CHI08LA051

NTSB accident investigation · Bombardier CL-600-2B19 · Chicago, IL · December 17, 2007

Accident · Serious injuriesLimited investigationFinal report
Date
December 16, 2007, 18:55 local (Dec 17, 2007, 00:55 UTC)
Place
Chicago, IL
Injuries
1 serious, 32 uninjured; on the ground: 1 serious
Damage
Substantial damage
Phase of flight
Taxi
Aircraft
N918SWBombardier CL-600-2B19
Weather
Visual (VMC) · Night
Status
Completed · report May 28, 2008
Report
Approved by Office Director
Parties
FAA-O'Hare FSDO
Case key
67319

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 tug driver's failure to yield the right-of-way to the airplane prior to crossing the active taxiway as required by airport procedures, and his subsequent failure to maintain clearance with the airplane. A contributing factor was the presence of the tug on the taxiway at the time the airplane passed the service road intersection. Additional factors were the wet pavement and the night lighting conditions.

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 - from landing
Procedures/directives - not complied withDriver of vehicleCause
Clearance - not maintainedDriver of vehicleCause
Object - vehicleFactor
Terrain condition - wetFactor
Light condition - nightFactor

Analysis

The captain reported that the flight had landed and was taxiing to the gate when the accident occurred. He stated that as they passed an airport service road - taxiway intersection, the airplane hit something. The captain brought the airplane to a stop, but at the time the flight crew could not see what they hit. He continued, turning left onto the next intersecting taxiway. At that time he saw the overturned tug along the south edge of the taxiway at the service road intersection. He taxied to the assigned gate and deplaned the passengers without further incident. Witnesses in a van behind the tug reported that the tug did not stop short of the taxiway and continued to move onto the taxiway as the airplane approached. The right wing of the airplane subsequently struck the tug and flipped it over. The tug driver was hospitalized for injuries received during the accident. He had no recollection of the events surrounding the accident. Witnesses recalled that the taxiway was wet at the service road intersection, but that it was not snowing at that time. The surface visibility about the time of the accident was 10 miles with no precipitation or restrictions to visibility. The airport Ground Motor Vehicle Operation Regulations Manual stated that, "All ground vehicle operators must yield the right-of-way to an aircraft in motion."

Factual narrative

On December 16, 2007, about 1855 central standard time, a Bombardier CL-600-2B19 airplane, N918SW, operated by Skywest Airlines as flight 6034, was substantially damaged when the right wing struck a tug while taxing to the gate after landing at O'Hare International Airport (ORD), Chicago, Illinois. The domestic scheduled passenger flight was conducted under 14 CFR part 121 on an instrument flight rules flight plan. Night visual meteorological conditions prevailed at the time of the accident. The 29 passengers, 1 cabin crew member and 2 flight crew members were not injured. The driver of the tug was seriously injured. The flight departed Dane County Regional Airport (MSN), Madison, Wisconsin, about 1800. The intended destination was ORD.

The captain reported that the flight landed on runway 22R and was taxiing eastbound on taxiway B en route to gate F6. Between intersecting taxiways A9 and A10, the airplane hit something. The captain brought the airplane to a stop, but at the time the flight crew could not see what they hit. He subsequently continued and turned left onto taxiway A10. At that time he saw the overturned tug along the south edge of taxiway B at the service road intersection. He taxied to the assigned gate and deplaned the passengers without further incident. A post flight inspection by the first officer revealed impact damage to the leading edge of the right wing, within 4 feet of the wing tip. The damage extended aft to the forward wing spar.

The tug was operated by Continental Airlines. The driver was hospitalized for injuries received during the accident. At the time of this report, he had no recollection of the events surrounding the accident.

A witness reported that he was driving on the service road when he realized that an airplane was going to pass by on the taxiway. He stopped his van to allow the airplane to pass. He stated that the tug driver may have realized that the airplane was coming at the last minute and tried to slam on the brakes. However, the tug continued to slide forward and the right wing of the airplane hit the left side of the tug, flipping it over.

A pilot riding in the same van as the previous witness reported that they were following the tug on the service road and had stopped at taxiway B to allow the airplane to pass. He stated that when he looked up a second later, the airplane was passing in front of his van and he noticed that the tug was still moving slowly. He reported that as the airplane's wing passed the service road it struck the tug and knocked it over.

Two individuals that arrived on-scene after the accident recalled that the taxiway was wet at the service road intersection, but it was not snowing at that time. One of them commented that the airport terminal lights were reflected by the wet pavement. They also noted that it was a dark, "dreary" night.

The ORD weather observation taken at 1851 noted that winds were from 280 degrees at 9 knots, gusting to 18 knots, with 10 miles visibility. No precipitation or restriction to visibility was indicated.

The O'Hare Airport Ground Motor Vehicle Operation Regulations Manual stated that, "All ground vehicle operators must yield the right-of-way to an aircraft in motion." In addition, the manual required, "No person operating a ground vehicle will cross a Taxiway without bringing the vehicle to a complete stop."

Aircraft

Registration
N918SW
Reported as
Bombardier CL-600-2B19
Category
Airplane
Serial number
7645
Airframe hours
14,195
Engines
General Electric CF34-3B1, 9,345 lbs thrust, turbo fanGeneral Electric CF34-3B1, 9,345 lbs thrust, turbo fan
Damage
Substantial damage
Flight
Part 121
Operator
Skywest Airlines Inc
Registered owner
Wells Fargo Bank Northwest
Airworthiness certificate
Standard, Transport
Last inspection
Continuous airworthiness · December 1, 2007
Departed
MSN · Madison, WI
Destination
ORD · Chicago, IL
Flight plan
IFR
Airport
ORD · Chicago O'Hare Intl, runway 22R, 7,500 × 150 ft, asphalt

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 · 2

As NTSB recorded them. NTSB leaves out names.

Role
Pilot
Age
35
Injuries
None
Certificate
Airline transport
Airplane ratings
Single-engine land, Multi-engine land
Instrument ratings
Airplane
Medical
Class 1, Without waivers/limitations
Last flight review
August 1, 2007
Seat
Left
Flight hours
6,337 total · 4,772 in this make and model · 227 in the last 90 days · 4 in the last 24 hours
Role
Co-pilot
Age
27
Injuries
None
Certificate
Commercial
Airplane ratings
Single-engine land, Multi-engine land
Instrument ratings
Airplane
Medical
Class 1, With waivers/limitations
Last flight review
July 1, 2007
Seat
Right
Flight hours
2,177 total · 366 in this make and model · 232 in the last 90 days · 6 in the last 24 hours

Weather

Conditions
Visual (VMC) · Night
Wind
280° at 9 knots, gusting 18
Visibility
10 statute miles
Lowest ceiling
1,400 ft broken
Temperature
19 °F, dew point 12 °F
Altimeter
30.06 inHg
Observed at
ORD