Mt Nebo Aviation

Beechcraft 60 Duke

During climb to cruise the pilot reported a power loss on one engine and received vectors for a return to the departure airport. The pilot was subsequently cleared for the VOR-A approach and reported intercepting the inbound radial. The impact site was right of the inbound radial and short of the extended runway centerline. Weather at the airport was VFR. Post impact fire damaged the airplane. The left engine propeller was in the feather position. Visual and metallurgical examination confirmed the turbocharger shaft separated due to fatigue. The shaft contained chromium. The aircraft overhaul manual states that 'chrome plating...restoration of the shaft...are not permitted.' Metallographics revealed a microstructure of grey iron (automotive application) in the center housing. The turbocharger was overhauled and installed on the left engine in october 1989. All three occupants were killed.