Jump to Content
Download Final Report
[ Download PDF: 22KB]

The pilot reported that while he was hovering the helicopter at about 25 feet agl, the engine suddenly lost power. He placed the helicopter in an autorotation but maintained the throttle setting that had been set while the aircraft was hovering. Just as the skids were about to contact the bushes, the engine momentarily regained power. The helicopter impacted the ground on its right hand side and fire broke out. Both the occupants escaped from the helicopter before it was destroyed by fire. An examination of the engine revealed that both valves in one cylinder had been striking the top of the piston, and the inlet valve was badly chipped. It was likely that when the inlet valve failed, a flashback occurred in the induction system, resulting in a complete loss of engine power. The engine regained power momentarily when the mixture build-up again reached a combustible level. Had the pilot closed the throttle when the engine initially failed, the sudden power surge should not have affected his ability to control the autorotation.

Download Final Report
[ Download PDF: 22KB]
General details
Date: 09 October 1985 Investigation status: Completed 
Time: 1405  
Location:Cape Portland Investigation type: Occurrence Investigation 
State: Tasmania  
Release date: 17 April 1986  
Report status: Final Occurrence category: Accident 
 Highest injury level: None 
Aircraft details
Aircraft manufacturer: Bell Helicopter Co 
Aircraft model: 206 
Aircraft registration: VH-AGL 
Type of operation: Aerial Work 
Sector: Helicopter 
Damage to aircraft: Destroyed 
Departure point:9km South of Cape Portland TAS
Departure time:1405
Destination:Rushy Lagoon Homestead TAS
Share this page Provide feedback on this investigation