NTSB Identification: MIA04GA117.
The docket is stored in the Docket Management System (DMS). Please contact Records Management Division
Accident occurred Wednesday, August 04, 2004 in Bunnell, FL
Probable Cause Approval Date: 08/29/2006
Aircraft: Bell 47G-5, registration: N232MC
Injuries: 1 Fatal.
: NTSB investigators either traveled in support of this investigation or conducted a significant amount of investigative work without any travel, and used data obtained from various sources to prepare this public aircraft accident report.
The aerial application flight departed at about 1030, and search efforts were initiated after it was determined to be 45 minutes overdue. The wreckage was located at about 1300 in a marshy and grassy area. An examination of the engine yielded no evidence of pre-impact machanical failure or malfunction, and an examination of the airframe revealed evidence consistent with power being present on the rotor system at the time of impact. The helicopter frame aft of the cabin was connected and displayed little damage, but the short shaft had become detached. The universal joint, tail rotor drive yoke, tail rotor guard fork assembly, and their attachment points on the aft end of the tailboom exhibited fractures and mechanical damage consistent with overload. Further analysis revealed that the characteristics of the fractures and mechanical damage were consistent with overload from the tail rotor drive yoke, tube and gearbox pivoting up and forward around the two attachment lugs at the top side of the aft end of the tailboom. An area where paint had been scrapped off was noted along the bottom of the tail rotor guard. Witnesses reported two tail strikes with the aircraft prior to the accident flight. One witness reported seeing the helicopter hit the tail on the ground during landing earlier on the day of the accident. Another witness reported seeing the tail boom come in contact with the ground during landing a day earlier. The site where the helicopter had reportedly hit its tail on the day prior to the accident was examined and a rounded impression was observed in a sodden area that was consistent with the size and shape of the helicopter's tail rotor guard.
The National Transportation Safety Board determines the probable cause(s) of this accident to be: The pilot's continued flights and inadequate inspections after repeated tail rotor guard ground strikes due to improper flaring, which resulted in an in-flight failure of tail rotor drive shaft components, a loss of control, and the helicopter crash. Full narrative available
Index for Aug2004 | Index of months