WHITEVILLE, NC, USA
N707EX
Aerospatiale SA315B
During an aerial application flight, the low fuel level warning light illuminated. The pilot started his stop watch according to the airplane flight manual and about 6 minutes later while en route to refuel, the engine quit due to fuel exhaustion. While attempting to clear trees below the pilot purposely bleed the main rotor rpm which resulted in a hard landing. Post crash, fuel was added to the fuel tank and the engine was started and found to operate normally. Post accident testing revealed that when all fuel was drained from the full fuel tank the fuel gauge in the cockpit would register full unless the side of the fuel tank was contacted to dislodge the stuck fuel gauge transmitter. The pilot stated that he has brought the stuck fuel transmitter problem to the attention of the operator but review of the maintenance records revealed no record of the transmitter being repaired or replaced. Review of the flight manual revealed that once the low fuel light illuminates, to fly no longer than 10 minutes.
On January 25, 1997, about 1500 eastern standard time, an Aerospatiale SA315B helicopter, N707EX, registered to Roberts Aircraft Company, operated by Gold Kist, Inc., was substantially damaged during an autorotative landing in a wooded area near Whiteville, North Carolina. Visual meteorological conditions prevailed at the time and no flight plan was filed for the 14 CFR Part 137 aerial application flight. The commercial-rated pilot, the sole occupant was not injured. The time of departure has not been determined. The pilot stated that before the flight departed the fuel gauge indicated between 55 and 60 gallons and after applying about 20 loads, the low fuel level warning light "flickered." He then started his chronometer according to the flight manual, and continued the application. About 6 minutes later he advised his ground crew to set up for refueling which would take place after the last application. While en route to refuel flying about 150-200 feet above ground level near the refueling location, he heard a drop in the engine rpm. He confirmed this by observation of the engine tachometer, released the bucket, and initiated a turn toward a clearing completing 270 degrees. He intentionally pulled collective to clear trees below and as a result during the pitch pull about 10-15 feet above ground level, the main rotor rpm was reduced. Upon touchdown the main rotor blades severed the tailboom. The helicopter then bounced forward about 10-15 feet forward of the initial touchdown point and came to rest. The pilot further stated that in the past while on the ground after fueling, the fuel probe in the fuel tank would stick and he had brought this to the attention of the maintenance department. Examination of the helicopter by FAA personnel revealed no fuel remaining in the fuel tank which was intact. Fuel was then added to the fuel tank and the engine was started and found to operate normally. The FAA inspector also noted where the side of the fuel tank was dented which was reportedly from the pilot's attempt to dislodge the fuel gauge transmitter. Postcrash testing of the fuel gauge transmitter revealed that after the fuel tank was filled with the engine not operating, then drained, the fuel gauge in the cockpit would indicate full. After contact to the side of the fuel tank, the fuel gauge indicated the correct amount and the low fuel level warning light would illuminate. The FAA inspector also stated that he reviewed the aircraft logbooks and there was no record of maintenance to the fuel gauge transmitter. Review of the flight manual revealed that when the low fuel level warning light illuminates, 15.85 gallons remain and the flight is limited to approximately 10 minutes. According to the operations manager, in the past during refueling with the engine not operating, the fuel transmitter would stick which required contact with the side of the fuel tank. He further stated that the sticking did not occur during fueling with the engine operating or when in flight.
The pilot's intentional operation of the helicopter with known deficiencies in equipment and a false indication of the fuel gauge, resulting in the total loss of engine power due to fuel exhaustion. Contributing to the accident was inadequate maintenance of the helicopter by company maintenance personnel, and unsuitable terrain encountered during the forced landing.
Source: NTSB Aviation Accident Database
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