What happened
During a ferry flight intended to transport an aircraft to a facility for landing gear servicing, the pilot experienced a significant loss of power from the left engine. The aircraft was operating with its landing gear in the extended position, a state necessitated by a previous emergency gear extension procedure that required ground servicing to retract. While en route, the pilot reported difficulty feathering the left engine and noted an inability to maintain altitude. Witnesses observed the aircraft type flying at a low altitude with the wheels down before it entered a steep left bank. The plane subsequently struck trees and a fence, resulting in a post-impact fire that left the aircraft inverted on a road.
Findings
An investigation of the left engine revealed a hole in the right crankcase near the #3 cylinder attachment point. Detailed disassembly showed that the #3 connecting rod had separated from the crankshaft, with significant deformation found on the rod bolts, rod cap, and the top of the rod. Additionally, the #5 piston pin was missing a cap. The engine's main bearings showed signs of discoloration and deformation, which is consistent with oil starvation. Further damage included scoring on the crankshaft journals, cylinder barrel scoring, and camshaft lobe discoloration. The left propeller was found in a low pitch/latch position and was not rotating at the time of impact. Analysis of the aircraft's climb performance suggested that the combination of the extended landing gear and the stopped left propeller made sustained flight impossible.