What happened
Approximately thirty minutes after takeoff, a fire broke out within the left engine of the aircraft. The flight crew attempted to suppress the blaze but was unsuccessful. The fire rapidly intensified, consuming the entire engine assembly and its nacelle. This structural failure resulted in the detachment of the nacelle and caused partial collapse of the wing structure. Consequently, the aircraft became uncontrollable, entered a steep dive, and impacted the ground in a field in Cheshire. The airframe broke apart and burned completely upon impact. All 17 occupants were killed in the accident.
Findings
The official investigation determined that the immediate cause of the disaster was the in-flight failure of the left wing. This structural collapse was triggered by an engine fire, which originated from a failure of a fuel line connection. The rapid spread of the fire prevented the crew from containing it, leading to the catastrophic loss of the aircraft.