LAX00LA015

NTSB accident investigation · Airbus Industrie A-320-231 · Phoenix, AZ · October 15, 1999

Accident · No injuriesLimited investigationFinal report
Date
October 15, 1999, 09:18 local (16:18 UTC)
Place
Phoenix, AZ
Injuries
94 uninjured
Damage
Substantial damage
Phase of flight
Pushback/towing
Aircraft
N627AWAirbus Industrie A-320-231
Weather
Visual (VMC) · Day
Status
Completed · report May 17, 2001
Report
Approved by Office Director
FAA report
19991015043609A
Case key
47626

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

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Probable cause

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.

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 - pushback/tow
Object - hangar/airport building
Airport facilities,ramp facilities - congested
Clearance - inadequate
Unsafe/hazardous condition - not identifiedCompany/operator managementCause
Procedures/directives - not verifiedGround personnelCause
Inadequate substantiation process,insuff reviewCompany/operator mgmtFactor
Communications - not maintainedGround personnelCause

Analysis

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.

Factual narrative

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.

Aircraft

Registration
N627AW
Reported as
Airbus Industrie A-320-231 (A320-231)
Category
Airplane
Serial number
066
Airframe hours
32,206
Engine
Int'l Aero En V2500-A1, 24,800 lbs thrust, turbo fan
Damage
Substantial damage
Flight
Part 121
Operator
America West Airlines, Inc.
Registered owner
Wilmington Trust Company Trust
Airworthiness certificate
Standard, Transport
Last inspection
Continuous airworthiness · September 23, 1999 · 199 hours before
Departed
PHX
Destination
TUC · Tucson, AZ
Flight plan
IFR
Airport
PHX · Phoenix Sky Harbor Int'L

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

As NTSB recorded them. NTSB leaves out names.

Role
Pilot
Certificates
Commercial, Airline transport
Airplane ratings
Single-engine land, Multi-engine land
Instrument ratings
Airplane
Medical
Class 1, Valid Medical--no waivers/lim.
Seat
Left
Flight hours
18,300 total · 4,200 in this make and model · 178 in the last 90 days · 48 in the last 30 days

Weather

Conditions
Visual (VMC) · Day
Wind
100° at 7 knots
Visibility
10 statute miles
Lowest ceiling
None
Temperature
75 °F, dew point 34 °F
Altimeter
29.00 inHg
Observed at
PHX

FAA reports on this event · 1

The FAA’s own accident and incident reports, matched to the aircraft by N-number and date.