Aviation Accident Summaries

Aviation Accident Summary FTW94LA144

OSAGE, AR, USA

Aircraft #1

N90469

HILLER UH-12E

Analysis

ACCORDING TO THE PILOT, THE HELICOPTER WAS SERVICED WITH 30 GALLONS OF FUEL FOR AN AERIAL APPLICATION FLIGHT TO DISPENSE 100 GALLONS OF PESTICIDES. AFTER A 45 MINUTE SORTIE, THE HELICOPTER WAS EN ROUTE BACK TO THE LOADING SITE, OVER HEAVILY WOODED MOUNTAINOUS TERRAIN, WHEN THE PILOT EXPERIENCED A LOSS OF ENGINE POWER. THE ENGINE REGAINED POWER TEMPORARILY, AND LOST POWER FOR A SECOND TIME 5 TO 8 SECONDS LATER. THE PILOT AUTOROTATED ABOVE THE TREE TOPS AND SETTLED THROUGH THE TREES COMING TO REST IN AN UPRIGHT POSITION. THERE WAS NO EVIDENCE OF A FUEL SPILL AND NO FUEL WAS FOUND IN THE FUEL CELL. THE AVERAGE FUEL BURN RATE IS 25 TO 26 GALLONS PER HOUR. THE ENGINE WAS SUCCESSFULLY RUN IN AN ENGINE TEST CELL.

Factual Information

On May 4, 1994, at 1830 central daylight time, a Hiller UH-12E helicopter, N90469, was substantially damaged following a loss of engine power near Osage, Arkansas. The airline transport rated pilot sustained minor injuries. Visual meteorological conditions prevailed for the aerial application flight. According to the operator, the turbine powered helicopter was supporting a gypsy moth eradication program within the Ozark National Forest. The pilot stated that the helicopter was serviced with 100 gallons pesticides and 30 gallons of Jet A fuel for the ninth sortie of the day. Approximately 45 minutes later, while en route back to the load site, the engine lost power. The pilot stated that he entered autorotation, and the engine auto reignite restarted the engine. The pilot added that he turned towards an open field to make a precautionary landing, and approximately 5 to 8 seconds later, the engine lost power for the second time. The pilot reentered an autorotation to the heavily wooded area ahead and was able stop all forward motion above the tree tops, settling through the trees. After falling 40 to 50 feet, the helicopter came to rest in the upright position lodged between the tree trunks. According to the operator, the fuel cell and the fuel lines were not compromised during the crash sequence. No fuel was found in the fuel cell, and there was no evidence of a fuel spill on the ground. According to the engine manufacturer, the average fuel burn rate is 25 to 26 gallons per hour. A successful engine run was accomplished in a test cell, and no anomalies were found with either the fuel control or associated fuel system components.

Probable Cause and Findings

FUEL EXHAUSTION DUE TO THE PILOT'S FAILURE TO REFUEL AND THE LACK OF SUITABLE TERRAIN FOR A FORCED LANDING.

 

Source: NTSB Aviation Accident Database

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