Investigation number
198903791
Occurrence date
Location
Delta Downs Station
Report release date
Report status
Final
Investigation type
Occurrence Investigation
Investigation status
Completed
Occurrence class
Accident
Highest injury level
Serious

Whilst conducting mustering operations at low speed and altitude over trees, the engine began to run rough. The helicopter was unable to sustain continued flight and the pilot elected to land. During the landing the rotor blades struck trees and the helicopter landed heavily coming to rest on its side. The pilot was able to crawl to safety after switching the magnetos off, but he was unable to reach the fuel mixture control. The engine subsequently oversped to destruction. The investigations found that the left magneto had suffered an internal failure. The bush supporting the distributor rotor gear had become loose in its housing, allowing the rotor to become mis-timed. During the impact sequence, the magneto earthing wires were fractured which allowed the engine to continue to run despite the pilot switching off the magnetos.

Aircraft Details
Manufacturer
Bell Helicopter Co
Model
47
Registration
VH-SXO
Serial number
7811
Operation type
Aerial Work
Sector
Helicopter
Departure point
Delta Downs Station QLD
Departure time
0945
Destination
Delta Downs Station QLD
Damage
Substantial