Hiller UH-12E N945HA accident near Cokato, Minnesota

Probable cause

The pilot did not visually identify and maintain clearance with the power lines, and the pilot's inability to maintain control of the helicopter once it contacted the power lines. Factors associated with the accident were the low altitude operations being conducted and the power lines.

NTSB analysis

The pilot reported he made three passes over the fields that he was going to spray. He stated he noticed a power line pole that had a transformer cover on it and what appeared to be a wire covering running up the pole. This led the pilot to believe that the power lines in the area were buried. The pilot then landed and loaded the chemicals. He stated that after taking off with the load, he flew one more pass to look for power lines and still did not see any. He stated that during the first swath run, the helicopter contacted power lines. The helicopter initially pitched nose up and to the right. The pilot stated he pushed the nose down and to the left, but the power lines wrapped around the control tubes and tail rotor. The helicopter then entered a descending spin. The pilot stated he pulled back to flatten the descent just prior to the helicopter contacting the ground.

Text from the NTSB. Open the NTSB docket for CHI08CA252 for the full record.