What happened
The incident occurred during a nighttime operation originating from RAF Llandwrog, also known as Caernarfon Airport. While cruising at altitude above the Snowdonia mountain range, the aircraft encountered terrain. The twin-engine machine struck the slope of Mt Mynydd Perfedd, which reaches an elevation of 812 meters. The impact forces were sufficient to destroy the airframe completely. All four individuals on board perished in the accident.
Findings
The official investigation determined that the primary factor leading to the collision was a navigation error committed by the pilot. This mistake resulted in the aircraft deviating from its intended safe altitude or path, ultimately causing it to strike the mountainside.