What happened
During the flight, the pilot experienced a loud bang and physical vibrations originating from the right side of the aircraft. Upon inspection, the pilot observed a hole in the right engine nacelle and an active fire within the engine. Following the discovery, the crew shut down the affected engine and initiated an emergency diversion to a nearby airfield.
As the aircraft was on final approach for landing, the engine fire reignited. The pilot successfully completed the landing and taxied the aircraft away from the active runway. After the aircraft came to a stop, the pilot shut down the left engine and evacuated the plane. Despite these actions, the fire continued to burn, eventually consuming the right engine and a significant portion of the aircraft's fuselage.
Findings
Post-accident examination of the engine revealed that the No. 2 cylinder had been displaced from the engine case, though it stayed connected via the injector lines and manifold vent tube. All eight bolts used to attach the No. 2 cylinder to the case had broken off. Significant internal damage was also noted, including a connecting rod bolt that had broken off flush within the rod, while the associated nut could not be found. The piston, cylinder, and case all exhibited numerous impact marks.
Maintenance records indicated that the engine had been overhauled approximately 4.5 years prior to the event, with roughly 900 flight hours accumulated since that overhaul. Investigators concluded that the loosening of a nut securing the connecting rod cap likely caused the cap to separate, leading to the catastrophic failure of the No. 2 cylinder.