NTSB Identification: LAX04CA321.
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Accident occurred Friday, September 17, 2004 in Kona, HI
Probable Cause Approval Date: 12/03/2004
Aircraft: Robinson R22 Beta, registration: N22XM
Injuries: 2 Uninjured.

NTSB investigators used data provided by various entities, including, but not limited to, the Federal Aviation Administration and/or the operator and did not travel in support of this investigation to prepare this aircraft accident report.

The helicopter experienced a hard landing, resulting in the main rotor blades severing the tail boom. While the certified flight instructor (CFI) and student pilot were executing a practice autorotation, the main rotor low revolutions per minute horn began to sound. He also realized that the airspeed had decreased 10 knots below the minimum speed for autorotations. The CFI lowered the collective while pushing the carburetor heat control knob in the "off" position. As the CFI leaned forward to assess the knob position, he felt the helicopter begin to settle. With the ground approaching quickly, he configured the helicopter it in a level attitude, fearing that if he flared, the tail boom would contact the surface first. The helicopter hit the surface hard and the main rotor severed the tail boom. The CFI stated that he did not know of any mechanical malfunctions or failures with the helicopter prior to impact.

The National Transportation Safety Board determines the probable cause(s) of this accident to be:

the CFI's failure to maintain an adequate airspeed and main rotor rpm, and his improper flare, which resulted in a hard landing. A factor in the accident was the CFI's diverted attention.

Full narrative available

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