Aircraft Accident/Incident Report

Tranquility, California 93668
Wednesday, July 29, 1998 22:48 PDT

The purpose of the flight was to air-evac two victims of an automobile crash on a local highway. Responding sheriff and fire ground units to the traffic accident set up a landing zone in a farmyard. The pilot and ground witnesses described the landing zone as a confined dirt lot roughly 150 feet square surrounded by silos, power lines, trees, and buildings. Emergency vehicles were using their headlights to illuminate the landing area and a fire person was functioning as a ground guide for the landing. After making three high recon orbits around the landing site the pilot made the landing approach, and, as the helicopter neared touchdown it was 'engulfed in a large cloud of dust very quickly' to the point where visual contact with the ground was lost. The pilot said he tried to focus on the ground through the chin bubble window and added collective in an attempt to climb out of the dust; however, the right wheel touched down and the helicopter rolled over. A deputy sheriff 60 feet from the landing spot said that as the helicopter descended from 15 to 3 feet above the ground a dust cloud began to form, which thickened until the only thing he could see of the aircraft was the landing lights and the front wheel. The helicopter suddenly dropped to the ground and bounced on its wheels and then the deputy heard the engine noise increase in pitch and sound. It rose about 3 feet off the ground, drifted to the right about 6 feet, and then rolled over. The moon was located 10.9 degrees above the western horizon with only 38 percent of the disk illuminated.

The pilot's delayed initiation of a go-around when the severity of the dust condition first became apparent. Contributing factors were dark night conditions and the obscuration from the dust.