NTSB Identification: DEN93LA064.
The docket is stored on NTSB microfiche number 50858.
Accident occurred Sunday, May 30, 1993 in BUENA VISTA, CO
Probable Cause Approval Date: 11/03/1993
Aircraft: SCHEMPP-HIRTH NIMBUS II, registration: N173
Injuries: 1 Serious.

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

DURING THE TAKEOFF ROLL THE PILOT WENT FROM NEGATIVE TO POSITIVE FLAPS AFTER THE CONTROLS BECAME EFFECTIVE. THE FLAP TRANSITION WAS RAPID AND THE GLIDER BEGAN TO OSCILLATE IN PITCH. THE OSCILLATIONS BECAME DIVERGENT AND THE GLIDER ROLLED OFF ON A WING AND COLLIDED WITH THE GROUND SHORTLY AFTER THE SAFETY ROPE PARTED. THE PILOT STATED THAT HE WENT FROM NEGATIVE TO POSITIVE FLAPS TOO QUICKLY RESULTING IN LOSS OF CONTROL.

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

FAILURE TO FOLLOW PROCEDURES AND DIRECTIVES WHEN OPERATING THE FLAPS.

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