Amateur-built BARNETT J4B N35JB accident near Sheridan, California

Probable cause

A loss of engine power due to carburetor icing as a result of the pilot's failure to use carburetor heat.

NTSB analysis

While in cruise flight, the gyroplane experienced a loss of engine power and the pilot initiated a forced landing onto a highway. After an uneventful landing, the pilot steered the gyroplane off the road to avoid a vehicle, and the gyroplane encountered a ditch and rolled onto its right side. The vertical stabilizer and rudder were bent and wrinkled, and the rotor head was destroyed. Postaccident examination of the engine by the gyroplane's owner revealed no evidence of mechanical failures or malfunctions. The owner stated that the high humidity and the pilot's description of the power loss indicated carburetor icing had occurred. The owner further stated that the gyroplane was equipped with carburetor heat; however, the pilot did not use it. Review of the carburetor ice probability chart revealed that the temperature and dew point at the time of the accident were conducive to icing conditions at cruise power and serious icing conditions at glide power.

Text from the NTSB. Open the NTSB docket for WPR09LA161 for the full record.