NTSB Factual Report

On August 7, 2018, about 1000 Pacific daylight time, a Bell 206B helicopter, N607RA, struck the ground during an agricultural spray run near Basin City Washington. The commercial pilot received minor injuries, and the helicopter was destroyed by a post-impact fire. The helicopter was registered to Ranger Aviation Leasing, and operated by Northwind Aviation as a Title 14 Code of Federal Regulations Part 137 aerial application flight. Visual meteorological conditions existed at the time of the accident. The flight originated from a landing zone near the accident site.

The flight was a "rinse load" intended to clean the chemical hopper with a load of water. According to the pilot, he took off from the loading spot located on the southwest side of the field, with 60 gallons of clean water and about 25 gallons of fuel. He sprayed a portion of the north end of the field for about 3 to 4 seconds, turned off the spray, and proceeded to the east end of the field. He entered the field at a speed of about 50 to 55 mph and sprayed. He then turned off spray, and climbed to gain some altitude. When the helicopter was approximately midfield, at a speed of about 50 mph and "about power pole height," the pilot applied left tail rotor pedal and slightly lowered the collective control, in order to assist him in looking to his left to view his spray pattern. "Immediately after" those control inputs, the helicopter yawed quickly to the left, and began "shaking." The pilot pulled up on the collective control and applied right pedal to stop the left yaw. The helicopter continued to "shudder," and the pilot noticed that the helicopter was at a low airspeed and descending. He attempted to regain airspeed, and when the helicopter was about 5 to 10 ft above the ground, he attempted to level the helicopter in pitch before the skids contacted the ground. About that time the pilot observed that the torque gauge was reading about 108 to 110%.

The helicopter struck the ground hard, and fire erupted about 1 second later. The pilot exited the helicopter, but then reached in to close the throttle and turn the fuel valve off. He retrieved his mobile telephone and then moved away from the helicopter. The pilot estimated that from the time he climbed the helicopter until the accident was about 10 to 15 seconds.

The "loader" arrived on scene in the water truck within about 10 minutes of the accident. He and the pilot attempted to extinguish the fire, but were unsuccessful.

The wreckage was recovered to a secure facility for subsequent examination.