NTSB Identification: FTW91LA064.
The docket is stored on NTSB microfiche number 44331.
Accident occurred Saturday, April 27, 1991 in CORPUS CHRISTI, TX
Probable Cause Approval Date: 03/31/1993
Aircraft: BELL 47G4, registration: N1195W
Injuries: 2 Minor.

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

A COMMERCIAL PILOT WAS MANEUVERING A HELICOPTER TO CONTROL A HERD OF CATTLE. THE PILOT NOTICED AN INTERMITTENT BINDING IN THE LEFT QUADRANT OF THE CYCLIC CONTROL. HE NOTIFIED HIS FLIGHT LEADER OF HIS INTENTIONS TO LAND AND INSPECT THE HYDRAULIC SERVOS IN THE FLIGHT CONTROL SYSTEM, AND INITIATED A PRECAUTIONARY LANDING CLOSE TO THEIR MAINTENANCE SUPPORT VEHICLE. DURING THE LANDING FLARE, THE HELICOPTER PITCHED SHARPLY TO THE RIGHT REAR AS THE LATERAL CYCLIC CONTROL BECAME LOCKED. THE PILOT APPLIED FULL RIGHT PEDAL TO TRY TO CUSHION THE LANDING AND PREVENT THE HELICOPTER FROM ROLLING. THE HELICOPTER WAS DESTROYED UPON IMPACT WITH THE MESQUITE TREES. THE FAILED LATERAL SERVO HAD BEEN REPLACED BY AN UNQUALIFIED PERSON PRIOR TO THIS FLIGHT.

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

THE INITIAL RESTRICTED MOVEMENT AND EVENTUAL LOCKING OF THE CYCLIC CONTROL AS A RESULT OF THE FAILURE OF THE LATERAL SERVO. A FACTOR WAS THE INSTALLATION OF THE FAILED COMPONENT BY AN UNQUALIFIED PERSON.

Index for Apr1991 | Index of months