captain said clarification was needed and asked for at least two times. The captain said, "The ground communicator had no apparent knowledge of SOP (standard operating procedures) language or response for the pushback procedure."

The first officer on the United A320 said that after the passenger issue was resolved, they started their engines. "Engine start was normal and after my after start flow the captain announced I have a salute and release from guidance, and then taxi clearance." The first officer said both he and the captain looked at a ground crew member standing in front and between the two airplanes, looking at us with wand raised and other arm held out horizontally indicating wing clearance. I called for taxi and we were cleared for a left turn out. With wing man guidance and a visual check I told the captain we were cleared on the right. We started to move and I glanced forward. When I looked back out to the right, the wing walker was gone, and then the wingtips made contact. I had no time to react before impact."

One of the ground crew members on the TED A320 said he was wing walking for the airplane on the first officer's side. Another ground crew member was on the captain's side of the TED A320. The first ground crew member said the other ground crew member stopped the pushback. He said he went around to see what was happening. As he did, the first ground crew member saw the wings of the two airplanes "about 20 to 30 feet apart." The first ground crew member said he looked at the first officer on the United A320 and gave him "the hold sign." He said he then went to the tug operator to discuss the position of the airplane. As he was talking with the tug operator, the United A320 "proceeded to move and clipped the wing."

An examination of the United A320 showed crush damage to the leading edge spoiler of the right wing, just inboard of the winglet. An examination of the TED A320 showed crush and tearing damage to the underside of the left winglet.

The United Airlines pushback procedures for Gates A46 and A48 at the Denver International Airport cited, "The coordination of the pushback must include ... verbal agreement between gate crews ... on which aircraft is being moved first, [and] continual visual observance of the clearance between aircraft ..."

NTSB Probable Cause

the flight crew’s failure to maintain clearance from the other airplane and the ground crews' failure to follow proper pushback procedures. Factors contributing to the incident were the flight crew’s inadequate visual lookout, the other airplane ground crew's confusing visual signals to the flight crew, and the flight crew’s inability to understand the signals being given to them.