Accident Overview
On October 10, 2008, at approximately 1030 Pacific daylight time, a Bell 206B helicopter, registration N206CH, impacted terrain while maneuvering in hilly terrain near Cougar, Washington. The commercial pilot sustained serious injuries, and the helicopter, owned and operated by Northwest Helicopters, incurred substantial damage. The flight was conducted under 14 Code of Federal Regulations (CFR) Part 133 as a rotorcraft external load operation. It had departed Olympia, Washington, about one hour and fifteen minutes prior to the accident and was operating in visual meteorological conditions. A company visual flight rules (VFR) flight plan had been filed.
Sequence of Events
According to witnesses on the ground, the helicopter was hauling tree limbs uphill to a central pickup point. The load, attached to a 60-foot cable, became entangled in trees over which the helicopter was flying. The pilot reported that when the load was approximately 20 feet above the ground, the helicopter experienced a rapid 15- to 20-degree roll to the right, then quickly returned to a level attitude. At that moment, the pilot looked outside to check if the load was tangled, but later could not recall what he observed. His next memory was looking forward and slightly uphill, noting that he could not move the cyclic laterally to the left from its position about 10 degrees right of center. He continued trying to fly uphill toward a dirt road but had little control over the helicopter. As he neared the road, the low-rotor horn activated. Shortly thereafter, at an altitude he estimated as 20 to 40 feet above the terrain, the helicopter yawed to the right and pitched nose-down. The pilot, anticipating an imminent ground impact, rolled off the throttle to at least the idle position.
Witness Accounts
Witnesses reported that the helicopter impacted the terrain near the bottom of a steep, tree-covered ravine. The long-line had been released from the helicopter prior to impact, although the pilot did not recall doing so. The long-line was found approximately 75 feet from the crash site, with the end attached to the helicopter lying closest to the site.
Post-Accident Inspection
An inspector from the Federal Aviation Administration (FAA) Portland Flight Standards District Office (FSDO) responded to the accident site. The inspector interviewed witnesses and conducted an on-site inspection of the helicopter. The helicopter was subsequently recovered to the operator's hangar, where further FAA inspection took place. Neither the on-site nor follow-up inspection revealed any evidence of airframe, engine, or flight control anomalies that would have contributed to the accident sequence.