Aviation Accident Summaries

Aviation Accident Summary FTW98LA351

DENVER, CO, USA

Aircraft #1

N302ML

Airbus Industrie A-320-231

Analysis

The aircraft was pushed back from the gate and the crew set the parking brake. They notified the ground crew that they were cleared to disconnect the tug from the aircraft. The flight crew received a clearance by Ramp Control and began to taxi. The nose wheel of the aircraft then ran over one of the ground crewman's legs. According to the injured crewman, the tow bar connection to the aircraft was jammed. He disconnected the tow bar from the tug, and went to release the tow bar from the airplane's nose. He noticed the aircraft start to move, then roll over his legs. According to him, at no time following his braking instructions to the flight crew did he give them a clearance signal to initiate taxi. According to cockpit voice transcripts, a crew member replied, 'I apologize, I thought we were clear' after being told of the accident. The tow bar was still attached to the aircraft and the tug was still directly in front of the aircraft immediately following the accident. Neither the airline nor the ramp contractor's pushback procedures provide instructions for communications should there be a problem with the tow bar disconnect process. This was a contract operation with a weekly frequency.

Factual Information

On August 8, 1998, at 1455 mountain daylight time, an Airbus A320-231, operated by Prime Air as TransMeridian Airlines flight 1341, was not damaged when it taxied over the leg of a ground crewman during initial taxi following push back for departure at Denver International Airport, Denver, Colorado. The airline transport rated pilot and first officer, four flight attendants and 174 passengers were not injured; however, the ground crewman received serious injuries. The aircraft was being operated as a non-scheduled international passenger flight under Title 14 CFR Part 121, and visual meteorological conditions prevailed. An IFR flight plan was filed for the flight to Cancun, Mexico. According to the captain, after the aircraft was boarded, they experienced an APU failure, which required starting engine #2 at the gate prior to push back. After starting the #2 engine, the aircraft was pushed back from the gate and the flight crew started the #1 engine. They set the parking brake while at 50% power (N2), and notified the ground crew that they were cleared to disconnect the tug from the aircraft, to which they acknowledged. No further communications were held between the flight and ground crew following the ground crewman's instructions to the flight crew to set the parking brake. The flight crew received a clearance to taxi by Ramp Control and recalled that the area appeared clear. Immediately after beginning to taxi, the captain "felt something wrong with the aircraft." The first officer stated that his "vision was inside the cockpit" when he "heard a crunching or rubbing sound" immediately after beginning to taxi. The first officer looked outside the cockpit and did not see the tug or any ground crewman. The flight crew set the parking brake, and the tug driver announced to them over the intercom that they had just injured someone from the ground crew. In a statement following the accident, the injured ground crewman, Trenton Starry, stated that after removing ground power per the captain's request, the push back was initiated. Upon entering the service road, he advised the captain that they were clear to start the #1 engine and to set the brakes, to which the captain acknowledged. The captain then cleared him to disconnect the tow bar from the aircraft. When he went to disconnect the tow bar, the connection to the aircraft was jammed. He disconnected the tow bar from the tug, and went back to the aircraft's nose gear with the intention of releasing the tow bar from the airplane. The next thing he remembered was the aircraft "rolling over [his] legs." According to him, at no time following his braking instructions to the flight crew did he give them a signal that they were cleared to initiate taxi. The operator of the push back stated that he observed Mr. Starry give the captain the signal to set the brakes and then attempt to release the tow bar. The tow bar was jammed, so the driver put the tug in reverse to ease tension. Once the tow bar was released from the vehicle, he observed Mr. Starry approach the aircraft to remove the tow bar from the airplane. He noticed the aircraft begin to move, and the nose gear then rolled over Mr. Starry's legs. The tug operator recalled borrowing Mr. Starry's headsets to notify the crew of the accident. According to cockpit voice transcripts, the tug operator said to the crew, "You just ran over my guy down here," to which one of the crew members replied, "I apologize, I thought we were clear." According to several witnesses, the aircraft traveled approximately 8 feet before stopping. The tow bar was still attached to the aircraft and the tug was still directly in front of the aircraft immediately following the accident. This was a contract operation with a weekly frequency. According to the "Pushback/Headset Communications Procedures" outlined by Integrated Airline Services (the ramp contractor), once the tow bar is disconnected from the nose of the aircraft, the tug is to be "backed clear and in view of the flight crew." The ground crew is then instructed to "advise flight 'you are clear to start #2.'" The ground crewmember is instructed to continue wearing the headsets until both engines are operating, and until the flight crew has advised that they have "2 good engine starts," and that it is "ok to disconnect headset." TransMeridian Airlines' "A-320 Aircraft Operating Manual" states that "When ready to taxi, obtain 'all clear' signal and salute ground crew and then contact ground control for taxi clearance." Neither the airline nor the ramp contractor's pushback procedures provide instructions for communications should there be a problem with the tow bar disconnect process.

Probable Cause and Findings

The failure of the flight crew to comply with braking instructions after being instructed by ground personnel.

 

Source: NTSB Aviation Accident Database

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