Bell 47G crash near Plymouth, MI, United States

The helicopter experienced a total loss of engine power about 2 miles northeast of the departure airport. The pilot then performed an autorotation onto a grass area near interstate 275. The helicopter sustained substantial damage, which included damage to the main rotor blades and left side of the fuselage. The pilot was uninjured. Examination of the helicopter revealed no anomalies that would have precluded normal operation and the installation of a carburetor temperature gauge. The pilot stated that he did not use carburetor heat during or after the takeoff from the departure airport. Weather conditions at the time winds 290 degrees at 9 knots, gusts to 17 knots, 10 statute miles, 2,900 feet overcast, temperature 23 degrees Celsius, dew point 17 degrees Celsius, and altimeter 30.00 inches. According to the Carburetor Icing Probability Chart, the conditions were conducive to serious icing at glide power.