SULPHUR, OK, USA
N933B
BELL 47G
A TOTAL LOSS OF ENGINE POWER OCCURRED AT 50 FEET ABOVE THE GROUND DURING THE INITIAL PHASE OF A TURN-AROUND MANEUVER. TREES HINDERED THE PILOT'S COMPLETION OF THE AUTOROTATION. THE HELICOPTER BOUNCED DURING THE LANDING AND THE MAIN ROTOR BLADE FLEXED AND SEVERED THE TAILBOOM. AN EXAMINATION OF THE ENGINE BY THE OPERATOR REVEALED THE FAILURE OF AN ENGINE ACCESSORY OIL PUMP GEAR.
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.
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.
Source: NTSB Aviation Accident Database
Aviation Accidents App
In-Depth Access to Aviation Accident Reports
