Accident Overview
A helicopter was substantially damaged during a forced landing after experiencing a total loss of engine power while climbing out. The pilot performed an autorotation into a cornfield. During the landing, the pilot could not maintain directional control due to soft ground conditions, causing the helicopter to slide approximately 100 feet and turn about 190 degrees to the left. The main rotor and tail rotor contacted the ground, but the helicopter came to rest upright.
Pilot's Account
The pilot reported that during the previous shutdown, the engine did not sound normal. A postflight inspection revealed the engine oil quantity was six quarts low. The pilot added six quarts of oil before restarting the engine. After startup, the pilot walked around the helicopter and noticed smoke emanating from the engine compartment and heard the engine misfiring. The pilot brought the helicopter into a hover to test whether the engine would sustain power. After hovering briefly, the pilot departed on the accident flight. During climb out, the engine experienced a total loss of power, prompting the autorotation.
Witness Report
A witness observed the helicopter on the ramp with the engine running. The witness reported smoke coming from the engine compartment and the engine misfiring at idle power. The witness stated that the helicopter then departed with smoke trailing from the helicopter.
Engine Examination
An inspection of the engine revealed that the number two cylinder connecting rod had separated from the crankshaft. The rod cap, cap bolts, and bearing material were not recovered. The number two crankshaft journal surface was smooth, shiny, and did not show any evidence of heat discoloration.