Croman Corporation SH-3H N611CK accident near Covelo, California

Probable cause

The pilot’s failure to maintain clearance from a tree during an aerial firefighting flight.

NTSB analysis

The helicopter was involved in firefighting operations. The pilot flying was in the left seat, and the senior pilot was in the right seat. The pilot completed numerous water drops on the fire during a 2-hour period. The helicopter was making its second drop in an area of steep terrain, which was about 1,000 feet lower in elevation than the lake the pilots were using for a water source. Due to the smoke, the visibility was about 1/2 mile. All five main rotor blades made contact with a snag (typically the remnants of a tree such as the trunk and/or main branches without most of its foliage), and were substantially damaged; the operator pointed out that the snag was similar in color to the smoke. The senior pilot took control of the helicopter, climbed, and made an uneventful landing near the fill point.

Text from the NTSB. Open the NTSB docket for WPR12CA387 for the full record.