CEN18LA260

The commercial helicopter pilot indicated that, about 10 minutes after takeoff, while making a turn during an aerial application flight, he noticed the low fuel pressure light illuminate; the fuel pressure gage indicated 0 psi, and the fuel quantity gage indicated 15 gallons. The engine subsequently lost total power, and the pilot performed an autorotation in preparation for a forced landing, during which the helicopter nosed over and sustained damage to the main and tail rotors. Postaccident examination of the helicopter revealed that the fuel quantity gage read 4 gallons, and the fuel tank contained about 9.5 gallons of fuel. Both fuel boost pumps tested normally. Examination of the airframe and engine revealed no evidence of mechanical malfunctions or failures that would have precluded normal operation. The helicopter's flight manual stated to land as soon as practical when fuel quantity was less than 20 gallons and contained a warning that uncoordinated turns and maneuvers were to be avoided with a fuel quantity of less than 20 gallons. The manual also stated that, due to possible fuel sloshing in unusual attitudes or out-of-trim conditions and one or both fuel boost pumps inoperative, the unusable fuel was 10 gallons. The turn during spray operations with less than 20 gallons of fuel likely caused the fuel to unport, allowing air into the fuel line. This resulted in a total loss of engine power due to fuel starvation. The pilot did not ensure that adequate fuel was on board for the maneuvering flight.

On July 6, 2018, about 1715 central daylight time, a Bell 206B helicopter, N224KM, was substantially damaged during a forced landing near Bentley, Illinois. The pilot was not injured. The helicopter was registered to and operated by Woodley Aerial Leasing LLC under the provisions of Title 14 Code of Federal Regulations Part 137 as an aerial application flight. Day visual meteorological conditions prevailed for the local flight, which departed about 1705 from a load truck near Bentley, Illinois. According to the pilot, he departed the load truck and flew about 1.5 miles east to an application area. While making a turn, he noticed the low fuel pressure light illuminate. After initiating a climb, he noticed the fuel quantity gage indicated 15 gallons and the fuel pressure gage indicated zero psi. The pilot initiated an autorotation in preparation for a forced landing. During touchdown, the helicopter nosed over, which damaged the main and tail rotors. Examination of the helicopter revealed the fuel quantity gage read about 4 gallons. About 1.5 quarts of fuel were drained from the airframe and filter sumps, with no anomalies observed. The fuel valve switch was found in the on position. The forward and aft fuel boost pumps were tested individually, with normal pressures observed. The fuel tank was drained, revealing that about 9.5 gallons of total fuel were present in the tank. Examination of the airframe and engine revealed no evidence of mechanical malfunctions or failures that would have precluded normal flight operations. The helicopter's flight manual stated to land as soon as practical when fuel quantity was less than 20 gallons. The flight manual contained a warning that uncoordinated turns and maneuvers were to be avoided with a fuel quantity of less than 20 gallons and also stated that due to possible fuel sloshing in unusual attitudes or out of trim conditions and one or both fuel boost pumps inoperative, unusable fuel was 10 gallons.