Bell OH-58A N36FA accident near Yuma, Arizona

Probable cause

A total loss of engine power for reasons that could not be determined.

NTSB analysis

The pilot of the helicopter was conducting an agricultural application flight in dark night conditions. He stated that, after completing the chemical application, he landed on the load truck and the hopper was filled with 50 gallons of water to rinse out the applicator system. The pilot departed from the load truck toward an open field about 200 yards away. The pilot stated that, while maneuvering about 40 ft above ground level when the spray tank was almost empty, the helicopter began to “bounce and tilt in all directions,” then “fish-tailed” before the engine lost total power. The pilot stated that he was unable to judge the helicopter’s height above the ground, and the helicopter subsequently landed hard, during which the main rotor blades severed the tail rotor drive shaft.

Postaccident examination of the helicopter and engine revealed no anomalies or malfunctions that would have precluded normal operation. About 5 gallons of fuel was found in the fuel tank, 1.4 gallons of which was unusable. No engine abnormalities were found during an engine run on a test stand.

Based on the available information, the reason for the loss of engine power could not be determined.

Text from the NTSB. Open the NTSB docket for WPR23LA107 for the full record.