No fatalities

Sioux City Airport Takeoff Accident (N974Z)

Sioux City, United States of AmericaTakeoff (climb)

On December 27, 1968, a Douglas DC-9 (registration N974Z) operated by Ozark Air Lines was involved in an aviation accident near Sioux City, United States of America during takeoff. No fatalities were reported. Investigators recorded the probable cause as: A stall near the upper limits of ground effect, with subsequent loss of control as a result of aerodynamic and weight penalties of airfoil icing. The flight crew failed to have the airfoil ice removed prior to the attempted take-off from Sioux City. This summary draws on records from the Bureau of Aircraft Accidents Archives (B3A); 1 related events involving the same aircraft type or operator are linked below.

Sourcesthe Bureau of Aircraft Accidents Archives (B3A)Primary reportUpdated 2026-06-12Data APIEditorial standards
Aircraft registered N974Z
Aircraft registered N974Z. Photo: Bill Larkins / CC BY-SA 2.0, via Wikimedia Commons

An aircraft crashed while taking off from Sioux City Airport, Iowa, with no fatalities. The flight crew was aware of wing ice, and the aircraft rolled violently before the captain aborted the takeoff.

Incident Overview and Casualties At approximately 0711LT, an aircraft crashed while taking off from Sioux City Airport, Iowa. The accident resulted in no fatalities. Of the 64 passengers and four crewmembers on board, 10 passengers were hospitalized with minor injuries, and three crew members sustained serious injuries. The aircraft was destroyed in the crash, and no fire occurred. ## Takeoff Sequence Flight 982 began its takeoff on Runway 35 with the flight crew aware that ice was present on the wings. After the aircraft lifted off, the first officer selected the landing gear to the up position, and the captain began turning off the landing and taxi lights. As the landing gear began to retract, the aircraft rolled abruptly and violently to the right, reaching an estimated bank angle of 900. The captain applied additional power and left rudder in an attempt to level the wings. When no immediate response was noted, he then applied left aileron. With the application of left aileron, the right wing came up; however, the roll continued to the left until the left wing contacted the runway. At this point, the captain discontinued the takeoff. He succeeded in leveling the wings prior to final ground contact, approximately 110 feet beyond the departure threshold of Runway 35. The aircraft came to rest in a grove of trees approximately 1,181 feet beyond the departure end of Runway 35.

Probable cause

A stall near the upper limits of ground effect, with subsequent loss of control as a result of aerodynamic and weight penalties of airfoil icing. The flight crew failed to have the airfoil ice removed prior to the attempted take-off from Sioux City. The Board also finds that the crew selected an improper takeoff thrust for the existing gross weight condition of the aircraft.