Robinson R22 crash near Kona, HI, United States

The pilot receiving instruction was practicing an autorotation when the main rotor rpm decayed. The flight instructor took control of the helicopter and attempted to correct the low main rotor rpm. However, the helicopter landed hard in a nose high attitude, which resulted in structural damage to the tailboom. The pilot reported no preimpact mechanical malfunctions or failures with the helicopter that would have precluded normal operation.