Accident Details
During a practice 180-degree autorotation, a helicopter landed hard, bounced, spun around, struck the ground again, and rolled over onto its right side. The accident occurred in the context of routine training maneuvers.
Pilot Statements
The pilot-undergoing-instruction (PUI) reported that after rolling out onto final approach at 400 feet AGL, he leveled the helicopter, rolled in throttle, and initiated a flare at about 70 feet AGL. At approximately 50 feet AGL, he leveled the flare because the helicopter "did not feel like it was building energy" and the flare seemed less effective. Rotor rpm was at 100 percent. The PUI stated there appeared to be insufficient engine power to recover, so he leveled the aircraft and raised the collective. The low rotor horn sounded shortly thereafter.
Procedures
The Los Angeles City Fire Department "flare autorotations" procedure describes that at approximately 75 feet, the pilot should begin a smooth cyclic flare, leveling the ship with quick but smooth cyclic movement, with expected altitude loss but leveling by 10 feet.
Engine and Fuel Control Tests
An engine teardown was conducted with no anomalies found. The fuel control and governor were bench tested and performed to specifications.