SH-3H N613CK accident near Willow Creek, California

Probable cause

The pilot’s failure to maintain adequate power during egress from a heliwell, which resulted in collision with the heliwell and a dynamic rollover.

NTSB analysis

The pilot-in-command (PIC) of the firefighting helicopter air tanker reported that he approached the heliwell (a portable tank) by entering a final approach from the south as he had on four previous trips that day. As he lowered the snorkel into the heliwell to get water, he simultaneously made a right pedal turn to position the helicopter for a normal egress departure path. He indicated that all engine parameters were in the normal operating range, that he did not feel any unusual movements in the flight controls, and that the wind seemed to be light and variable. As the helicopter was taking on water, the second-in-command (SIC) called out the number of gallons in the tank, and the PIC released the fill switch at the planned amount. The PIC applied power and initiated a climb just as the snorkel was clearing the water. At this time, the SIC informed the PIC of a "droop" in the rotor rpm. Subsequently, the PIC stopped applying power and started to move the helicopter forward. The SIC then called out that the rotor rpm was at 98 percent. The PIC reduced the power slightly to gain rpm, but the rpm continued to drop. The PIC leveled the helicopter as it continued to descend. The left main landing gear subsequently contacted the heliwell then the uneven ground. The helicopter rolled after ground contact and came to rest on its left side. The PIC did not activate the emergency dump button, which was located on the top left side of the collective, and the SIC did not pull the emergency "T" handle to jettison the load during the accident sequence. Postaccident examinations of the engines and fuel controls found no mechanical malfunctions or failures that would have precluded normal operations.

Text from the NTSB. Open the NTSB docket for WPR09TA353 for the full record.