NTSB Identification: CHI99IA144.
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Incident occurred Monday, April 26, 1999 in WHEELING, IL
Probable Cause Approval Date: 08/14/2001
Aircraft: Cessna 206H, registration: N42122
Injuries: 2 Uninjured.

NTSB investigators used data provided by various sources and may not have traveled in support of this investigation to prepare this aircraft incident report.

During the run-up flight control checks prior to takeoff, the pilot experienced an aileron control failure. He was unable to obtain left aileron up movement. Inspection determined that the aileron had 4 degrees of up travel. Normal travel was 20 degrees +/- 2 degrees. Further inspection revealed that one of the aileron control bellcrank stop bolt/jam nut assemblies was loose allowing the stop bolt to rotate out of the threaded boss. This restricted the aileron movement. The three other stop bolt/jam nut assemblies were also inspected and were found to be loose. The airplane was a 1999 model, s/n 25, which had a total of approximately 11 hours on it at the time of the incident. In response to this incident Cessna Aircraft Company issued Special Service Project SSP99-27-02. On June 21, 1999, the Federal Aviation Administration issued Airworthiness Directive, 99-13-04, effective July 13, 1999. The AD requires '...inspecting the left and right wing aileron control bellcrank stop bolts and lock nuts for flush and tight contact with the surface of the threaded boss on each end of the yoke assemblies, and accomplishing follow-on and corrective actions, as applicable.'

The National Transportation Safety Board determines the probable cause(s) of this incident to be:

improper installation of the aileron control bellcrank stop bolts and lock nuts during the manufacturing process which resulted in a binding aileron control surface.

Full narrative available

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