DEN04IA050

NTSB incident investigation · Airbus Industrie A320-232 · Denver, CO · March 6, 2004

Incident · No injuriesIncident investigationFinal report
Date
March 5, 2004, 20:25 local (Mar 6, 2004, 03:25 UTC)
Place
Denver, CO
Injuries
209 uninjured
Phase of flight
Taxi
Aircraft
N467UAAirbus Industrie A320-232N482UAAirbus Industrie A320-232
Weather
Visual (VMC) · Night
Status
Completed · report October 28, 2004
Report
Approved by Office Director
Parties
Federal Aviation Administration, United Airlines
Case key
58874

From the NTSB’s public API. By law, NTSB reports can’t be used as evidence in lawsuits over the incident.

On this page

Probable cause

the failure of the other flight crew to maintain clearance from the airplane and the ground crews failure to follow proper pushback procedures.

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.

Sequence of events

NTSB’s coding before 2008: each occurrence and phase of flight, and the causes and factors under it. The codes are defined in NTSB’s coding manual.

On ground/water collision with objectTaxi - to takeoff
Clearance - not maintainedFlightcrewCause
Visual lookout - inadequateFlightcrewFactor
Procedures/directives - improperGround personnelCause
Communications - confusingGround personnelFactor
Communications - not understoodFlightcrewFactor
On ground/water collision with objectStanding
Clearance - not maintainedFlightcrew of other aircraftCause
Procedures/directives - improperGround personnelCause

Analysis

The captain on the United A320 said that during their pushback, a 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 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 causing minor damage to both airplanes. The United 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. 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 of the TED A320. 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 ..."

The captain on the United A320 said that during their pushback, a 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 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 causing minor damage to both airplanes. The United 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. 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 of the TED A320. 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 ..."

Factual narrative

See factual narrative DEN04IA050A.

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 ..."

Aircraft · 2

Registration
N467UA
Reported as
Airbus Industrie A320-232
Category
Airplane
Serial number
1359
Airframe hours
10,929
Engines
International Aero Engines V2500, 25,000 lbs thrust, turbo jetInternational Aero Engines V2500, 25,000 lbs thrust, turbo jet
Damage
Minor damage
Flight
Part 121
Registered owner
United Air Lines, Incorporated
Airworthiness certificate
Standard, Transport
Last inspection
Continuous airworthiness · April 9, 2002 · 6,554 hours before
Departed
DEN · Denver, CO
Destination
PHX · Phoenix, AZ
Flight plan
IFR
Airport
DEN · Denver Intl

Matched to the registry by N-number and the event date; the registry’s history has gaps, so older matches can be wrong. Compare the reported make and model.

Registration
N482UA
Reported as
Airbus Industrie A320-232
Category
Airplane
Serial number
1584
Engines
International Aero Engines V2500, 25,000 lbs thrust, turbo jetInternational Aero Engines V2500, 25,000 lbs thrust, turbo jet
Damage
Minor damage
Flight
Part 121
Registered owner
Wells Fargo Bank Northwest NA Trust
Airworthiness certificate
Standard, Transport
Last inspection
Continuous airworthiness · May 15, 2002
Departed
DEN · Denver, CO
Destination
ONT · Ontario, CA
Flight plan
IFR
Airport
DEN · Denver Intl

Matched to the registry by N-number and the event date; the registry’s history has gaps, so older matches can be wrong. Compare the reported make and model.

Flight crew · 4

As NTSB recorded them. NTSB leaves out names.

Role
Pilot, aircraft N467UA
Age
54
Injuries
None
Certificates
Flight instructor, Airline transport
Airplane ratings
Single-engine sea, Multi-engine land, Single-engine land
Instrument ratings
Airplane
Medical
Class 1, Valid Medical--no waivers/lim.
Last flight review
September 2, 2002
Seat
Left
Flight hours
5,937 total · 2,000 in this make and model · 4,063 as pilot in command · 206 in the last 90 days · 85 in the last 30 days · 4 in the last 24 hours
Role
Co-pilot, aircraft N467UA
Age
38
Injuries
None
Certificates
Airline transport, Flight instructor
Airplane ratings
Single-engine land, Multi-engine land
Instrument ratings
Airplane
Medical
Class 1, Valid Medical--no waivers/lim.
Last flight review
November 1, 2002
Seat
Right
Flight hours
3,683 total · 1,192 in this make and model · 197 in the last 90 days · 56 in the last 30 days · 4 in the last 24 hours
Role
Pilot, aircraft N482UA
Age
49
Injuries
None
Certificate
Airline transport
Airplane ratings
Multi-engine land, Single-engine land
Instrument ratings
Airplane
Medical
Class 1, Valid Medical--no waivers/lim.
Last flight review
September 1, 2003
Seat
Left
Flight hours
5,814 total · 1,806 in this make and model
Role
Co-pilot, aircraft N482UA
Age
39
Injuries
None
Certificate
Airline transport
Airplane ratings
Single-engine land, Multi-engine land
Instrument ratings
Airplane
Medical
Class 1, Valid Medical--no waivers/lim.
Last flight review
January 1, 2003
Seat
Right
Flight hours
4,401 total · 1,490 in this make and model

Weather

Conditions
Visual (VMC) · Night
Wind
200° at 11 knots
Visibility
2 statute miles
Lowest ceiling
2,600 ft broken
Temperature
30 °F, dew point 28 °F
Altimeter
29.62 inHg
Observed at
DEN, 1 nm away