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Last updated: 1 December 2021
Date:Monday 2 October 2017
Type:Silhouette image of generic B737 model; specific model in this crash may look slightly different
Boeing 737-7H4 (WL)
Operator:Southwest Airlines
Registration: N930WN
MSN: 36636/2784
First flight: 2009-01-14 (8 years 9 months)
Total airframe hrs:30104
Engines: 2 CFMI CFM56-7B24
Crew:Fatalities: 0 / Occupants: 5
Passengers:Fatalities: 0 / Occupants: 79
Total:Fatalities: 0 / Occupants: 84
Aircraft damage: Substantial
Aircraft fate: Repaired
Location:Chicago-Midway Airport, IL (MDW) (   United States of America)
Phase: Standing (STD)
Nature:Domestic Scheduled Passenger
Departure airport:Chicago-Midway Airport, IL (MDW/KMDW), United States of America
Destination airport:Omaha-Eppley Airfield, NE (OMA/KOMA), United States of America
Southwest Airlines flight 681, Boeing 737-700, N930WN, was struck by an unmanned tug while boarding was ongoing at Chicago Midway Airport (KMDW), Chicago, Illinois, USA. There were no injuries to the 84 passengers and crew onboard. The airplane received substantial damage to the lower fuselage skin, frames and stringers over an area about 3 feet by 3 feet.

A ramp agent was driving a covered baggage tug with two baggage carts in tow between Gates B22 and B24 when the tug made contact with two staged baggage carts. The ramp agent jumped off the tug as the tug continued to accelerate forward. The now unmanned baggage tug struck additional ground support equipment before striking the fuselage of the accident airplane at Gate B22. The ramp agent stated afterwards that he could not get the tug to stop and thought running the tug into the staged baggage carts would stop or at least slow the tug down.

Examination of the baggage tug after the event revealed there was a mechanical failure of the fuel governor which resulted in the runaway. The runaway could have been stopped by either turning the ignition key off or using the manual shut down lever on the front cover. There was no guidance in the Ground Operations Training Manual related to how ramp personnel should handle mechanical failures of ground support equipment.

Probable Cause:

Probable Cause: "The mechanical failure of the tugs fuel governor, which made it difficult for the ramp agent to stop the tug. Contributing to the accident was the lack of guidance on how ground personnel were to handle vehicle malfunctions."

Accident investigation:
Investigating agency: NTSB
Status: Investigation completed
Duration: 2 years and 8 months
Accident number: DCA18CA001
Download report: Final report

Damaged on the ground


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This map shows the airport of departure and the intended destination of the flight. The line between the airports does not display the exact flight path.
Distance from Chicago-Midway Airport, IL to Omaha-Eppley Airfield, NE as the crow flies is 675 km (422 miles).
Accident location: Approximate; accuracy within a few kilometers.

This information is not presented as the Flight Safety Foundation or the Aviation Safety Network’s opinion as to the cause of the accident. It is preliminary and is based on the facts as they are known at this time.
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