With A Speed Near Effective Translational Lift At 80% Torque, The Helicopter Suddenly Started To Bounce And Yaw

Location: Yuma, AZ Accident Number: WPR23LA107
Date & Time: February 6, 2023, 21:35 Local Registration: N36FA
Aircraft: Bell OH-58A Injuries: 1 Minor
Flight Conducted Under: Part 137: Agricultural

On February 6, 2023, about 2135 mountain standard time, a restricted category Bell OH-58A helicopter, N36FA, was substantially damaged when it was involved in an accident near Yuma, Arizona. The commercial pilot sustained minor injuries. The helicopter was operated as a Title 14 Code of Federal Regulations Part 137 agricultural aerial application flight.

The pilot reported that after the night application of chemical insecticide, he landed on the load truck and the chemical hopper was filled with 50 gallons of water. He maneuvered the helicopter to an open field in low light conditions and expelled the water to rinse out the applicator system. While he was maneuvering about 30 to 40 feet above ground level, with a speed near effective translational lift at 80% torque, the helicopter suddenly started to bounce and yaw. The pilot heard the turbine engine spool down as he held full throttle position and the engine lost all power. The pilot arrested his forward movement by raising the nose. He then leveled the helicopter and started to descend. The pilot raised the collective to control the descent, but the helicopter landed hard. Subsequently, the main rotor blade struck and severed the tail rotor driveshaft and the main rotor blade mast was damaged. The main rotor blades separated from the mast and landed about 100 feet from the helicopter. 

The helicopter was recovered to a secure location for further examination.

FMI: www.ntsb.gov