What happened
During a demonstration of autorotations, a flight instructor with 10,120 hours of experience was operating a helicopter when the aircraft experienced a hard landing. The impact caused the helicopter to bounce back into the air, at which point the main rotor blades struck the tail boom. As the aircraft began to rotate, the pilot reduced the throttle, and the helicopter subsequently landed upright in a field.
At the time of the accident, the weather near the site was reported as having winds from 040 degrees at 6 knots, with visibility of 10 statute miles and clear skies. The temperature was 84 degrees Fahrenheit with a dew point of 70 degrees Fahrenheit, and an altimeter setting of 29.94 inches of Mercury. The pilot noted that following the accident, the wind had shifted to 350 degrees at approximately 10 knots.
Findings
An investigation determined the density altitude at the time of the event was 2,485 feet mean sea level.