NTSB Identification: BFO92LA102.
The docket is stored on NTSB microfiche number 52893.
Accident occurred Wednesday, July 15, 1992 in SOUTHWICK, MA
Probable Cause Approval Date: 04/07/1995
Aircraft: BELL 47G, registration: N3109G
Injuries: 2 Uninjured.

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

THE PILOT WAS MAKING A RIGHT TURN DURING A HOVER-TAXI CHECK AS PART OF A POST-MAINTENANCE FLIGHT TEST. ACCORDING TO THE PILOT, THE HELICOPTER CONTINUED TO ROLL RIGHT (UNCOMMANDED), AND HE WAS UNABLE TO REGAIN CONTROL DESPITE USING LEFT CYCLIC INPUT. THE MAIN ROTORS STRUCK THE GROUND, AND THE HELICOPTER IMPACTED THE GROUND IN A NOSE DOWN, RIGHT BANK, ATTITUDE. EXAMINATION OF THE HELICOPTER INCLUDED A TEST OF THE HYDRAULIC DAMPERS WHICH WERE CONNECTED TO THE STABILIZER BAR ASSEMBLY. THE TEST REVEALED THAT THE DAMPERS WERE NOT ADJUSTED ADEQUATELY, WHICH RESULTED IN LITTLE TO NO RESPONSE TO CYCLIC CONTROL INPUT.

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

IMPROPER ADJUSTMENT OF THE STABILIZER CONTROL SYSTEM BY MAINTENANCE PERSONNEL.

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