What happened
The incident occurred while the twin engine airplane was cruising in conditions characterized by low clouds and darkness. The aircraft impacted the slope of a mountain in the Black Hills region, specifically near Llanthony in southeast Wales. Following the collision, the airframe was destroyed. All three individuals on board sustained injuries.
Findings
The official investigation concluded that the accident resulted from crew negligence regarding flight planning. Specifically, the crew failed to prepare an adequate flight plan for the operation. Additionally, a navigational error led to the aircraft passing its intended turning point by fifteen miles. Although poor visibility due to cloud cover and darkness was present, these conditions were not cited as the primary cause of the accident.