What happened
The FAA’s narrative, in sentence case. The FAA writes it in capitals and removes private details.
(-23) After making a pass while spraying a crop, the engine hesitated, a few seconds later while attempting to turn, the engine quit running. Altitude was approximately 50'. The helicopter impacted the terrain causing substantial damage. (.4) the aircraft experienced a total loss of engine power while maneuvering during agricultural spraying. The aircraft impacted terrain during a forced landing. Examination of the engine by a federal aviation administration inspector showed the engine to rotate and to have compression in all cylinders. Electrical continuity was established from the magnetos and through the harness. There was no fuel found in the fuel line connecting the fuel tank to the engine driven pump. The engine driven and electric fuel pumps rotated and were then disassembled but damage was found on the impeller of the fuel pumps. The carburetor bowls contained 1/3 fuel. Approximately three gallons of fuel was drained from the helicopter fuel tank with no external leakage visually present. The fuel tank port is located at the forward end of the fuel tank. The Hiller UH-12E flight manual states, 'operating with fue l indicator in the yellow arc during sideward or rearward flight may result in loss of power'. The yellow arc indicates a fuel range from 0 to 2.9 gallons, 0 to 11 liters, 0-17 lbs. Of fuel. The Hiller UH-12E flight manual supplement states, 'consideration should be given to hoisting loads off the ground vertically as pulling or dragging loads off in other than a vertical direction can cause the helicopter to exceed the certified normal flight body-angle and unusable fuel envelope'.
As the FAA filed it
(-23) AFTER MAKING A PASS WHILE SPRAYING A CROP, THE ENGINE HESITATED, A FEW SECONDS LATER WHILE ATTEMPTING TO TURN, THE ENGINE QUIT RUNNING. ALTITUDE WAS APPROXIMATELY 50'. THE HELICOPTER IMPACTED THE TERRAIN CAUSING SUBSTANTIAL DAMAGE. (.4) THE AIRCRAFT EXPERIENCED A TOTAL LOSS OF ENGINE POWER WHILE MANEUVERING DURING AGRICULTURAL SPRAYING. THE AIRCRAFT IMPACTED TERRAIN DURING A FORCED LANDING. EXAMINATION OF THE ENGINE BY A FEDERAL AVIATION ADMINISTRATION INSPECTOR SHOWED THE ENGINE TO ROTATE AND TO HAVE COMPRESSION IN ALL CYLINDERS. ELECTRICAL CONTINUITY WAS ESTABLISHED FROM THE MAGNETOS AND THROUGH THE HARNESS. THERE WAS NO FUEL FOUND IN THE FUEL LINE CONNECTING THE FUEL TANK TO THE ENGINE DRIVEN PUMP. THE ENGINE DRIVEN AND ELECTRIC FUEL PUMPS ROTATED AND WERE THEN DISASSEMBLED BUT DAMAGE WAS FOUND ON THE IMPELLER OF THE FUEL PUMPS. THE CARBURETOR BOWLS CONTAINED 1/3 FUEL. APPROXIMATELY THREE GALLONS OF FUEL WAS DRAINED FROM THE HELICOPTER FUEL TANK WITH NO EXTERNAL LEAKAGE VISUALLY PRESENT. THE FUEL TANK PORT IS LOCATED AT THE FORWARD END OF THE FUEL TANK. THE HILLER UH-12E FLIGHT MANUAL STATES, 'OPERATING WITH FUE L INDICATOR IN THE YELLOW ARC DURING SIDEWARD OR REARWARD FLIGHT MAY RESULT IN LOSS OF POWER'. THE YELLOW ARC INDICATES A FUEL RANGE FROM 0 TO 2.9 GALLONS, 0 TO 11 LITERS, 0-17 LBS. OF FUEL. THE HILLER UH-12E FLIGHT MANUAL SUPPLEMENT STATES, 'CONSIDERATION SHOULD BE GIVEN TO HOISTING LOADS OFF THE GROUND VERTICALLY AS PULLING OR DRAGGING LOADS OFF IN OTHER THAN A VERTICAL DIRECTION CAN CAUSE THE HELICOPTER TO EXCEED THE CERTIFIED NORMAL FLIGHT BODY-ANGLE AND UNUSABLE FUEL ENVELOPE'.
NTSB investigation
The NTSB’s investigation of this event, with its probable cause and findings. Matched to this report by N-number and date.