Primary finding
Probable cause
The in-flight separation of the stabilizer bar tube.
Investigator assessment
Analysis narrative
The 4,900-hour commercial pilot was maneuvering the single engine helicopter during a photo mission at approximately 1,500 feet mean sea level (MSL) at about 45 knots when he reported hearing a loud bang and a nearly simultaneous erratic movement of the cyclic control. The pilot immediately started looking for a place to land the helicopter. The pilot increased the airspeed and headed for a suitable landing area. On final approach to a vacant football field, the helicopter began to spin as the airspeed began to decay. The pilot then elected to enter an autorotation and landed upright with no further damage. The pilot and his passenger were not injured. An FAA inspector that traveled to the accident site reported that one stabilizer tube from the mast control stabilizer bar assembly had separated from the main rotor system and made the tail rotor assembly after it separated from the helicopter. Approximately 3 inches of one tail rotor blade was found fractured and the 90 degree tail rotor gear box separated from the tail rotor drive shaft. At the time of the accident the winds were reported from 360 degrees at 22 knots, gusting to 29 knots.
Source record
Factual narrative
The 4,900-hour commercial pilot was maneuvering the single engine helicopter during a photo mission at approximately 1,500 feet mean sea level (MSL) at about 45 knots when he reported hearing a loud bang and a nearly simultaneous erratic movement of the cyclic control. The pilot immediately started looking for a place to land the helicopter. The pilot increased the airspeed and headed for a suitable landing area. On final approach to a vacant football field, the helicopter began to spin as the airspeed began to decay. The pilot then elected to enter an autorotation and landed upright with no further damage. The pilot and his passenger were not injured. An FAA inspector that traveled to the accident site reported that one stabilizer tube from the mast control stabilizer bar assembly had separated from the main rotor system and made the tail rotor assembly after it separated from the helicopter. Approximately 3 inches of one tail rotor blade was found fractured and the 90 degree tail rotor gear box separated from the tail rotor drive shaft. At the time of the accident the winds were reported from 360 degrees at 22 knots, gusting to 29 knots.