Boeing 737-7H4 N469WN

Summary

On 22 December 2011 at about 21:37 local time, a Boeing 737-7H4 registered N469WN, operated by Southwest Airlines Co, was involved in an incident near Denver, Colorado, United States. 133 people were on board and nobody was injured. The aircraft was slightly damaged. The NTSB has published a probable cause for this accident; it is quoted in full below.

Date

22 December 2011 at 21:37

Classification

Incident

Location

Denver, Colorado, United States

Nearest airport

Denver International Airport (DEN)

Coordinates

39.7502, -104.9996

Aircraft

Boeing 737-7H4

Registration

N469WN

Category

Airplane

Engines

2

Operator

Southwest Airlines Co

Operating rule

Part 121: Air Carrier

Phase of flight

Not recorded

Route

Denver → Los Angeles

Aircraft damage

Minor

Weather

IMC

Light

Day

NTSB number

CEN12IA123

Nobody was injured.

The snowplow operator’s incapacitation due to fatigue, which resulted in the snowplow contacting a parked airplane. Contributing to the incident was the company’s lack of a policy regarding employee fatigue.

Quoted verbatim from the NTSB record. This site does not paraphrase or interpret it.

Read the full NTSB narrative

The passengers and the flight crew were seated, and the ground crew was preparing to push the airplane away from the gate. The snowplow was conducting snow removal operations in clean-up mode. According to a witness, the snowplow was traveling eastbound behind the airplane and just north of the vehicle service road. The snowplow passed the airplane and then initiated a gradual turn to the right. The snowplow continued around 180 degrees and hit the airplane on the left side near the empennage. The snowplow operator reported that he fell asleep while driving. The investigation revealed that the snowplow operator reported for his shift at 1730 the day before the incident and worked until 0200 the next morning. The snowplow operator slept in his supervisor’s vehicle, which was actively involved in the snow removal operations. At 0800, the snowplow operator resumed snow removal operations, and he had been working for about 6.5 hours when the incident occurred. The snowplow operator had an opportunity to sleep for 6 hours in his supervisor’s vehicle; however, since the vehicle was being operated, he probably did not get uninterrupted sleep and most likely got less than 6 hours of sleep. Although the investigation was unable to determine how long the snowplow operator had been awake on the day before the accident or how long he had slept in his supervisor’s vehicle, he was most likely fatigued. The company did not have, and was not required to have, guidance or a policy addressing fatigue management.

Quoted verbatim from the NTSB record.