Aviation Accident Summaries

Aviation Accident Summary SEA99LA038

SHELTON, WA, USA

Aircraft #1

N194AC

Sikorsky S-64E

Analysis

The pilot of the aero-logging helicopter had lowered a multiple-log load onto the landing site, hit the release switch to release the two choker cables, and then began to move away from the area. One of the choker lines momentarily failed to release, resulting in one end of one of the logs lifting into the air and then falling back to the ground. One of the ground crew members entered the landing area after the logs were initially lowered to the ground, but prior to the release of the second cable. When the end of the log lifted into the air and fell back to the ground, it fell on the crew member, inflicting fatal injuries. It was the opinion of some of the other crew members that the victim never noticed that the second cable had not yet released or that the end of the log was being lifted back into the air. According to Washington Administrative Code, Chapter 296-54, 'Logs shall be laid on the ground and the helicopter will be completely free of the choker()s) before workers approach the logs.'

Factual Information

On March 2, 1999, approximately 1120 Pacific standard time, a log being positioned by an aero-logging Sikorsky S-64E helicopter, N194AC, hit a ground crew member when a choker line momentarily failed to release from the long-line. The helicopter, which was being operated near Shelton, Washington, by Erickson Air Crane under 14 CFR Part 133, was not damaged, nor was its crew injured. The ground crew member received fatal injuries. The helicopter, which was bringing logs into the landing (collection point), was being operated under VFR conditions at the time of the accident. According to the aircrew, as the pilot-in-command started to move the aircraft away from the landing after lowering a multiple-log load to the ground, one of the two choker lines momentarily failed to separate from the long-line release mechanism. This resulted in the one end of one of the logs lifting back into the air and then falling to the ground. According to witnesses, one member of the ground crew, who was positioned separately from the others, ran into the collection area immediately after the logs initially touched the ground. When one end of the subject log lifted into the air and dropped back to the ground, it landed on the crew member, inflicting fatal injuries. An inspection of the release mechanism did not reveal why the line failed to immediately release. According to other ground crew members, a representative of Erickson Air Crane, and the Washington Safety Compliance Inspector who responded to the scene, occasionally a choker line will momentarily hang up during the release sequence. It could not be determined why the crew member had entered the landing prior to both choker lines separating from the release, but some of the other ground crew members felt that the victim had simply failed to notice that the second choker line had not yet released. The witnesses also felt that since the victim ran into the landing with his head down, he probably did not see the end of the log being lifted back into the air. During the investigation, it was determined that the victim had worked as a member of the aero-logging ground crew for the same company for about the last seven years (except for seasonal layoffs). During those years, he had performed duties both at the location where the logs where lifted out after being felled, and at the landings where the logs were decked (stacked). It was also noted that Washington Administrative Code (WAC), Chapter 296-54 (Safety Standards for Logging Operation), Section 296-54-559, Item 16, states that "Logs shall be laid on the ground and the helicopters will be completely free of the choker(s)before workers approach the logs."

Probable Cause and Findings

The failure of the victim to follow the procedure that required him to make sure that all choker lines had separated from the helicopter's release mechanism prior to entering the landing (collection area).

 

Source: NTSB Aviation Accident Database

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