On September 21, 1994, at 1300 hours mountain standard time, an Australian registered Robinson R-22, VHCOS, collided with the terrain and rolled over while executing a precautionary landing near Benson, Arizona. The pilot was conducting a visual flight rules ferry flight to Grand Prairie, Texas. The helicopter, operated by HeliJet, Brisbane, Australia, sustained substantial damage. Neither the certificated commercial pilot nor his passenger were injured. Visual meteorological conditions prevailed. The flight departed Goodyear Airport, Goodyear, Arizona, at 1100 hours. The pilot reported to National Transportation Safety Board investigators that he was delivering the helicopter to the operator from Torrance, California. The pilot was conducting the second leg of the flight to Grand Prairie. When the flight was between 500 and 700 feet above the ground, the pilot felt a "slight vibration" on the pedals. The vibration felt like the helicopter struck a small bird. He turned the helicopter 180 degrees toward an open area and began a precautionary landing. While on final approach to the landing area, at 50 feet above the ground, the pilot noticed the landing area was covered with high vegetation, and began to go-around. The helicopter was at 20 knots indicated airspeed, and the main rotor rpm was at the "bottom of the green arc." During the go-around, the rpm continued to decay and the helicopter began to settle. The pilot executed a right pedal turn and the skid became entangled with the high vegetation. The low rotor rpm horn sounded just before impact. The helicopter rolled over on touchdown. A Safety Board investigator from the Central Regional Office examined the helicopter at Grand Prairie, Texas. The investigator reported no evidence of a flight control or any other preexisting malfunction or failure. He also said that there was no evidence that the main rotor blades struck a bird.