Aviation Accident Summaries

Aviation Accident Summary CHI03IA055

Indianapolis, IN, USA

Aircraft #1

N303TZ

Boeing 737-83N

Analysis

The airplane sustained minor damage when it struck a deicing truck as it was being towed back to the gate. No injuries occurred. The operator reported, "The de-ice truck had re-positioned itself off of the left wing and forward, waiting to de-ice another aircraft. The left wing walker left his post upon request of the tug driver to scrape the snow off the lead in line with his boot. The aircraft impacted the de-ice truck, dragging it approximately 15 feet. The truck went up on two wheels and was pinned at a 45-degree angle. The tow was stopped and appropriate calls made." Visibility was 1 and 1/2 statute mile and present weather was light snow and mist. The operator's procedures current at the time of the accident stated, "3. The tow tug operator will: a. Ascertain exactly where the aircraft is to be towed and positioned, and know (or view) the precise route to be taken. ... d. Undertake or continue a towing/pushing procedure only when visual contact with all necessary guidemen is possible. Obstructed vision is the 'signal' to stop and re-establish the necessary guidemen contacts."

Factual Information

On January 16, 2003, about 0815 eastern standard time, a Boeing 737-83N, N303TZ, operated by American Trans Air (ATA) as Flight 1801, was being towed back to gate C9 at the Indianapolis International Airport (IND), near Indianapolis, Indiana, when it struck a deicing truck. The airplane sustained minor damage. The 2 flight crewmembers, 4 cabin crewmembers and 73 passengers were uninjured. The two deicing truck occupants were uninjured. The scheduled domestic passenger flight was operating under 14 CFR Part 121 on an IFR flight plan. Instrument meteorological conditions prevailed. The flight, destined for Chicago Midway Airport, Chicago, Illinois, was pushed back from the gate, was deiced for its flight, and was being towed back to the gate for a passenger with a medical concern. The captain stated: 1300z De-ice and anti-ice completed with holdover start time at 1248z. Near anti-ice completion Senior [cabin crewmember] called to advise we had an ill passenger who wanted off. Called Ops for a tow in. While awaiting tow crew the Senior called again to say the passenger was OK and wanted to stay on. I asked for the Cabin crew's opinion of the passenger's condition and they verified that he appeared to be OK to continue. I advised Senior [cabin crewmember] that any in-flight problem would result in continuing to Chicago as it was north of the snow line with clear weather. During the call to Ops to wave-off the tow crew the Senior called again to advise the passenger wanted off. I now decided the passenger was going to deplane regardless of further indecision on his part and Senior [cabin crewmember] agreed. 1310z Tow crew arrived, we verified that they were hooked up with a bypass pin and coordinated with Ground Control. The 150 or so yards back to the gate appeared to be clear. About halfway to the gate we felt a movement that we interpreted as the aircraft sliding briefly and thought the tug was losing traction. A moment later I saw a marshaller in front of the tug signaling an emergency stop. I transmitted on the intercom 'Stop, he is signaling you to stop.' The aircraft stopped and I asked the tug driver what happened. I did not receive a response. I tried several more times with no response. I looked around and saw that the left outboard wing had struck a Signature de-ice truck. The truck was tilted up on two wheels and held by the wing. With no answer from the ramp lead I called Ops, described our situation and requested that we get Maintenance on the headset immediately for evaluation. Maintenance advised that there was no damage to the wing fuel bladder area and that no fuel was leaking from either the aircraft or the truck. He also said the truck appeared to be firmly wedged under the wing and was stable. The operator reported: The de-ice truck had re-positioned itself off of the left wing and forward, waiting to de-ice another aircraft. The left wing walker left his post upon request of the tug driver to scrape the snow off the lead in line with his boot. The aircraft struck the de-ice truck, dragging it approximately 15 feet. The truck went up on two wheels and was pinned at a 45-degree angle. The tow was stopped and appropriate calls made. The two occupants of the truck exited the high side of the vehicle with assistance, no injuries. All Passengers were deplaned out of L1, ten at a time, with no injuries. The aircraft sustained minor damage. At 0755, the recorded IND weather was: Wind 120 degrees at 5 knots; visibility 1 and 1/2 statute mile; present weather light snow, mist; sky condition broken 1,300 feet, overcast 3,000 feet; temperature -7 degrees C; dew point -8 degrees C; altimeter 30.25 inches of mercury. Excerpts from the ATA General Maintenance Manual current at the time of the accident stated: 3. The tow tug operator will: a. Ascertain exactly where the aircraft is to be towed and positioned, and know (or view) the precise route to be taken. b. Be familiar with conditions which influence the HOW, WHERE, and WHY conditions under which the aircraft will be handled by the tow tug. c. Note all potential clearance problems: (1) Obstructions to be avoided. (2) Overhead obstacles. (3) Portable equipment and/or stands which may be positioned in the path the aircraft is to follow (even though the aircraft path or guide may be painted on the ramp or floor). d. Undertake or continue a towing/pushing procedure only when visual contact with all necessary guidemen is possible. Obstructed vision is the 'signal' to stop and re-establish the necessary guidemen contacts. Subsequent to the accident the operator issued an "Aircraft Ground Damage Prevention Directive." Excerpts from the directive stated: STATION MANAGER/DIRECTOR DAILY PRESSENCE ON THE RAMP ... I expect and require that all of you spend at least one hour per day on our ramps, and that this activity be a continuous and very high priority item during the course of your workday schedule. During this time, you should observe our employees and our vendor personnel to ensure they are following procedures and that the equipment in use is mechanically safe. ... TEAM BRIEFINGS - PLANE TALK IMPLEMENTATION Recognizing the fact that good communication is important to safe operations. I have directed that we implement the process of conducting team briefings prior to each and every pushback and block-in operation. In order that these briefings cover all required areas, I have approved the use of a laminated 'Plane Talk' briefing card. These cards will be distributed to all stations ... . Station Managers/Directors should emphasize use of these cards during the course of their daily ramp observations. The operator's Safety Programs Manager stated that the directive was sent to "all station managers and directors. A similar document was sent to maintenance management. We are in the process of incorporating this into our Ground Damage Abatement Plan."

Probable Cause and Findings

The ground tow personnel not maintaining clearance from the de-icing vehicle during the tow back to the gate. Factors were the de-icing vehicle that parked by the airplane's left wing, the ground personnel not following the operator's towing procedures/directives.

 

Source: NTSB Aviation Accident Database

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