Aviation safety investigations & reports

Total power loss, Talbot Bay, Western Australia, 25 September 2008, VH-NSH, Bell Helicopter Co 407

Investigation number:
AO-2008-067
Status: Completed
Investigation completed

Summary

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On 25 September 2008, a Bell Helicopter Co 407 helicopter, registered VH-NSH, with a pilot and six passengers onboard, lifted off from the helideck of the cruise ship True North on a 45-minute tourist flight. As the pilot moved the helicopter clear of the right of the ship, and at a height of about 10 m above the surface of the sea, a loud bang was heard followed by a total power loss. The helicopter rapidly descended to the water, where it rolled onto its side before inverting.

Despite two of the occupants, one of whom was unconscious, requiring assistance to exit the partially-submerged aircraft, all of the occupants survived the accident. Sometime later, the helicopter sank.

The investigation found that there had been a 'burst' failure of the engine outer combustion case as a result of ongoing high-cycle fatigue cracking during normal engine operation.

As a result of this occurrence, the engine manufacturer conducted a computerised analysis of the design of the combustion case in an effort to more effectively address the relevant areas of high stress. In response to this, and a similar failure in another helicopter 2 weeks earlier, the Civil Aviation Safety Authority released an Airworthiness Bulletin highlighting the circumstances of the occurrence to Australian helicopter operators.

The operator of the helicopter has also advised its intention to change a number of the operational procedures employed during shipborne helicopter operations to better ensure passenger safety.

Download Final Report
[Download  PDF: 3.02MB]
 
 
 
General details
Date: 25 September 2008   Investigation status: Completed  
Time: 0840 WST   Investigation level: Complex - click for an explanation of investigation levels  
Location   (show map): Talbot Bay    
State: Western Australia   Occurrence type: Engine failure or malfunction  
Release date: 28 June 2010   Occurrence category: Accident  
Report status: Final   Highest injury level: Minor  

Aircraft details

Aircraft details
Aircraft manufacturer Bell Helicopter Co  
Aircraft model 407  
Aircraft registration VH-NSH  
Serial number 53376  
Type of operation Charter  
Sector Helicopter  
Damage to aircraft Substantial  
Departure point MV True North, WA  
Destination MV True North, WA  
Last update 14 November 2018