N933B – BELL 47G – 1994-05-18 NTSB Accident Report

On May 18, 1994, a Bell 47G (N933B) was involved in an incident near Sulphur, OK. All 1 person aboard were uninjured. The aircraft sustained substantial damage.

The National Transportation Safety Board determined the probable cause of this incident to be: THE LOSS OF ENGINE POWER DUE TO THE FAILURE OF AN ENGINE ACCESSORY OIL PUMP GEAR. A FACTOR WAS THE LACK OF SUITABLE TERRAIN FOR THE AUTOROTATION.

On May 18, 1994, at 1830 central daylight time, a Bell 47G, N933B, sustained substantial damage during a forced landing near Sulphur, Oklahoma. The commercial pilot did not receive injuries. Visual meteorological conditions prevailed for the local aerial application flight.

The pilot reported a total loss of engine power at 50 feet above the ground during the initial phase of a turn-around maneuver. He further said that trees in the area and the height of the helicopter hindered his completion of a successful autorotation. The helicopter bounced during the hard landing and the main rotor blade flexed and severed the tailboom.

During a telephone interview the operator reported the total loss of engine power was due to the failure of the oil pump drive gear in the accessory case.

This incident is documented in NTSB report FTW94LA166. AviatorDB cross-references NTSB investigation data with FAA registry records to provide comprehensive safety information for aircraft N933B.