Aviation safety investigations & reports

Partial power loss – Gippsland Aeronautics GA8, VH-WOV, Kununurra airport, WA, 28 April 2012

Investigation number:
Status: Completed
Investigation completed


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At about 0815 Western Standard Time on 28 April 2012, a Gippsland Aeronautics GA8-TC 320 aircraft, registered VH-WOV, took off from runway 12 at Kununurra airport, Western Australia, for a sightseeing flight over the Bungle Bungle ranges. On board were the pilot and six passengers.

Despite the application of full throttle during the takeoff, the engine manifold pressure was lower than expected. The manifold pressure decreased further soon after the aircraft became airborne, to the point that level flight could not be maintained. The pilot initially prepared for a forced landing, but after finding that sufficient power was available to remain airborne, and assessing the surface of the selected field as unsuitable, the pilot elected to return to the departure airport. The pilot landed on the grass surface of the airport adjacent to the parallel taxiway, with no injuries reported and no damage to the aircraft. The low and decreasing manifold pressure was the result of an engine turbocharger system malfunction.

This incident highlights the importance of understanding the complexities of engine turbocharger systems. A turbocharger system malfunction may result in unpredictable engine power and aircraft performance. Furthermore, a turbocharger system malfunction does not necessarily mean that the engine will behave like a normally aspirated engine. Although this incident was the result of a turbocharger system malfunction, pilots are reminded that abnormal manifold pressure indications may be symptomatic of a serious problem, such as an engine exhaust system leak.

This incident also highlights the importance of pre-flight preparation. Self-briefing may help pilots respond to abnormal takeoff indications more effectively, and help manage the influence of perceived pressure when confronted with a time-critical decision.

Aviation Short Investigation Bulletin - Issue 12

Download Final Report
[Download  PDF: 181KB]
Alternate: [Download  DOC: 3.31MB]
General details
Date: 28 April 2012   Investigation status: Completed  
Time: 0815 WST   Investigation level: Short - click for an explanation of investigation levels  
Location   (show map): Kununurra airport    
State: Western Australia   Occurrence type: Engine failure or malfunction  
Release date: 29 October 2012   Occurrence category: Serious Incident  
Report status: Final   Highest injury level: None  

Aircraft details

Aircraft details
Aircraft manufacturer Gippsland Aeronautics Pty Ltd  
Aircraft model GA8  
Aircraft registration VH-WOV  
Serial number GA8-TC 320-09-145  
Type of operation Charter  
Damage to aircraft Nil  
Departure point Kununurra, WA  
Destination Kununurra, WA  
Last update 14 November 2018