Casualties unknown

1989-04-27: Cessna 208A (N9637F) — Dupage Airport Authority — Mt. Zion, IL

Mt. Zion, IL, US

On April 27, 1989, a Cessna 208A (registration N9637F) operated by Dupage Airport Authority was involved in an aviation accident near Mt. Zion, IL. Investigators recorded the probable cause as: THE PILOT'S INTENTIONAL FLIGHT INTO KNOWN ADVERSE WEATHER. CONTRIBUTING FACTORS WERE THE PILOT'S POOR EVALUATION OF THE WEATHER INFORMATION GIVEN HIM BY THE AIR TRAFFIC CONTROLLERS. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive; 1 related events involving the same aircraft type or operator are linked below.

Sourcesthe U.S. National Transportation Safety Board (NTSB) historical archivePrimary reportUpdated 1781061362Data APIEditorial standards

A pilot departing Marion without a weather briefing encountered strong turbulence and windshear on approach. Despite flap and throttle adjustments, the aircraft became uncontrollable.

Incident Details

A pilot departed Marion without obtaining a weather briefing. During the approach, the pilot was advised that the last person making the approach had reported moderate to severe turbulence on final. The pilot was subsequently cleared to land and given wind conditions of 360 degrees at 30 knots, gusting to 40 knots. Additionally, the pilot was advised that another aircraft had reported a 20-knot windshear on final.

The pilot reported that after descending to 1,500 feet mean sea level (MSL), the aircraft encountered strong turbulence. The airspeed fluctuated wildly, ranging from stall speed to redline. Despite adjustments to the flaps and throttle, the pilot was unable to maintain control, and the airplane became uncontrollable.

Weather Conditions

Wind was reported as 360 degrees at 30 knots, gusting to 40 knots. A previous aircraft reported moderate to severe turbulence on final, and another reported a 20-knot windshear on final.

Pilot Actions

The pilot attempted to regain control by adjusting flap settings and throttle position, but these efforts were unsuccessful in counteracting the extreme turbulence and windshear encountered.

Investigation report by the U.S. National Transportation Safety Board (NTSB) historical archive. Original record: https://carol.ntsb.gov/event/20001213X28057. This page is a structured re-presentation; facts and quotes are in the National Transportation Safety Board (NTSB), United States.