Beech Aircraft Corp B200, VH-FDG

The Australian Transport Safety Bureau did not conduct an on-scene investigation of this occurrence. The report presented below was prepared principally from information supplied to the Bureau.

REPORTED INFORMATION

At 0337 Western Standard Time on 11 April 2004, a Beech Aircraft Company Super King Air aircraft, registered VH-FDG, with one pilot, a flight nurse and one passenger on board was conducting an aeromedical flight from Paraburdoo to Albany WA. The pilot reported that, during cruise at flight level 310, the right engine surged, followed by rising Inter-Turbine Temperature. The engine was shut down and the flight diverted to Jandakot, WA.

A subsequent engineering examination by the operator's maintenance engineers revealed that the engine had been subjected to severe over-temperature damage resulting in turbine failure.

The engine was sent to the manufacturer's overhaul facility for further examination. The examination confirmed that the reported damage resulted from over-temperature conditions in the engine. The engine's fuel control unit (FCU) was removed and tested to determine if it conformed to the required fuel scheduling specifications. The testing revealed that the FCU was not metering the fuel to the appropriate schedule and that the engine may have been subject to hot starting¹ conditions and a rich acceleration² schedule. These conditions would have shortened the service life of the engine, leading to the reported failure.

¹ Hot starting refers to a higher than normal temperature reached during the engine starting cycle.
² A rich acceleration schedule indicates that that FCU was providing a higher than normal fuel flow to the engine during starting.