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.