Pilot Experienced A “Jolt” And Suddenly The Helicopter “Dropped”

Location: Bovill, ID Accident Number: WPR21LA354
Date & Time: September 23, 2021, 15:00 Local Registration: N5334V
Aircraft: Hiller UH-12E Injuries: 1 Minor
Flight Conducted Under: Part 137: Agricultural

On September 23, 2021, about 1500 Pacific daylight time, a Hiller UH-12E helicopter, N5334V, was substantially damaged when it was involved in an accident near Bovill, Idaho. The pilot was not injured.

The helicopter was operated as a Title 14 Code of Federal Regulations Part 137 aerial application flight. The pilot reported that he had been applying dry fertilizer over trees as part of a timber company contract and had flown about 5.7 hours that day. As he was approaching the service truck to refill his bucket, about 40 ft above ground level and about 20 ft from the truck, the pilot experienced a “jolt” and suddenly the helicopter “dropped” to the sloping terrain below.

The pilot stated he had no time to react and that the helicopter didn’t turn or yaw after the “jolt.” He did recall the torque gauge indicated between 85% and 90% during the accident sequence. The pilot further stated that everything on the helicopter had involuntarily shut down before he had exited. The witness that was manning the truck reported to the pilot didn’t hear anything abnormal. He also stated that the wind was light and variable at the time of the accident.

The helicopter impacted the ground and came to rest on its side. The cabin area and windshield structure were bent and distorted. The tailboom separated near the midsection and the main rotor blades were buckled in multiple areas.

The helicopter was recovered by the operator and secured at the operator’s facility for further examination.

FMI: www.ntsb.gov