What happened
During the cruise phase of its flight, a twin engine aircraft encountered severe weather characterized by heavy turbulence and high winds. While navigating these difficult atmospheric conditions, the aircraft suffered a catastrophic structural failure and broke apart in mid-air. The wreckage subsequently crashed in the vicinity of Mkwaya.
There were no survivors of the accident, with the crash resulting in 13 fatalities among all occupants on board.
Findings
Investigations into the wreckage revealed that the primary cause of the disintegration was a failure in the aircraft's structural integrity. Specifically, the use of an improper type of grease during the installation of press fit bolts in the booms had led to the development of corrosion nodes. This chemical reaction weakened the lower starboard boom, particularly around the outboard bolt hole.
When the aircraft encountered a significant gust of wind, the compromised section of the boom fractured at a point outboard of Station 141. This structural break triggered the complete disintegration of the airframe during flight.