Aviation Accident Summaries

Aviation Accident Summary SEA08LA020

Cougar, WA, USA

Aircraft #1

N831SD

Arrow Falcon Exporters OH-58+

Analysis

After lifting off from a dirt pad, the pilot maneuvered the helicopter into a seven to ten foot hover over the fertilizer bucket that was on the end of his long-line. Once centered over the bucket, the pilot began to climb straight up in a hover. As he lifted the bucket off the ground, the helicopter's nose dipped aggressively down, and the pilot became aware that the long-line was caught on the left side of the lower wire strike mechanism. The pilot attempted to put the bucket back on the ground, but the helicopter again dipped forward and to the right. As the pilot continued to attempt to maintain the position of the helicopter while he put the bucket back on the ground, it impacted a nearby Noble fir tree, and fell to the terrain below. According to the pilot and the Federal Aviation Administration Inspector who responded to the scene, there were no anomalies or malfunctions associated with the helicopter's flight controls, engine, or airframe.

Factual Information

On November 6, 2007, about 0855 Pacific standard time, an Arrow Falcon Exporters OH-58+ helicopter, N831SD, impacted a tree during long-line fertilizer operations near Cougar, Washington. The commercial pilot, who was the sole occupant of the helicopter, received minor injuries, and the helicopter, which is owned and operated by Farm and Forest Helicopter Services, sustained substantial damage. The local 14 CFR Part 137 aerial application flight, which lifted off from a dirt pad about one minute before the accident, was being operated in visual meteorological conditions. No flight plan had been filed. According to the pilot, after lifting off from the dirt pad, he maneuvered the helicopter into a seven to ten foot hover over the fertilizer bucket that was on the end of his long-line. Once centered over the bucket, the pilot began to climb straight up in a hover. As he lifted the bucket off the ground, the helicopter's nose dipped "aggressively down," and the pilot became aware that the long-line was caught on the left side of the lower wire strike mechanism. The pilot therefore attempted to put the bucket back on the ground, but the helicopter again dipped forward and to the right. As the pilot continued to attempt to maintain the position of the helicopter while he put the bucket back on the ground, it impacted a nearby Noble Fir tree, and fell to the terrain below. The helicopter came to rest on its right side. According to the pilot and the Federal Aviation Administration Inspector who responded to the scene, there were no anomalies or malfunctions associated with the helicopter's flight controls, engine, or airframe. The pilot submitted a written statement describing the sequence of events, but he did not submit an NTSB Form 6120.1/2.

Probable Cause and Findings

The pilot's failure to maintain clearance from a nearby tree while performing a hover-climb. Factors include his failure to maintain clearance from his long-line cable, and his likely diverted attention to the entanglement of the cable on the helicopter's wire strike mechanism.

 

Source: NTSB Aviation Accident Database

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