Narrative:

During a part 91 pleasure flight I experienced a runaway lateral trim failure. A precautionary landing was made in an open field to assess the failure. After set down; full down collective was applied and power was reduced to flight idle. Within a few seconds the aircraft settled and rocked backwards in soft terrain which caused a tail rotor strike.

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Original NASA ASRS Text

Title: AN HU500E TAIL ROTOR MADE GND CONTACT WHEN THE ACFT WAS TIPPED BACKWARD FOLLOWING A RUNAWAY LATERAL TRIM FAILURE.

Narrative: DURING A PART 91 PLEASURE FLT I EXPERIENCED A RUNAWAY LATERAL TRIM FAILURE. A PRECAUTIONARY LNDG WAS MADE IN AN OPEN FIELD TO ASSESS THE FAILURE. AFTER SET DOWN; FULL DOWN COLLECTIVE WAS APPLIED AND PWR WAS REDUCED TO FLT IDLE. WITHIN A FEW SECONDS THE ACFT SETTLED AND ROCKED BACKWARDS IN SOFT TERRAIN WHICH CAUSED A TAIL ROTOR STRIKE.

Data retrieved from NASA's ASRS site as of January 2009 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.