Aviation Accident Summaries

Aviation Accident Summary CEN18LA025

Larchwood, IA, USA

Aircraft #1

N7085M

ROBINSON HELICOPTER R44

Analysis

The commercial pilot was conducting a helicopter flight to assist with herding cattle that had gotten loose. According to multiple witnesses on the ground, the helicopter impacted powerlines and then terrain. Video of the accident showed the helicopter facing away from the powerlines at the time of the collision with the powerlines. A postaccident examination of the airframe and engine revealed no mechanical anomalies that would have precluded normal operation at the time of the accident. The witnesses on the ground indicated that there was unlimited visibility and no precipitation at the time of the accident. Thus, the pilot was likely focused on the cattle and lost situational awareness regarding the helicopter's proximity to the powerlines, which resulted in the collision with the powerlines and terrain.

Factual Information

On November 6, 2017, about 1310 central standard time, a Robinson Helicopter R44 helicopter, N7085M, was substantially damaged when it impacted powerlines and then terrain 4.5 miles south of Larchwood, Iowa. The commercial pilot and passenger sustained serious injuries. The aerial observation flight was conducted under the provisions of 14 Code of Federal Regulations Part 91. Visual meteorological conditions prevailed and no Federal Aviation Administration (FAA) flight plan had been filed for the flight. The local flight departed about 1300.According to the passenger and witnesses on the ground, the helicopter was assisting in locating and herding 300 cattle that were loose in the area. The helicopter was assisting the ground team to push the cattle towards an open gate directly beneath powerlines. Witnesses on the ground observed the helicopter hovering and as it started to turn, the "tail" of the helicopter hit the powerlines. The helicopter descended to the ground and came to rest on its right side in a corn field. Several witnesses and the passenger stated that the helicopter looked and sounded normal prior to the impact. A video of the accident taken by another witness on the ground showed the helicopter maneuvering near the powerlines, with the nose of the helicopter facing away from the powerlines. The tail of the helicopter impacted the powerlines, followed by the main rotor blades. The helicopter rotated once before impacting the ground. According to a FAA inspector who responded to the accident, the tailboom separated from the fuselage and both main rotors were substantially damaged. An examination of the helicopter, engine, and remaining systems revealed no mechanical anomalies that would have precluded normal operations. An official weather observation taken 18 miles northwest of the accident site reported the weather as wind 060° at 7 knots, visibility 1.5 miles in light snow, overcast skies at 2,300 ft above ground level, temperature -1° C, dewpoint temperature -4°C, and an altimeter of 30.26 inches of mercury. The witnesses on the ground at the accident site characterized the weather as overcast, windy, unlimited visibility, and no precipitation. At the writing of this report, the pilot had no recollection of the accident or the events that led up to the accident.

Probable Cause and Findings

The pilot's loss of situational awareness, which resulted in his failure to maintain adequate clearance from powerlines.

 

Source: NTSB Aviation Accident Database

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