Accident Overview
On July 6, 2018, at approximately 1715 central daylight time, a Bell 206B helicopter, registration N224KM, sustained substantial damage during a forced landing near Bentley, Illinois. The helicopter was operated by Woodley Aerial Leasing LLC under Title 14 Code of Federal Regulations Part 137 as an aerial application flight. The pilot reported no injuries. Day visual meteorological conditions prevailed for the local flight, which had departed from a load truck near Bentley at about 1705.
Pilot Report
According to the pilot, after departing the load truck, he flew approximately 1.5 miles east to an application area. While making a turn, the low fuel pressure light illuminated. Initiating a climb, he observed that the fuel quantity gauge indicated 15 gallons and the fuel pressure gauge indicated zero psi. The pilot then initiated an autorotation in preparation for a forced landing. During touchdown, the helicopter nosed over, resulting in damage to the main rotor and tail rotor.
Examination Findings
Post-accident examination revealed that the fuel quantity gauge read about 4 gallons. Approximately 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. Both the forward and aft fuel boost pumps were tested individually and produced normal pressures. The fuel tank was drained, revealing a total of about 9.5 gallons of fuel present. Examination of the airframe and engine found no evidence of mechanical malfunctions or failures that would have precluded normal flight operations.
Flight Manual Considerations
The helicopter's flight manual specified that the pilot should land as soon as practical when fuel quantity is less than 20 gallons. Additionally, the manual contained a warning to avoid uncoordinated turns and maneuvers with a fuel quantity of less than 20 gallons. It also stated that due to possible fuel sloshing in unusual attitudes or out-of-trim conditions, and with one or both fuel boost pumps inoperative, the unusable fuel amount was 10 gallons.