Tuesday, 20th of December, 1983

– United States of America

Ozark Air Lines Flight 650, a domestic scheduled passenger flight from Sioux City-Municipal Airport, IA (SUX/KSUX), to Sioux Falls Regional Airport (Jo Foss Field), SD (FSD/KFSD), operated with a McDonnell Douglas DC-9-31, registration N994Z, was landing at Sioux Falls when the right wing struck a snow plough on runway 03. The wing separated and the plane swerved off the runway.

The airplane sustained substantial damage. The five crew members and 81 passengers survived. The snow plow’s driver was fatally injured.

– Details:

Prior to departing Sioux City, Flight 650’s flight crew obtained weather conditions for the flight via Sioux City’s automatic terminal information service (ATIS) broadcast system. The ATIS report included reports of blowing snow at Sioux Falls.

Flight 650 departed Sioux City at 12:53 Central Standard Time, and climbed to an assigned altitude of 11,000 feet. At 13:06, the flight was handed off from Sioux City controllers to the Sioux Falls approach controller, who issued descent instructions to 3,400 feet and vectors to Runway 3 at Sioux Falls Regional Airport. Flight 650 was cleared for the approach at 13:11.

At 13:13, when Flight 650 was about 4 miles out from the airport, the Sioux Falls approach controller directed the flight to contact the airport tower. Flight 650’s captain acknowledged the instruction, but did not contact the tower. When Flight 650 was about 2.5 miles out, the Sioux Falls tower called the flight, and the captain responded. The tower then cleared Flight 650 to land, giving a runway visual range of 3,500 feet. The tower did not advise Flight 650 of snow removal operations in progress on Runway 3.

The flight crew first saw the ground and airport approach lights after descending to an altitude of 200 feet, and then saw the runway. Because the ATIS report had advised of blowing snow, and the flight crew was not advised of snow blowing operations, they were not surprised to see snow blowing across the runway.

About 1,000 feet beyond the threshold of Runway 3, the aircraft made a smooth touchdown and the pilots deployed the spoilers. The copilot began to apply reverse thrusters when the aircraft entered a cloud of snow. The DC-9’s right wing then struck a large snowsweeping vehicle on the runway. The impact ripped the right wing from the plane, destroying the snow plow and killing its driver. Leaking fuel from the wing briefly created a fireball that engulfed the airplane but rapidly died out. The plane spun through 180° before coming to rest off the runway to the left of the center line. Passenger evacuation was initiated through the front two doors. No passengers were injured in the evacuation, but two flight attendants suffered minor injuries.

– Cause:

“Inadequate Control Tower Service by Air Traffic Control Personnel. Factors relating to the accident were weather conditions; snow, obscuration, low ceiling; and vehicles on the runway.”